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The Niño as a natural hazard


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The Niño as a natural hazard its role in the development of cultural complexity on the Peruvian coast
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Natural hazard research working paper ;
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Lischka, Joseph J
University of Colorado, Boulder -- Institute of Behavioral Science
Institute of Behavioral Science, University of Colorado
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Human ecology -- Peru   ( lcsh )
El Niño Current   ( lcsh )
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Includes bibliographical references (p. 55-62).
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Joseph J. Lischka.
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Includes list of the Institute of Behavioral Science's Natural hazard research working papers (p. 63-66).

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The Nio as a natural hazard
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b its role in the development of cultural complexity on the Peruvian coast /
Joseph J. Lischka.
[Boulder, Colo. :
Institute of Behavioral Science, University of Colorado],
1 online resource (v, [66] p.) :
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Natural hazard research working paper ;
v 48
Description based on print version record.
Includes list of the Institute of Behavioral Science's Natural hazard research working papers (p. [63-66]).
Includes bibliographical references (p. 55-62).
El Nio Current.
Human ecology
z Peru.
2 710
University of Colorado, Boulder.
Institute of Behavioral Science.


THE NINO AS A NATURAL HAZARD; ITS ROLE IN THE DEVELOPMENT OF CULTURAL COMPLEXITY ON THE PERUVIAN COAST Joseph J. Lischka Department of Anthropology University of Colorado August, 1983 Working Paper 148


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iii SUMMARY Assertions that marine resources of the Peruvian coast could not have supported large populations during the Cotton Preceramic period (2500-1750 B.C.) rest on tenuous and misleading assumptions. On the contrary, it can be shown that preceramic populations of the Peruvian coast depended primarily on marine resources during normal periods, and periodically shifted to agriculture during disturbances of the marine ecosystem caused by Ninos. southward along the coast. Ninos are incursions of warm surface water Anomalies in the interaction of the ocean and the atmosphere, Ninos are of varying intensities and recur on an average of once every seven years. Great Ninos occur less frequently. According to intensity, they inhibit upwelling and its rich phytoplankton content, cause fish and shellfish to migrate or die, and force higher forms of life dependent on the fish also to migrate or die. These higher forms of life can be birds, or they can be human beings. The individuals and groups living on the Peruvian coast during the Cotton Preceramic adapted to periodic maritime food shortages by turning to agriculture in river valleys to tide them over. Centralized authority developed to facilitate and maintain long-term responses to Ninos and to counter the centrifugal tendencies of a maritime-oriented adaptation. The distribution of preceramic monumental architecture along the coast supports the hypothesis.


iv ACKNOWLEDGEMENTS Part of the research for this paper was supported by a grant from the Council on Research and Creative Work of the University of Colorado. Special thanks are due to Robert Feldman, Michael Moseley, Sheila Pozorski, Tom Pozorski and Payson Sheets for reviewing a draft of the paper and providing useful information and comments.


v PREFACE This paper is one in a series on research in progress in the field of human adjustments to natural hazards. It is intended that these papers be used as working documents by those directly involved in hazard research, as well as inform a larger circle of interested persons. The series was started with funds from the National Science Foundation to the University of Colorado and Clark University, but it is now on a self-supporting basis. Authorship of the papers is not necessarily confined to those working at these institutions. Further information about the research program is available from the following: Gilbert F. White Institute of Behavioral Science #6 University of Colorado Boulder, Colorado 80309 Robert W. Kates Graduate School of Geography Clark University Worcester, Massachusetts 01610 Ian Burton Institute for Environmental Studies University of Toronto Toronto, Canada M5S lA4 Requests for copies of these papers and correspondence relating directly thereto should be addressed to Boulder. In order to defray pro duction costs, there is a charge of $3.00 per publication on a subscrip tion basis, or $4.50 per copy when ordered singly.


1 INTRODUCTION The prehistory of the Peruvian coast, in particular that period known as the Cotton Preceramic (ca. 2500-1750 B.C.), has recently become the focus of a controversy concerning the nature and potential of mari time cultural adaptations. According to Moseley (1975), exploitation of the rich marine resources of the central Peruvian coast supported large sedentary communities that exhibited varying degrees of sociocultural complexity during the Cotton Preceramic, and laid the foundations for the development of intensive agriculture and state level societies by 1000 B.C. In Moseley's view, farming was a relatively unimportant subsistence mode on the coast until the end of the Cotton Preceramic, when the development of irrigation technology led to the shift of populations inland along the coastal river valleys. Osborn (1977) and Wilson (1981) have concluded, on the other hand, that the productivity of marine ecosystems is too low to support high density populations. They argue that the development of sociocultural complexity along the coast, exemplified principally by those sites with platforms and other types of public architecture, occurred in an agricultural rather than maritime context. Wilson contends further that periodic disturbances of the Peruvian marine ecosystem caused by the Ninos produced productive bottlenecks that severely limited the human carrying capacity of that ecosystem. This paper suggests that all the arguments concerning the primacy of maritime vs. agricultural subsistence on the coast during the Cotton Preceramic are overly simplistic. They do not take fully into account the complexity and unique characteristics of the Peruvian coastal environment, and tend to ignore the ability of cultural systems to adapt


2 to temporal environmental variation. Instead, I propose that several alternative modes of sUbsistence were maintained during the Cotton Pre ceramic, and the relative importance of each of these modes varied in response to periodic resource fluctuations. The same climatic conditions (the Ninos) that temporarily reduced the carrying capacity of the marine ecosystem also increased river discharges along the coast, thus enhancing agricultural potentials in coastal valleys. It would be expected, then, that populations shifted to terrestrial modes of subsistence when significant downturns in marine productivity occurred, and returned to the primary exploitation of marine resources when the marine ecosystem recov ered (Lischka, 1975). Osborn (1977, p. 193) and Yesner (1980, p. 735) have suggested that cultural responses to periodic resource fluctuations along the Peruvian coast stimulated the development of cultural complexity and centralized leadership as means of coping with those fluctuations. The frequency and intensity of marine disturbances, however, exhibit significant variability along the coast and it seems likely that the form of cultural response exhibited similar variation. I argue that there were qualitative differences in the kinds of cultural response and that these differences are reflected by the differential distribution of monumental architecture along the coast during the Cotton Preceramic. Elaboration of this hypothesis requires an assessment of maritime resource potentials, description of relevant features of the marine and terrestrial environments of the Peruvian coast, and investigation of the responses of cultural systems to temporal environmental variation generally and to natural hazards specifically.


3 THE PERUVIAN MARINE ENVIRONMENT The marine environment of the Peruvian coast is determined largely by the Peru Current, which flows north along the coast from about 400 S to 40 S, where it veers westward away from the coast to merge with the South Equatorial Current (see inset, Figure 1). The Peru Current is produced and maintained by the counterclockwise circulation of the southern Pacific and persistent trade winds that trend north along the western coast of South America. Oceanographic and biological studies of the Peru Current, particularly off the Peruvian coast, have accelerated in recent years, stimulated largely by the importance of marine resources in the economy of Peru. Comprehensive summaries of these studies are presented by Guillen (1976), Santander (1976), Schweigger (1964), and Wyrtki (1966). Surface temperatures of the Peru Current average 17.60 C along the Peruvian coast, with local and seasonal variations ranging between 14.50 C and 200 C under normal conditions. The highest temperatures occur during the Peruvian summer, from January to March (Schweigger, 1964, pp. 93-99). This temperature range is SO to 100 cooler than open ocean surface temperatures at the same latitude and is responsible for the extension of what is essentially a temperate marine faunal and floral regime north along the coast into the tropical latitudes. Upwelling, a phenomenon that occurs primarily along the west coasts of continents and is related to the motion of the large oceanic currents, along the Peruvian and north Chilean coasts is somewhat unusual, compared to other parts of the world, in that it persists year round. Upwelling causes subsurface waters, generally from depths of 100-200 meters, to move upward to the surface. Water in the upwelling zones has a higher


." I t \ \ \ Qulf a' I Qua,.,.u.ll I I I I I I I Ta'lra: ,,...--'aUa\ \ \ Punta.' Aluja \ ... ... \ North Centr.1 o \ \ \ TruiUIQ. \ \ Clllmllclla \ \ , Soutb \ \ 100 200 I." , \ , 'r, _._ ..... '!..) _u .......... 11 .. FIGURE 1 GEOGRAPHIC FEATURES AND CITIES CITED IN TEXT, AND RIVERS LISTED IN TABLE 2 , , " I I


5 nutrient content than surrounding ocean waters and supports an extremely high rate of phytoplankton production in the euphotic zone. Estimates of the rate of carbon fixation, a sensitive measure of biological productivity, range from 45 to 200 mgC/m3 /day in the upwelling zones, compared to a rate of less than 5 mgC/m3 /day in the open ocean. Fixation rates in the Peru Current are lower than in the Benguela Current along the west coast of southern Africa, but several times higher than estimated figures for any other upwelling area in the world (Gulland, 1971, p. 137). The phytoplankton of the Peru Current are the first trophic level of one of the most productive marine food chains in the world. This food chain includes a variety of species of fish, shellfish, marine birds and sea mammals. During the nineteenth and early twentieth centuries, the principal export of Peru was guano obtained from the nesting areas of millions of marine birds on offshore islands. More recently, guano exports have been overshadowed by the export of anchovy fish meal, which by 1971 constituted about 20% of the world's fish catch. The Peruvian marine ecosystem appears to be a complex combination of two basic ecosystem types. Ecosystems of upwelling areas are relatively immature and characterized by short food chains, low species diversity, high energy flows, and low stability (Bettinger, 1980, pp. 205-206; Osborn, 1977, p. 190). Dominant species tend to be small, short-lived and fast-growing, and exhibit high rates of population increase. Population densities are usually maintained well below carrying capacity. Such ecosystems are referred to as physically controlled because population levels are controlled by the variation of relevant environmental variables. Biologically accommodated ecosystems, on the other hand, are characterized by species that are large, slow-growing and


6 long-lived. Population densities are maintained near potential carrying capacity. Energy flow through such ecosystems is relatively low because food is mainly invested in the maintenance, rather than the growth, of organisms. Biologically accommodated ecosystems are found primarily in environments with little seasonal variability. Although dominant species of the Peruvian marine ecosystem, such as the anchovy, are characteristic of physically controlled ecosystems, species diversity is relatively high and includes several large faunal species. This combination of characteristics is probably due to the stability and persistence of upwelling and to the flow of the Peru Current, both of which maintain environmental variables within relatively narrow limits under normal conditions. While there is some seasonal variation in primary productivity, seawater temperatures, and salinity, the range of variation is considerably less than that in other upwelling marine ecosystems (cf. Gulland, 1971). It would be expected, then, that species of the Peruvian marine ecosystem are stenothermal (adapted to narrow temperature ranges) and stenohaline (adapted to narrow salinity ranges), and that biological productivity is closer to potential carrying capacity than in other upwelling systems. Significant changes in these environmental variables should have correspondingly large effects on the rest of that ecosystem. Anomalies of the Peru Current The stability of the Peruvian marine ecosystem is occasionally affected by unpredictable anomalies of several types. The principal type of anomaly is the incursion of warm surface water southward along the coast. Although these warm water incursions may appear at any time, they


7 typically occur during the Peruvian summer, between January and March. These phenomena are referred to as IIEl Ninoll (The Christ Child) by coastal inhabitants because they usually occur soon after the Christmas season. According to Schweigger (1964, pp. 67-90), a true Nino is an annual warm water incursion extending south from the Gulf of Guayaquil. These annual occurrences do not usually have a marked effect on local marine fauna and flora and rarely extend south of Paita (SO S). The term is also used in the published literature to refer to occa sional appearances of the Equatorial Counter Current along the Peruvian coast (see Figure 1). These incursions first appear at a latitude of about SO S and move south along the coast, covering the waters of the Peru Current with a layer of nutrient-poor, low salinity water that may be SO 80 warmer than the water of the Peru Current. Effects on the Peruvian marine ecosystem are variable and depend on the intensity and duration of the Counter Current. Of particular interest here are the frequencies of Ninos of different magnitudes and their effects on maritime resources. There has been considerable recent research on the causes of Ninos and their effects on anchovy because the anchovy is the mainstay of the Peruvian fishing industry. Relatively little is known, however, about effects on other marine organisms. Another problem is that different sets of criteria are used by different researchers to define the nature and extent of Nino occurrences. Oceanographers use warm water temperatures as a primary criterion, meteorologists focus on climatic events, and other researchers may consider only the effects on anchovy or guano birds. These different phenomena, however, may appear independently or in combination (Prohaska, 1973, p. 106). Published references to the


8 effects of Ninos on prehistoric coastal populations rarely consider that fact, and also tend to emphasize the destructive aspects of the phenomenon (Nials et al., 1979a, b; Moseley, 1975; Osborn, 1977; Wilson, 1981; Yesner, 1980). Wilson, for example, identifies 19 livery abnormalll and at least 24 lIabnormal" Ninos between 1726 and the present (1981; pp. 101103). The interval between these events varies between six and 20 years with no regular periodicity. Wilson bases his study in part on an analysis by Quinn et al. (1978) of correlations between Ninos and climatic events of the southwestern Pacific. In their classification, strong events involve surface temperature anomalies in excess of 30 C, moderate events exhibit anomalies in the 2.00 3.50 C range, while weak Ninos are characterized by anomalies in the 1.00 2.50 C range. According to the Quinn analysis, strong Ninos occurred 23 times between 1726 and the present (1978; Table 1). According to Schweigger (1964, pp. 8788), however, the major Nino of 1891 is the earliest Nino for which we have oceanographic and climatic data. Inadequate data prior to that time make an assessment of Nino magnitude problematic. The differential effect of Ninos on marine fauna is also debated. Wilson asserts, for example, that the 1975 Nino had a devastating effect on the Peruvian fishing industry (1981, p. 95). That Nino did cause a reduction of off-shore primary production and reduced the 1975 anchovy catch by 20%; however, it had no effect on coastal upwelling nor on primary production closer than 250 km from the coast (Cowles, Barber and Guillen, 1977). Additionally, according to Quinn et al. (1978, pp. 665-666), strong Ninos seriously affect the anchovy fishing industry. Ninos classified as strong by Quinn occurred in 1941, 1957-58 and 1972, but in fact the total fish catch almost doubled from 1940 to 1941, and more than


9 doubled from 1957 to 1958 (see Table 1). The moderate Nino of 1965, however, caused a sUbstantial decrease in the fish catch. The 1972 Nino, the strongest event since 1925, dealt a blow to the Peruvian fishing industry from which it has not yet recovered. The inability of the anchovy to recover is attributed in part to overfishing. The total fish catch dropped from a maximum of 12.6 million tons in 1970 to 4.8 million tons in 1972 and 2.3 million tons in 1973. Craig and Psuty (1968, p. 16) classify the 1891, 1925 and 1953 Ninos as livery abnormalll events, while lIabnormalll Ninos occurred in 1911, 1918, 1921, 1932, 1939, 1941 and 1964. It is clear from the above that there is little agreement on the classification and effects of most Nino events. In particular, it is evident that there is little basis for Wilson's assumption that Ninos occurring every six to 20 years reduced the carrying capacity of the Peruvian marine ecosystem to one-sixth of normal. It can be said with a fair degree of confidence that the most intense Ninos, which occurred in 1891, 1925 and 1972, caused severe disturbances of the marine ecosystem along most of the Peruvian coast. Intervals between these events are 34 and 47 years. Moderate Ninos have a more limited impact on marine fauna and flora, occur more frequently than intense Ninos, and affect a smaller portion of the Peruvian coast. The effects of the 1925 Nino are described by Murphy (1926), and there are numerous reports on the Nino of 1972 (e.g., Caviedes, 1975; Ramage, 1975; Valdivia, 1976; Vildoso, 1976; Wooster and Guillen, 1974; Zuta et al., 1976). In both instances, the Equatorial Counter Current


10 TABLE 1. ANNUAL FISH AND MUSSEL CATCHES OFF THE COAST OF PERU TOTAL CATCH FISH MUSSEL CATCH YEAR (TONS) (TONS) 1939 4,800 (no data) 1940 6,400 1941 11,900 1942 21,100 1943 26,700 1944 30,300 1945 32,000 1946 27,700 1947 36,600 1948 47,700 1949 60,800 1950 83,600 1951 97,100 1952 106,600 1953 117,800 400 1954 146,100 400 1955 183,300 100 1956 265,300 900 1957 350,000 1,100 1958 930,200 1,900 continued


11 Table 1 (continued) TOTAL CATCH FISH rUSSEL CATCH YEAR (TONS) (TONS) 1959 2,152,400 2,700 1960 3,531,400 3,700 1961 5,243,100 3,300 1962 6,830,000 3,400 1963 6,900,300 3,000 1964 9,130,700 3,600 1965 7,461,900 3,900 1966 8,789,000 4,400 1967 10,133,700 5,500 1968 10,520,300 5,300 1969 9,243,600 8,400 1970 12,612,800 10,200 1971 10,606,100 10,500 1972 4,768,300 11 ,400 1973 2,328,500 14,900 1974 4,144,858 9,874 1975 3,447,490 11,906 1976 4,343,125 16,385 1977 2,529,995 11 ,317 (Food and Agriculture Organization, 1978)


12 first appeared off Talara (50451 S) and proceeded south along the coast in late January. Water temperatures 50 70 C above normal and abnor mally low salinity values were recorded as far south as Pisco (140 S) in 1972, while conditions south of Pisco remained relatively normal (Zuta 1976, p. 23). A recurrence of Nino conditions in 1973 was felt as far south as Lima (120 S). Temperature distributions during the 1925 Nino indicate abnormally high water temperatures as far south as latitudes 160 and 180 S (Murphy, 1926, pp. 27-33). As Wilson (1981, p. 103) notes, the duration of abnormal oceanographic conditions varies as a function of latitude, being longest in the north and shortest along the south coast. While these values return to normal in a matter of months, other parts of the ecosystem may take several years to recover, especially in the most seriously affected areas. The effects of intense Ninos on marine fauna vary, depending on the species involved and the type of effect. An immediate effect of the warm water incursion and the cessation of upwelling is a severe reduction or elimination of phytoplankton production. Mobile stenothermal and steno haline fish retreat to colder water under the Counter Current or migrate out of the area, effectively cutting off the food supply of other species. Guano birds, whose diet consists primarily of anchovy, begin to die off by the thousands soon after the onset of Nino conditions. Survivors abandon their nesting grounds on off-shore islands and migrate south as far as the north Chilean coast. The estimated guano bird population along the Peruvian coast was reduced from five to two million by the 1972 Nino (Vildoso, 1976, p. 67). The southward migration of guano birds is often the first indication to inhabitants of the central and south coasts that a major Nino is on the way.


i3 As indigenous species of fish disappear, they are replaced by other tropical species that normally are not found below latitude 60 S, including the skipjack (Katsuwonus pelamis), Spanish mackerel (Scomberomorus maculatus), yellowfin tuna (Thunnus albacares), dolphin (Coryphaena hippurus) and blanket fish (Manta birostris hamiltoni) (Vildoso, 1976). Changes in mobile fish species respond closely to temperature variations. As temperatures return to normal, tropical fish disappear and are replaced by indigenous species. The temporary cessation of primary production, however, results in reduced biomasses and an interruption of reproductive cycles that may take several years to overcome. One type of marine anomaly that occurs locally during the Peruvian summer and usually accompanies major Ninos is referred to as the aguaje or IIsick waterll (Schweigger, 1964, pp. 186-193). Aguajes can take dif-ferent forms but are usually caused by the same kind of dinoflaggelate blooms that produce red tides off the coasts of Florida, California and Alaska. Oxygen depletion and the accumulation of decay products during aguajes can cause mass mortality of sea life. The anomalous conditions of a Nino create more extensive dinoflaggelate blooms. Paralytic shellfish poisoning is often associated with dinoflaggelate blooms off the coasts of North America, but Gymnodinium splendens, the dinoflaggelate species usually found in Peruvian blooms, is not toxic, and there are no recorded instances of paralytic shellfish poisoning along the western coast of South America (Blasco, 1975; Dale and Yentsch, 1978). Wilson (1981, p. 113) assumes that shellfish are as severely affected by Ninos as fish. Shellfish, however, occupy a littoral (along the shore) habitat and are subjected to a more variable environment than the fauna of the sub-littoral zone and the open ocean; as a consequence,


14 shellfish are adapted to a wider range of environmental conditions (Gunter, 1957, p. 163). The most likely effect of Ninos on shellfish and other sessile species of the littoral zone is an interruption of repro ductive and growth cycles caused by elevated seawater temperatures and a reduction of food supply. Reductions in the biomass of these species would not reach significant levels until some time after the occurrence of a Nino. This conclusion is supported by examination of annual variations of the Peruvian mussel catch (see Table 1). Reductions in the catch occurred two years after the moderate 1953 Nino, three years after the 1957-58 Nino, three years after the moderate 1965 Nino, and two years after the 1972 Nino. We may conclude, then, contrary to Wilson's assertion, that shellfish were available as a food source during and immediately after a Nino. The scallop (Pecten spp.) is an exception to this conclusion. Unlike other shellfish, scallops are mobile and can move to deeper, colder waters when conditions become unfavorable. While on a visit to Peru in 1976, I observed the profile of a test pit that had been exca vated some years previously in a shell mound at Otuma south of Pisco. The profile consisted entirely of closely packed scallop shells, except for two thin lenses of mussel shells. One possible reason for the presence of the mussels is a temporary disappearance of scallops caused by anomalous conditions, forcing a temporary dietary shift. Marine Productivity and Carrying Capacities According to Osborn (1977, p. 179), the distribution of preceramic sites along the Peruvian coast between 70 and 120 S coincides with the areas of highest marine productivity. This estimate of marine produc-


15 tivity is based on the distribution of phosphate and zooplankton concentrations, and on variations in the width of the continental shelf (1977, pp. 192-193). Other data, however, suggest a wider latitudinal range of high marine productivity. Significant zones of upwelling, for example, occur between 9 0 and 150 S in the summer and between 50 and 160 S in the winter (see Figure 1). The most persistent upwelling occurs between latitudes 140 and 150 S (Guillen, 1976, p. 257-258). Areas with the highest rate of primary production are located at 80 and 150 S, with high values occurring generally between 60 and 170 S (Guillen, 1976, p. 253). Schweigger (1964, pp. 16-18) defines a depth of approximately 145 meters as the outer limit of the continental shelf. Shelf width varies between 5 and 10 km north of Punta Aguja (5050. S). It becomes consider ably wider south of that point, measuring 115 km wide at Chimbote (90 S) and 64 km at Lima (120 S). The shelf narrows to about 8 km at Pisco (140 S) and averages' about 8 km wide south to Chile. While there is some degree of correlation between shelf width and the frequency of preceramic sites along the Peruvian coast, the degree of correspondence is not particularly close. There is also a relatively high frequency of coastal sites with demonstrated dependence on marine resources along the north coast of Chile, which has a narrow continental shelf (True, 1975). A number of studies have been conducted on marine species important in the Peruvian economy, but relatively little is known about species likely to have been exploited by coastal preceramic populations. Ideally, one should have information on the distribution, density and nutritional values of all exploited faunal and floral species and on the costs and effort involved in getting them. In the absence of such information, more indirect measures of resource potential must be used.


16 Unfortunately, the use of such measures allows the possibility of selecting and emphasizing data that support one's argument and ignoring those that don't. A case in point is Wilson's (1981, pp. 104-105) evaluation of the carrying capacity of the Peruvian marine ecosystem for subsistence level human populations. Based on a set of IIbest casell assumptions, Wilson calculates a carrying capacity of about eight persons per kilometer of coastline, which is considerably lower than Moseley's population estimates for the Ancon-Chillon area of the central Peruvian coast. Wilson assumes a productivity of 335 Kcal/m2/yr for the herbivore trophic level of the Peru Current. This figure is based on the maximum anchovy harvest of Peru during the 1960s and is an average for a 50 km-wide strip along the Peruvian coast (Odum, 1971, p. 71; Ryther, 1969). Wilson uses that same caloric density figure for the 1 km-wide strip along the coast that was probaby fished by prehistoric fishers. Marine productivity, however, tends to increase as one approaches the coast (Ricklefs, 1973, p. 640). The number of econiches on shallow sea floors, rocky bottoms and rocky headlands is higher than in the deeper waters outside the subtidal zone, i.e., greater than 50 meters depth; this results in a much more complex and more productive ecosystem that draws in predators from the open ocean (McConnaughey, 1974, pp. 39-41). There is also evidence that the level of primary production is higher in the subtidal zone (Ryther and Yentsch, 1969). The productivity of the near shore environment, then, should be significantly higher than the 335 Kcal/m2/yr average arrived at by Wilson. There is little available information on the magnitude of the difference, but a 20% increase does


17 not seem unreasonable, giving a productivity figure of 400 Kcal/m2/yr for the herbivore trophic level in a 1 km-wide strip along the coast. Ecological efficiency is a measure of the amount of food energy that passes through a trophic (nutritional process) level, and is a function of net production, assimilation, and exploitation efficiencies of the species at that level (Ricklefs, 1973, pp. 643-680). Wilson (1981, p. 104) uses an ecological efficiency of 10% for the primary carnivore level; in fact, however, ecological efficiencies vary considerably between different ecosystems and trophic 1evels. Odum (1971, p. 64) suggests, for example, that ecological efficiencies at carnivore levels may be around 20%. Ryther (1969, p. 74) assumes an efficiency of 20% for the herbivore level in upwelling areas. Ricklefs (1973, pp. 655-663) notes that carnivores generally assimilate food more efficiently than do herbivores, most marine fauna are poikilotherms (non-warm blooded) which expend less energy on maintaining body temperatures than homotherms, and marine fauna and flora expend less energy than terrestrial species on physiological support structures. He estimates that ecological efficiencies range from 1% to 5% for homotherms, and between 5% and 30% for nonhomotherms. Prehistoric Peruvian fishers, according to current evidence, generally occupied the primary and secondary trophic levels of the marine food chain and utilized the food energy that was assimilated and converted to usable biomass by herbivores and primary carnivores. The proportion of food obtained from each of these trophic levels is not known, but it will be assumed conservatively here that Peruvian fishers were secondary carnivores. Based on the above statements, we will assume that the ecological efficiency of the primary carnivore level in the


18 Peruvian food chain is 20%, which gives a figure of 80 Kcal/m2/yr available to secondary carnivores. Because humans must compete with other secondary carnivores, it will be assumed that 75%, or 60 Kcal/m2/yr, is available to human consumers. Using the assumptions made above and accepting Wilson's annual caloric requirement for one person of 738,395 Kcalories, we can conclude that 12,307 m 2 of the sea within a distance of 1 km from the coast will support one person for one year. It follows that 1 km2 of sea adjacent to 1 km of coastline will support 81 persons per year during normal conditions. Normal conditions on the Peruvian coast are periodically disrupted by Ninos. Wilson assumes that an abnormal Nino occurring every six to 20 years reduces marine productivity to one-sixth of normal (1981, pp. 100101). He assumes further that coastal populations adapted by limiting their numbers to El Nino carrying capacities. I argue above, however, that the marine resources used by prehistoric coastal inhabitants, at least along the central coast, were probably significantly affected by only the most intense and catastrophic Nino events, which occur about every 20 to 50 years. Population limitation is not a likely adaptive response, given the long intervals between Ninos (Yesner, 1980, p. 735). Moseley (1975) postulated an estimated population of 2,400-5,450 people for the preceramic settlements of the Ancon-Chillon area. If the population utilized the marine resources of 50 km of coastline, Wilson's estimate of eight persons per km gives a maritime potential of only 400 persons. The theoretical carrying capacity derived here of 81 persons per km gives a total maritime population of 4,050 persons, which accords well with Moseley's estimate. Wilson states that his population estimate


19 shows that a maritime subsistence base could not have supported civilized society by 1000 B.C. in the Ancon-Chillon area, a claim that he attributes to Moseley. A careful reading of Moseley shows that he does not, in fact, make such a claim, despite a rather ambiguous use of the term "civilization," nor is such a claim made here. I have only tried to show that the resource potential of the Peruvian marine ecosystem is higher than indicated by Wilson's analysis. Raymond (1981), in a quantitative analysis of food remains at several Cotton Preceramic sites in the Ancon-Chillon area excavated by Moseley, concludes that seafood was a relatively small component of the diets of of the occupants of those sites. He suggests that root crops, which leave little residue in middens, were a staple food. However, the problems inherent in current techniques used to analyze midden contents quantitatively are such that few archeologists are willing to lend much weight to the results of those analyses (e.g., Perlman, 1980, p. 287288). The difficulties involved in the recovery of fish remains, in particular, suggest that fish are almost always underrepresented in a quantitative analysis. A further consideration is the accumulation of evidence that a significant proportion of the diet of hunting and gathering societies is consumed away from base camps. Meehan, for example, notes that the food collected by the Anbara, a maritime aboriginal group living on the north coast of Australia, on foraging expeditions was almost always consumed before the group returned to the base camp (1977, p. 508).


20 Marine vs. Terrestrial Food Sources Osborn (1977) has proposed that human groups will utilize terrestrial food resources rather than marine resources whenever possible because marine ecosystems are "second rate'l relative to terrestrial eco systems. This preference, according to Osborn, is based on several debatable features of marine ecosystems: (1) there is less food energy available from marine ecosystems than from terrestrial ecosystems, (2) marine resources, particularly shellfish, give a poor return for the amount of labor expended in collecting them, and (3) marine fauna have lower protein content than terrestrial fauna. However, a closer look at these features suggests that the situation is not as simple as Osborn indicates. Osborn's claim that there is less food energy available from marine ecosystems is based on the fact that the energy available to consumers in a food chain decreases as one moves up to higher trophic levels. Terrestrial hunters and gatherers, according to Osborn, are generally consumers at the second and third trophic levels, while maritime hunters and gatherers are consumers at the fourth or fifth trophic levels. Consequently, he argues, marine hunters obtain significantly less energy than do terrestrial hunters (1977, pp. 176-177). Available food energy does decrease as one moves up a food chain, but the energy available at a particular level is also determined by the total amount of energy feeding into the system. If the energy captured by primary producers in a marine ecosystem is significantly greater than in a terrestrial ecosystem, then the higher trophic levels of the marine ecosystem can have more available energy than the low levels of the terrestrial ecosystem. The gross primary productivity of upwelling


21 zones, for example, is 6000 Kcal/m2/yr, compared to 200 Kcal/m2/yr for deserts and tundra (Odum, 1971, p. 51). The contrast is particularly evident when comparing terrestrial and marine ecosystems along the Peruvian coast. The marine ecosystem of the Peruvian coast is one of the most productive in the world, due to a combination of geographical and climatological factors. Curiously enough, these same factors produce a coastal desert that is one of the driest in the world (see the following section). It is not unexpected, then, that the maritime-oriented human populations of the Cotton Preceramic had much higher population densities than the terrestrial hunters and gatherers who preceded them (Moseley, 1975, pp. 19-37). Shellfish as a Food Resource Basic to Osborn1s argument about hunter/gatherer preference for terrestrial resources is the claim that shellfish give a relatively poor return for the amount of energy expended in collecting them (1977, p. 172-174). However, he uses the size and nutritional value of only one species of mollusk to evaluate the potential of all marine economies. He states that an adult would need to collect 494 mussels per day to satisfy the minimum daily requirement of 40 g of protein, based on an estimated weight of 1.065 g of meat for each individual mussel (Mytilus edulis) collected by Cook (1946, pp. 51-52) from San Francisco Bay. According to Cook, 7.5% of the meat is protein. Using those figures, Osborn calculates that a Peruvian coastal village of 1,500 persons would have to collect 741,000 mussels per day, assuming they ate nothing else. Faced with this, one wonders why the villagers didn1t walk into the sea and end it all.


22 Published accounts concerning the sizes and food values of other shellfish species and the techniques used to collect them give a more optimistic picture of mulluscan resource potentials than that presented by Osborn. The average meat weight of individual Pismo clams (Tivela stultorum) collected by the California Department of Fish and Game during the last 40 years from Pismo Beach ranged from 8.0 g for one and one-half year old specimens, to 215.0 g for ten and one-half year old clams (Tomlinson, 1968, Table 3). However, few,clams over age six appeared in the samples and the average meat weight at that age is 146.0 g. Littleneck clams (Chione spp.) from the beach near San Onofre in southern California averaged 8.51 g of meat per clam (Frey, 1971, p. 24). Cook (1946, p. 51-52) obtained average meat weights of about 8.5 g for a sample of 40 clams (Macoma nasuta) from San Francisco Bay. Abalone give the highest meat weights per specimen compared to other commonly available mollusks; commercial specimens of the green abalone (Haliotis fulgens) averaged 903.7 g, and pink abalone (Haliotis corrugata) averaged 601.4 g in a study conducted by Bonnot (1948, p. 165). There is considerable variation in the protein content of different species of shellfish, and the same species can exhibit significant seasonal variation. The following figures are average protein percent ages of meat weight compiled by the U.S. Department of Agriculture for different classes of shellfish: 18.7% for abalone, 11.1% to 14.0% for clams, 14.4% for mussels, and 15.3% to 23.2% for scallops (Watt and Merrill, 1963, Table 1). Based on the weight and protein figures cited above and a 40 g daily protein requirement, an adult would only need to eat two six-year old Pismo clams, or 40 littleneck clams per day, while one green abalone provides over four days worth of protein. These


23 figures illustrate the potential bias in using the nutritional value of one species of shellfish to assess the potential of maritime subsistence systems everywhere. Nutritional comparisons based only on protein can also be mislead ing. Koloseike (1969), in his review of the evaluation of the food values of mollusks in prehistoric sites, cites several factors relevant to the problem. The ratio of meat weight to shell weight, for example, exhibits significant variation between species and among individual members of the same species. The ratio is also affected by variations in water temperature and by spawning cycles. Since this kind of information is not generally available in the literature, Koloseike concludes that archeologists must conduct the basic research themselves, as Parma lee and Klippel (1974) have done for the various species of freshwater shellfish found in shell mound sites in the eastern United States. Osborn characterizes shellfish collecting as a labor-intensive activity. The amount of labor expended, however, depends on the habitat and behavior of individual species, and most species of clams and mussels are not particularly hard to collect (cf. Perlman, 1980, pp. 286-290; Yesner, 1980, p. 730). Most species of beach-dwelling clams are located in easily accessible intertidal areas and can be collected using rakes, shovels, or the prehistoric equivalent. Potato forks are usually used in California to locate and dig up Pismo clams, but they can also be collected by moving one's feet back and forth in the surf (Frey, 1971, p. 25). Professional fishers working Pismo clam beds with potato forks at San Quintin in Baja California each collected from 36.4 to 127.3 kg of clam meat during an average low tide (Aplin, 1947). Assuming one low


24 tide per day, each of these fishers could collect enough clam meat to satisfy the daily protein requirements of between 101 and 446 adults. Abalone are harvested commercially today along the California coast by divers working at depths from six to 55 meters. However, they were collected aboriginally in the intertidal zone, and sport fishers still do the same today (Frey, 1971, pp. 31-33). Scallops (Pecten spp.) were probably more difficult to collect aboriginally because they prefer deeper waters beyond the intertidal zone. Nevertheless, they were a preferred molluscan resource in some localities, possibly because they have a higher protein content than most other shellfish species. The mounds at the site of Otuma on the south coast of Peru, for example, consist almost entirely of Pecten pupuratus shells, despite the fact that other shellfish species were present (Engel, 1957, pp. 58-59). Shellfish are a secondary source of protein for the Anbara, but they do think of shellfish as an important food. They locate their camps close to shellfish beds because they are a dependable resource that is available year round, and because shellfish can be easily collected by a broad spectrum of the population (Meehan, 1977, pp. 524-527). Meehan estimates that a skilled woman could collect about 2000 Kcal of shellfish in about two hours, or about 500 g of protein (1977, p. 524). While shellfish are a relatively good source of protein, they have a low caloric content. Wilson estimates that 10 ha of shellfish beds on the Peruvian coast would satisfy the annual caloric needs of only 13 adults (1981, p. 106). However, if we discard his notion that Ninos reduce maritime carrying capacities to one-sixth of their normal levels, the caloric carrying capacity is 79 persons per 10 ha. Wilson based his estimate on the productivity of Rangia cuneata clams in a Texas estuary,


25 which produce 2900 kg of meat per hectare annually (Odum, 1971, p. 360). This represents from 322 to 400 kg of protein per ha, using the protein values for clams cited above. Ten ha of those clam beds would provide the annual protein needs of between 220 and 274 adults. It should not be necessary to point out that no known society subsists, or has subsisted, entirely on shellfish. Coastal environments are characterized by high species diversity and a variety of potential marine and terrestrial resources. Shellfish are only one of a number of available food resources, and generally appear to be utilized as supplements to other food resources with higher caloric values, or as an important back-up food source when others are in short supply (Perlman, 1980, pp. 286-290). THE TERRESTRIAL COASTAL ENVIRONMENT The relatively cool water of the Peru Current, the prevailing trade winds, and the presence of the Andean mountain chain combine to produce a terrestrial coastal environment characterized by exceptionally low precipitation, high relative humidity, persistent cloud cover during the Peruvian winter (June through October) and small daily temperature variations. Annual precipitation varies from 25 to 100 mm between 50 and 90 S, and between a and 25 mm south of latitude 9 0 S (Schweigger, 1964, p. 134). According to Prohaska (1973, p. 92), the lack of precipitation is caused by a persistent atmospheric inversion that prevents the development of convective air currents. The inversion also prevents the upward transport of water vapor, resulting in high atmospheric humidity under the inversion and persistent cloud cover along the coast. The saturated air under the inversion intersects the ground surface at elevations


26 between 100 and 800 meters and produces ground fogs or garuas. The garuas are most prevalent between June and October south of latitude 80 s. The barrenness of the coastal desert, prior to the advent of irrigation agriculture, was relieved only by natural vegetation on the flood plains of the coastal valleys, and by vegetated areas {lomas} at eleva tions between 100 and 800 meters. The lomas are watered by the condensation of moisture from winter garuas, a process which is markedly accelerated by the greater surface area presented to the air by a vegetative cover. In the Lomas de Lachay for example, annual precipitation under casuarina trees in 1944-45 was 488 mm, compared to 168 mm in areas with only a low plant cover {Schweigger, 1964, p. 162}. Condensation on bare ground would be correspondingly less. This makes lomas particularly susceptible to grazing pressure, since a reduction of plant cover reduces available moisture, thus setting up a positive feedback cycle that hampers the regeneration of plant cover. Lomas today are found between 90 and 200 S {Craig and Psuty, 1968, pp. 123-129}. Over 50 rivers cut through the coastal desert from the Andes to the sea. They exhibit significant variations in valley size, amount of discharge, and the area and location of flood plains and irrigated land. There are also significant variations in annual river discharge {Robinson, 1964, pp. 163-182}. River discharge, which exhibits the greatest seasonal variation of any environmental coastal variable, is dependent on seasonal precipitation on the west side of the Andes. Maximum discharge occurs during the months of January to March, during the height of the rainy season in the mountains, and reaches a minimum during July and August {Robinson, 1964, pp. 165-172}.


27 Climatic Anomalies Major Ninos produce major changes in coastal climate, while moderate events have variable effects. During the 1925 Nino, torrential rains fell on the north coast of Peru from January through March, and increased rainfall was recorded as far south as northern Chile (Murphy, 1926, pp. 37-45). Rainfall in Trumillo totaled 394 mm during March, compared to annual average precipitation of less than 5 mm. The 1891 and 1972 Ninos also produced torrential rains on the north coast and increased rainfall on other parts of the coast (Caviedes, 1975; Murphy, 1926, pp. 35-37). Increased river discharges and flooding of coastal valleys, caused by increased rainfall in the mountains above the coastal plain during the 1925 Nino, occurred as far south as the Ica Valley (Murphy, 1926, pp. 4547). While high river discharges and coastal rains occur together during major Ninos, high river discharges on the north coast can occur in the absence of coastal rains (Nials et al., 1979a). The heavy rains and floods that accompany major Ninos cause exten sive destruction and the disruption of irrigation canals in coastal valleys, but have a beneficial effect on coastal vegetation and flood plain agriculture. Grasses and herbaceous vegetation flourished in normally barren areas as far south as Pisco in 1925, and provided pasturage for goats for one to two years after the Nino. Water tables were elevated in the Piura Valley and caused increased agricultural production for as long as three years after the Nino (Murphy, 1926, pp. 36-37). Similar conditions prevailed after the 1972 Nino (Caviedes, 1975, p. 504). In general, it appears that the flooding of coastal valleys during major Ninos, while causing major disruptions of irrigation systems, increases the potential for flood plain agriculture after the flood


28 waters recede. It is also likely that the quantity of potential wild plant resources in loma areas and in the coastal valleys is increased for a period of one to two years after a major Nino. One major problem is determination of latitudinal variation in the effects of Ninos. In general, intensity and duration of the oceanogra phic effects of major Ninos are highest in the north and decrease as one moves south along the coast. A similar gradient is exhibited by Ninos of varying intensity; the less intense Ninos do not extend as far south along the coast. Thus, we would expect that the north coast is affected more frequently and with greater intensity, while the central and south coasts are affected only by the rarer major Ninos. This variation of effect is reflected in the climatic data. Examination of variations in river discharges indicates that river discharge is significantly more variable north of the Viru Valley than along the rest of the coast. Table 2 lists maximum, minimum, and mean river discharges for most of the coastal rivers. A variability index wa!. calculated by dividing the difference between maximum and minimum discharges by mean discharge. The mean of the variability index for rivers from the Tumbes to the Viru is 2.52, and the mean index for all rivers south of the Viru is 1.55. The difference between the two means is significant at the 0.01 level. The number of years averaged varies from river to river, with no years earlier than 1912 or later than 1956 included (Robinson, 1964, pp. 168-171). The only major Nino during this time period occurred in 1925, but no good records of discharge are


TABLE 2. MAXIMUM, MINIMUM AND MEAN RIVER DISCHARGHES IN MILLIONS OF CUBIC METERS OF THE COASTAL RIVERS OF PERU 29 Rivers are listed sequentially, from north to south. MAXIMUM MINIMUM MEAN VARIABILITY RIVER DISCHARGE DISCHARGE DISCHARGE INDEX Tumbes 7072.6 1630.8 3787.3 1.44 Chira 11 ,035.1 1604.5 3775.7 2.50 Quiroz 2208.1 505.1 1058.0 1.61 Piura 3397.4 0.0 845.8 4.02 La Leche 394.4 93.1 208.8 1.44 Chancay 3247.1 459.8 917.2 3.04 Zana 626.6 125.6 241.0 2.08 Jequetepeque 2256.8 284.2 902.2 2.19 Chicama 2484.4 263.9 979.9 2.27 Moche 563.2 76.6 300.3 1.62 Viru 799.1 40.9 137.3 5.52 Santa 7537.8 3147.7 4674.7 0.94 Nepena 148.9 33.3 69.7 1.66 Casma 333.7 16.1 183.3 1.73 Huarmey 268.7 39.1 106.4 2.16 Pat iv ilea 2352.9 975.4 1472 .0 0.94 Huaura 1244.9 569.8 908.8 0.74 Chico 107.5 30.7 59.0 1.30 Huaral 839.0 138.3 492.6 1.42 continued


30 Table 2 (continued) MAXIMUM MINIMUM MEAN VARIABILITY RIVER 01 SCHARGE DISCHARGE DISCHARGE INDEX Ch i llon 939.0 141.7 299.9 2.66 Rimac 1188.2 603.7 914.7 0.64 Lurin 349.5 23.2 141.0 2.31 Mala 1250.4 89.9 565.9 2.05 Canete 2844.0 869.7 1754.9 1.13 Ch incha 1138.8 90.9 470.2 2.23 Pisco 1221.2 527.5 837.1 0.83 Ica 642.7 77.6 325.2 1. 74 Grande 1926.9 17.6 601.7 3.17 Acari 750.7 258.3 437.7 1.12 Yauca 575.0 148.9 286.2 1.49 Majes 3432.5 1761.8 2783.9 0.60 Colca 98.9 28.9 53.5 1.31 Vitor 1025.7 148.7 398.0 2.20 Sumbay 127.7 64.0 94.9 0.67 Tambo 3163.5 392.8 1128.2 2.46 Moquegua 102.4 32.3 59.5 1.18 Cap 1 ina 80.5 21.9 38.6 1.52 (Robinson, 1964)


31 available for that year for the Moche River, or presumably for other rivers where major flooding occurred (Nials et al., 1979a, p. 10). While the frequency of variations in river discharge cannot be determined from the data, the results of the analysis indicate that rainfall is significantly more variable in the watersheds of the north coast rivers, whether produced by moderate Ninos or other climatic variation, than along the rest of the coast. Prehistoric Environment An important question is the degree to which the environment of the Peruvian coast today approximates the environment during Cotton Preceramic times. Fossil lomas are considerably more extensive than active lomas today. Lanning (1967, p. 51) feels that the fossil lomas represent a wetter between 6000 and 2500 B.C., while Parsons (1970, pp. 300-301) attributes the fossil lomas to expansion during Nino years. Cohen (1978, p. 26), on the other hand, proposes that a reduction in lorna size has occurred, but attributes it to overgrazing since the Conquest, rather than climatic change. Craig and Psuty (1968, p. 154) also disagree with Lanning's hypothesis of climatic change, arguing that the xeric (dry, desert-like) adaptations of coastal plant communities indicate arid conditions for at least the post-Pleistocene period. Craig and Psuty (1968, p. 154) suggest that the weather and circulation system of the southern Pacific are unlikely to have undergone sufficient change since the end of the Pleistocene to modify coastal aridity significantly. Sarma, however, postulates a definite cycle of wet and dry periods during the last 8000 years on the west coast of South America. He sees evidence of two pluvial peaks during the Cotton


32 Preceramic, at 2600 and 2000 B.C. (1974, p. 114). During these pluvial periods, river flows in the coastal valleys of Peru would have been greater than they are today and the extent of lorna areas would have been greater (p. 124). Additionally, Ninos would have occurred with greater frequency and would have extended farther south along the coast. Sarma bases his analysis on variations in the frequency of mangrovedwelling mollusks in the different strata of shell middens on the Santa Elena Peninsula of southwestern Ecuador. The shellfish frequencies, according to Sarma, reflect variation in the extent of mangrove, which i1 turn is a function of changes in rainfall. Ferdon (1981), however, argues against the validity of Sarma's climatological interpretation by showing that variations in the rate of mangrove formation on the penin sula can also be explained as a response to tectonic uplift and other changes in shoreline topography. According to Paulsen (1976), the begin ning of wetter conditions in 1970 on the Santa Elena Peninsula is evidence of a dramatic reversal of an increasingly drier climate during the twentieth century. In fact, the increase in rainfall, which reached a maximum in 1972, is probably a relatively short-term change related to the major Nino of 1972. The conflicting interpretations cited above indicate that more information on Holocene climatic changes is needed. The basic climatic pattern remains, however, one of exceptional aridity along the Peruvian coast with unspecified but minor variations in river flows and Nino frequency. These possible variations do not appear to be a significant factor with regard to the hypothesis presented here.


33 NATURAL HAZARDS CHARACTERISTICS Recent developments in natural hazards research and the investigation of cultural responses to environmental variation indicate that extreme events are at least as important as average conditions in the analysis of human adaptive processes (Vayda and McKay, 1975; Winterhalder, 1980). An extreme natural event is defined as any event that displays relatively high variance from the mean. An extreme event becomes a hazard when it requires some degree of human response to reduce the negative impacts of the event (White, 1974, pp. 3-4). The type of response made may vary from acceptance of losses to complete avoidance of the event by permanently migrating out of the area affected by the event (Burton, Kates and White, 1978, pp. 45-49). The type of response depends, to an extent, on the nature of the event. Hazard characteristics considered relevant by Burton, Kates and White (1978, pp. 22-24) for a study of human adaptive responses include magnitude, freguency, duration, areal extent, speed of onset and temporal spacing. A basic distinction is also made between pervasive and intensive hazards; for example, drought is a pervasive hazard, and a tornado or flood an intensive one. As noted earlier, Ninos exhibit a continuum of latitudinal variation with regard to the characteristics described above. For the purpose of discussion, however, a basic distinction will be made between the north (north of 90 S), central (90 to 130 S), and south (south of 130 S) coasts. Differences in Nino characteristics between these different zones are summarized below. Ninos as Hazards Magnitude. The magnitudes of individual Ninos vary from minor events with minimal effects to the occasional major event, such as the


34 1925 NiOo. Nials et ale (1979a) describe a Nino occurring sometime around A.D. 1100 whose magnitude, judging from the degree of flooding, was several times greater than the 1925 event. Degree of effect on depends in part on duration of the event. Frequency. Major Ninos occur about once everyone or two generations. Moderate and minor Ninos occur more as often as every five to ten years. Major Ninos affect the entire Peruvian coast, while moderate and minor Ninos affect only the north coast. Duration. Duration varies with respect to magnitude and latitude. Duration of the primary and secondary effects of major Ninos may be as long as several years, particularly on the north coast. Occurrence of a minor event immediately after a major Nino may impede recovery of the marine ecosystem, as happened in 1973. Areal extent. This characteristic refers essentially to the latitu dinal extent of a Nino and is a function of magnitude. Also included are effects on the terrestrial environment. Rainfall accompanying major Ninos may affect the entire watersheds of coastal rivers. Correlations of Nino events have been made with variations in Andean climate and world-wide weather patterns (cf. O'Brien, 1978), but they are not directly relevant here. Speed of onset. This characteristic refers to length of time between the first appearance of an event and its peak. As noted, effects on most marine fauna and on terrestrial climate appear quickly. Other effects, such as reduction of shellfish biomass, may show varying degrees of lag. The effects of major Ninos show a progression down the coast, occurring several weeks later on the central coast than on the north coast.


35 Temporal spacing. This characteristic refers to the randomness of events through time and is related in some degree to the predictability of an event. Ninos typically occur during the summer, but intervals between events, particularly the major ones, exhibit little regularity. It has not been possible to predict when a Nino will occur or what its intensity will be. The randomness of such events and the lack of lead time are critically important variables in choosing viable responses. A recent hypothesis concerning the causes of Ninos suggests that major events are preceded by one to two years of exceptionally strong trade winds and are accompanied by a marked decrease in trade wind strength (O'Brien, 1978, pp. 44-45). If the hypothesis is valid, changes in trade wind patterns may have provided as much as several months of advance warning. Pervasiveness. Pervasiveness is related to duration and areal extent. Ninos, like droughts, fall near the pervasive end of the perva sive-intensive continuum. Responses made to pervasive events tend to be long-term adaptations rather than short-term adjustments. Influences on Choice of Response It is assumed that selection of appropriate hazard responses by a group is not a random process, but one that involves some consideration of hazard characteristics, population level, and social needs, as well as an evaluation of the costs and benefits of various responses. Selection is also affected by the type of group responding. Population level. Although estimates of coastal population size during the Cotton Preceramic vary, there is common agreement that there were relatively high rates of population increase during that period (Bray, 1976, pp. 84-85; Moseley, 1975, pp. 60-62; Patterson, 1971,


36 p. 319), at least between Chimbote (90 S) and Lima (120 S). Preceramic sites on other parts of the coast are relatively small and scattered, suggesting relatively low population densities. This impression may be due, however, to the lack of adequate surveys in those areas. There is little archeological evidence for Wilson's (1981, p. 114) assertion that central coast populations maintained their numbers below Nino carrying capacities. In any case, such a response seems unlikely, given the long intervals between Ninos. As population increased during the Cotton Preceramic, it is probable that succeeding Ninos had increas ingly greater impacts on coastal groups, necessitating the adoption of more comprehensive and reliable responses. Cultural context. Bray (1976, pp. 90-91) contrasts the types of hunting and gathering subsistence systems found in variable environments with those in stable environments. In variable environments, where the availability of individual resources may be unpredictable, a secure food input is ensured by exploiting a wide range of resources. In stable environments with dependable resources, subsistence activities are focussed on a smaller range of resources that provide the greatest returl for a given amount of effort. The shift from a generalized to a specialized subsistence orientation on the central Peruvian coast is illustrated by a change in settlement location from lorna zones to the coast at the beginning of the Cotton Preceramic. The change in settlement location apparently reflects a change in subsistence strategy from the generalized exploitation of lorna, coastal valley and maritime resources, to the more specialized utilization of maritime and valley flood plain resources, including domesticated plants (Cohen, 1978). Coastal specialization was reinforced


37 by the stability of the coastal environment. On the south coast, domesticated food plants were not utilized until long after the Cotton Preceramic and a generalized exploitation of lorna and marine resources continued. A maritime adaptation in a stable environment is normally character ized by small group size, small settlements and relatively simple social organization, the kind of situation inferred for the south coast and the earliest preceramic settlements on the north and central coast. Selec tion of appropriate Nino responses, then, would initially be made in a cultural context of simple social organization and small group size. Tendencies toward simple social organization and small group size during normal periods could also be expected to work against the maintenance of Nino responses requiring greater degrees of organization and centralized authority. Such tendencies may have necessitated the use of reinforcement mechanisms, such as ritual, to maintain Nino response capability. Evaluation of the importance of agriculture during the Cotton Preceramic is complicated by a relative lack of information. Remains of a number of cultigens--including cotton, squash, lima and common beans, gourds, sweet potatoes, and achira--are found in Cotton Preceramic sites on the north and central coasts. The food plants, however, are not found in sufficient quantity to indicate they were used as staples. The evidence for maize cultivation during the Cotton Preceramic is questionable (Feldman, 1982). If it was cultivated at all, it was evidently not an important element of coastal agriculture. Water scheduling is more critical for the successful cultivation of maize than for any other field crop (Klages, 1942, pp. 205,394-395); maize also has a relatively shallow root system. These characteristics suggest that maize would be


38 difficult to grow where water cannot be controlled is available only from water tables under flood plains in coastal valleys. It would be expected, then, that maize was not extensively cultivated on the coast until the advent of irrigation agriculture. Raymond (1981, p. 814) suggests that root crops, particularly (Canna edulis), may have been grown as staples by coastal inhabitants. The cultivation of root crops is non-seasonal in nature and would be compatible with the exploitation of marine resources than would be the cultivation of seasonal seed crops. High-carbohydrate root cultigens would also complement relatively high-protein, low-calorie marine resources. However, Raymond's hypothesis that central coast inhabitants had an agricultural subsistence base does not account for the existence of preceramic sites such as Rio Seco, which is not located near any valley flood plain (Wendt, 1964). Evaluation of arguments for and against the importance of agricul ture and a weighing of the evidence suggests that cultigens were secondary in importance to maritime resources during the Cotton Preceramic, at least during normal periods. The possibility is not elirr inated, however, that agriculture was of primary and even critical impor tance during Ninos. Hazard perception. Research on the perception of hazards by indivi duals indicates that expectations of future occurrence and attitudes concerning personal vulnerability are related to the magnitude and frequencyof an event and how recently the last event occurred. In general, the lower the frequency of an event and the longer the time since the last event, the greater the tendency to ignore the probability of future events and to underestimate their potential effects (Burton, Kates and


39 White, 1968, pp. 15'-17; Kates, 1970, pp. 6-7; Mileti, Drabek and Haas, 1975, pp. 23-26; Payne and Pigram, 1973, pp. 3-6). Ignoring a hazard, however, does not reduce the probability of its occurrence. The collective "memory" of a group is a more reliable basis for action than individual attitudes. The group, in a sense, acts as a mechanism for information storage by creating formal procedures for recording exper ience of an event and of possible warning signals (Burton, Kates and White, 1978, pp. 130-131). Rappaport (1971) emphasizes the use of religious ritual in folk societies to communicate and validate information, and it seems likely that ritual was also used to store information. Costs and benefits. Payne and Pigram (1973, pp. 42-43), in a discussion of decision-making models, conclude that the "subjective expected utility" model is most relevant to the analysis of hazard response. According to this model, individuals decide between different responses by evaluating the utility of each response with respect to the probability of occurrence of a future event. Evaluation of utility is conditioned by hazard perception and culture context. In general, the choice of a long-term response is constrained by the cost of maintaining the response during normal periods and by potential conflicts with adaptations made to normal conditions. Low event frequencies and specialized adaptations made to stable normal environments increase the magnitude of the constraint. Long-term responses may even be ignored in favor of short-term emergency responses, a tendency which is more prevalent at the individual than at the group level. Choices between long-term and shortterm responses are also conditioned by the speed of onset of an event and the amount of advance warning. Short warning times and fast onsets favor long-term response.


40 Level of response. The activation and management of a specific hazard response can be carried out at different levels--individual, household, residence group, entire social system--depending on hazard characteristics, cultural context, and the degree of management and control needed to implement a response. A related concept is centralization of management and control. Rappaport (1971, p. 66) proposes that rapidly changing environments require rapid and flexible response mechanisms. Speed and flexibility of response is particularly important in coping with hazards that occur with little warning. Centralization of authority in a chief or religious figure can provide these qualities, at the cost of maintaining individuals in those roles. If the cost of main taining centralized authority is less than the costs of other possible responses, then centralized authority is likely to be chosen, all other things being equal. As an example, food storage as a response to possible resource shortages can be carried out at any level. Members of a society, rather than maintain food reserves in households, may decide that it is more efficient to maintain public food stores. Such a response would also eliminate the potentially divisive situation wherein some households had food and others did not during a crisis. NINO RESPONSES DURING THE COTTON PRECERAMIC I propose that choices of specific Nino responses were made according to the factors outlined above, and that the kinds of responses selected varied as a function of latitudinal variations in Nino characteristics, particularly magnitude, frequency and duration. The scenarios outlined below for the central, northern and southern coasts are idealized event sequences. Behavioral trajectories in any human system do not exhibit unilinear precision, and any model of human behavior will


41 be an approximation of a fuzzier real world. Neither is it suggested that Nino responses are the only determinants of human behavior on the Peruvian coast during the Cotton Preceramic. The Central Coast The evidence indicates that the central coast is affected only by major Ninos occurring one or more generations apart. The magnitude of major Ninos is large and effects on resources may persist for several years. Heavy rains, flooding and problems with marine resources occur within a few weeks after first appearance. Environmental conditions between Ninos exhibit a high degree of stability and little seasonal variability. Coping with a Nino during the early part of the Cotton Preceramic may have entailed little more than a temporary shift to the exploitation of shellfish and the expanded wild plant food resources of the lomas and coastal valleys, assuming low population levels. As population increased, however, there was an increased need for more comprehensive Nino responses. The factors outlined above favor group level, long-term responses that could be maintained at minimum cost between Ninos and which conflicted least with "business as usua1." At the same time, it was necessary to implement or activate the response in a short period of time. I propose that the primary response meeting these criteria was a full-scale subsistence shift during a Nino from a maritime to an agricultural subsistence strategy directed and controlled by a centralized figure of authority or group of individuals. Within a short time after Nino onset, flooding washed out existing crops on valley flood plains. The floodwaters soon receded, however, leaving a high water table and


42 favorable conditions for expanded flood plain agriculture. Fields had to be quickly planted, requiring the mobilization of large numbers of people and a supply of cu1tigen seeds and root crop cuttings that were held in reserve. Seeds lose their fertility relatively quickly in the high humidity climate of the coast, and a certain level of agricultural activity had to be maintained during the intervals between Ninos to ensure the viability of seeds and root cuttings. Why not simply maintain a permanent fully agricultural economy? Because it was more efficient to exploit marine resources during stable periods, except for the cultivation of needed industrial products, and because the agricultural potential of flood plains was less during normal periods. It is possible that seeds and root cuttings could have been obtained from agricultural groups in neighboring areas or the highlands; however, it seems more probable that coastal populations would have wanted to maintain control of seed production rather than depend on other groups for such a critical resource, especially considering that it woulc have to be available within a relatively short time. If coastal sites were located near valley flood plains, the logistics of switching subsistence strategies and maintaining a minimal level of agricultural productivity were relatively simple. If flood plains were located some distance from coastal settlements, however, the situation wou1d have been more complex. A major shift to agriculture during Ninos would require relatively large population movements from the coast to flood plain areas. These populations would gradually move back to the coast as marine conditions normalized, leaving behind a smaller contin gent at the flood plain site to continue a lower level of agricultural production and to maintain a seed and root crop reserve.


43 It might be argued that such a situation fits Patterson's (1971) model of exchange links between coastal valley farming settlements and coastal fishing villages. While exchange links might be adequate for normal periods, it would seem that a stronger tie was needed to cope with Ninos. Why should valley farmers tolerate the influx of population and resultant shock to their resource base and social system that would occur during a Nino? Incorporation of both types of settlement into the same complex socia-political system would be more stable and would enable a smoother transition between normal and Nino periods. Crops planted immediately after the onset of a Nino would not begin to produce until four to five months later, requiring some source of food during the interim. However, food storage is not a viable solution, because the continuous high humidity of the coast makes long-term food storage difficult, especially given the relatively low level of tech nology during the Cotton Preceramic. A few sources of food, however, were available. Shellfish, as was pointed out, are less severely affected by high water temperatures than other marine species and could have served as an emergency food supply. Also unaffected were the wild plant food sources of the lomas and those areas of the coastal valleys not cleared for agriculture. A second possibility was food obtained from highland populations through trade. Trade, however, is not likely to be more than a short-term solution. Highland groups themselves probably did not produce amounts of food substantially in excess of their needs. Prehistoric people were presumably no more altruistic than people are today and would have required something in exchange. One possible exchange item is cotton, which could be accumulated either in raw form or as cloth in anticipation of future exchange needs.


44 Reinforcement of public consensus and compliance with centralized authority, and the maintenance of hazard response capabilities are particularly necessary to minimize the tendency of the marine adaptation to return to simple social organization and small group size during the long intervals between Ninos. According to Rappaport (1971), ritual and religious sanctification are common reinforcement techniques used in pre state systems where authority cannot be maintained by power. Another useful reinforcement technique is an imposing visual symbol of that authority, such as a temple, platform or pyramid, that also serves as a focus of ritual activity. It is even better if large labor forces must be mobilized to build those structures, thus reinforcing and maintaining a management system that can be directed to other ends when needed. Flannery (1972) has suggested that the construction of permanent facilities, residential or otherwise, was a means of visually validating the community ownership of critical resource areas against the claims of neighboring communities. While he refers specifically to agricultural resource areas, any type of localized resource that was critical for the functioning of the system could be included. If centralized authority evolved as a response to Nino resource fluctuations, we might expect to find Cotton Preceramic monumental archi tecture associated with resources that were of critical importance during Ninos. The same sort of association would be expected if increasing cultural complexity was simply a response to increases in population density and group size during the Cotton Preceramic. There is one exception--if inland sites near flood plains were occupied only periodically, the quantity of midden would be significantly less than if the site was occupied continuously, relative to the scale of monumental architecture


45 at the site. Additionally, if long-term responses to Ninos involved the accumulation of cotton textiles or raw cotton and the maintenance of seed and root crops reserves, we would expect to find storage facilities at sites near flood plains, either on the coast or inland. The North Coast The north coast is affected by major, moderate and minor Ninos. The effects of major Ninos persist longer than along the central coast, and Nino rains and flooding are more intensive. Moderate and minor Ninos occur more frequently, are of shorter duration, mayor may not be accompanied by coastal rains, and probably have some effect on river discharge. The overall effect is a more variable terrestrial environment and a less stable marine ecosystem over the long run than along the central coast. These factors favor individual Nino responses and a greater average dependence on agriculture, relative to the exploitation of marine resources. There would be less emphasis on centralized authority in the north because agriculture was a more integrated part of the subsistence system. As a consequence, valley flood plain settlements would be larger and more numerous relative to coastal settlements, and examples of monumental architecture would be smaller, less frequent or absent. Population density may have been as high as along the central coast, but estimates based on archeological site size and frequency may be low due to the lack of monumental architecture and the destruction of valley settlements by later irrigation agriculture. The greater dependence on agriculture hypothesized for the north coast suggests that irrigation technology may have appeared earlier In the north coast than farther south. The proposed relationship between


46 irrigation and maize on the coast indicates that the substantive cultivation of maize also may have occurred earlier on the north coast. These events, however, could have occurred sometime after the end of the Cotton Preceramic. The South Coast Judging from the distribution of recorded sites, population density along the south coast remained relatively low during the Cotton Preceramic. Upwelling and primary production was evidently as high as elsewhere, but shoreline conditions may have been less' favorable for the exploitation of marine resources, at least south of th Paracas Peninsu16 (Willey, 1971, p. 202). River valleys are also spaced farther apart anc: have considerably smaller flood plains (Raymond, 1981, p. 817). As a consequence, agriculture never achieved a foothold on the south coast unti 1 the advent of irrigation technology. Only the biggest Ninos, occurring perhaps less than once a century" affect the marine ecosystem of the south coast and the effects do not last as long as on the central and north coasts. Given a low population density, the most likely Nino response would have been a greater emphasis on wild resources of the lomas or temporary migration to other areas. THE ARCHEOLOGICAL EVIDENCE The construction of monumental architecture most frequently require the efforts of corporate labor groups directed by some kind of centralized authority. Moseley (1975, pp. 79-80) defines two major types of preceramic corporate-labor construction--residential and non-residential. Residential corporate-labor construction included the large-scale terracing of residential sites and substantial residential structures


47 with stone or clay walls. Substantial residences were not required for protection from the mild climate of the Peruvian coast. Non-residential corporate-labor architecture included platforms, buildings, and terraces that were not primarily used for residential purposes. Cotton Preceramic sites with definite examples of corporate-labor residential architecture are found on both the north and central coasts, for example, Huaca Prieta de Chicama, Culebras, Aspero, and Punta Grande (Moseley, 1975, pp. 91-92). More ambiguous or smaller scale examples include stone or clay-walled structures at Alto Salaverry, Huaca Negra, Rio Seco and Asia (Lumbreras, 1974, pp. 41-44; Pozorski and Pozorski, 1979; Willey, 1971, pp. 96-100). In general, the most substantial and representations of corporate-labor residential architecture are found along the northern part of the central coast (see Figure 2). Cotton Preceramic sites with non-residential architecture are, from north to south, Alto Salavery, Salinas de Chao, Culebras, Aspero, Piedra Parada, Bandurria, Rio Seco and El Paraiso. Lumbreras (1974, p. 43) identifies a plaza and platform complex at the site of Las Haldas as Cotton Preceramic, but Matsuzawa (1978) has demonstrated that most, if not all, of the monumental architecture at the site was constructed after the end of the Cotton Preceramic. In general, the scale of the non-residential corporate-labor architecture increases as one moves south, culminating in the most impressive example of preceramic architecture at El Paraiso, on the south central coast. At Alto Salaverry, located on the north coast in the Moche Valley, one circular subterranean structure and two rectangular room complexes have been excavated (Pozorski, 1975, pp. 2-4). Moseley (1978, p. 14) describes Salinas de Chao as one of the smallest of the coastal


eO La,end orc_CItIlul 0111 .ape,o Pled,a Pa,ada Bandu"la RloSeco rill_III' orchilielurl ftD". rllldO"U"'"rcIlKeclure o 100 200 kllo",.I.r. 300 N FIGURE 2 LOCATIONS AND ARCHITECTURAL CHARACTERISTICS OF COTTON PRECERAMIC SITES NOTED IN TEXT


49 preceramic sites with platform mounds. Non-residential architecture at Cu1ebras consists of several stone structures built on terraces (Lumbreras, 1974, p. 43). South of Cu1ebras, the non-residential architecture at Aspero and Piedra Parada is second only to E1 Paraiso in size and extent. Aspero is located on the north side of the Supe Valley near the coast. Piedra Parada is located on the south side of the valley about 3 km inland and is clearly visible from Aspero. Excavations in two of the mounds at Aspero uncovered extensive masonry complexes of large and small rooms grouped around small courts, with restricted access to interior rooms (Feldman, 1977). Bin-like structures averaging 1.2 to 1.9 m in diameter, and from 1.0 to 1.3 m in depth were found at unspecified locations on the site, and Moseley (1978, p. 82) suggests that they may have been used for storage. Piedra Parada, which was established somewhat later than early occupation at Aspero, consists of three masonry room complexes, the largest of which is 80 meters square (Fe1dman,1977). Midden accumulations at Piedra Parada are relatively shallow, indicating that the architectural complexes were built by populations residing elsewhere. Bandurria and Rio Seco are located on the coast at least 10 km from the nearest arable land. At least two well-defined platform mounds are present at each site. Excavation in one of the mounds at Rio Seco shows that it began as a room complex that was filled in and a new room complex built on the top. Midden accumulations and burials at each site suggest resident populations of several thousand people (Moseley, 1978, p. 14). E1 Paraiso consists of at least eight large mounds of rubble and associated midden located along the Chi110n River about 4.5 km from its mouth. One of the mounds has been excavated and partially restored by


50 Engel (1966), who discovered it to be a large complex of rectangular rooms underlain by five or six previous building stages. The largest room contains a rectangular basin in the floor, with circular stone-lined pits at each of the corners, and circular clay-lined pits were also found in other parts of the complex (1966, p. 50). Evidence of hearths was only found in the largest room. Engel estimates that there were 90 ha of nearby land that could have been cultivated without irrigation, and he mentions the existence of flood plains five km upriver that are associated with preceramic sites (1966, pp. 58-59). The midden at El Paraiso, however, is less than would be expected for such a large site (Moseley, 1975, p. 97). The distribution of sites with residential and non-residential corporate-labor architecture generally agrees with the hypothesis that emphasis on centralized authority and administration increased as Nino frequency decreased south along the coast. Where along the coast such a response ceased to be effective is not clear, but the transition evidently occurred somewhere south of the Chillon Valley. Piedra Parada and El Paraiso provide the best evidence in support of the Nino response hypothesis. They are both located some distance inland and consist of large masonry room complexes that may have been used either for storage or as elite residences. If the complexes were roofed, however, the interior rooms would have been quite dark, making them unlikely habitations. The midden at both is less than would be expected, given the amount of labor that was expended on the masonry structures. El Paraiso is located near a large flood plain area, but the amount of flood plain near Piedra Parada is unknown. The room complexes and bins at Aspero could also have been used for storage, but since it is near the


51 coast, the population would have remained at the site both during normal periods and Ninos, thus explaining the relatively deep midden there. As the growing population of Aspero began to exceed the capacity of the limited amount of flood plain near the site, I suggest that Piedra Parada was built near other flood plain areas upstream. The non-residential architecture at Rio Seco and Bandurria is similar to that at Aspero, Piedra Parada and El Paraiso, but is smaller in scale. Although the two sites are not located near any flood plain areas, they could have been associated with agricultural activities in adjacent valleys or the nearby Lomas de Lachay. If the room complex at Rio Seco was used for storage, however, it is not clear what would have been stored. The critical resources at Rio Seco would probably have been marine resources that do not store well. Ninos leave little record of their passing in the archeological record. There are two ways, however, that changes in activities caused by Ninos may be detected. Presence of the remains of tropical species of birds and fish in midden deposits that are only present along the coast during Ninos would constitute one form of evidence. A second technique depends on the analysis of 0-18/0-16 ratios in the carbonate of mollusk shells. The ratio varies as a function of the temperature of the water from which the carbonate of the shell was obtained, and is sensitive to temperature changes as small as 20 C. The technique has been used to detect seasonal variations in shellfish collecting (Killingley, 1981; Shackleton, 1973), and could also be used to detect the water temperature variations of Ninos, assuming that midden shells with intact edges are available. If Wilson's suggestion (1981, p. 113) that shellfish were killed by Ninos is correct, then midden shells should exhibit only small


52 temperature variations. If shellfish were used as an emergency food supply during Ninos, as I have suggested, then an isotopic analysis of shell edges in middens should show that a significant proportion of the shellfish were collected from high temperature waters. CONCLUSIONS While the relation of Ninos to the development of cultural complex it} on the Peruvian coast during the Cotton Preceramic is a limited problem, both spatially and temporally, it has wider implications for the investigation of cultural adaptations to episodic events. Archeologists have been reluctant to deal with such situations, partly because it is difficult to detect most short-term events in the archeological record. There is probably also a tendency to ignore or minimize momentary events when dealing with hundreds and thousands of years of history. It has become increasingly evident, however, that episodic extreme natural events did influence cultural sequence in certain areas and may have been important elements of prehistoric adaptational systems. The role of volcanism in human ecology, for example, is the focus of a recently published collection of papers (Sheets and Grayson, 1979). The particular advantage of the Peruvian coast for the investigation of cultural response to natural hazards in prehistory is the periodicity of the Nino and the latitudinal variation of its effects. Hypotheses concerning possible relations between Ninos and cultural systems can be tested by comparing variability in both sets of data. It has been suggested before that Ninos may have had an important role in shaping preceramic cultural developments on the Peruvian coast (Osborn, 1977; Wilson, 1981; Yesner, 1980). The application of natural


53 hazards theory emphasizes the fact that cultural systems and the archeo logical remains they leave behind are expressions of the accumulated activities of groups of individuals who cope with natural events one way or another, sometimes effectively. The selection of methods of adjusting to natural hazards depends on the characteristics of the type of hazard involved and on the cultural context within which the response is made. Also relevant is the tendency of people to discount the potential effects of hazards that may happen only once during their lifetimes. If the hazard occurs frequently or is relatively minor in intensity or duration, responses tend to be limited to the individual or household and relate more to everyday activities. If the hazard occurs less often but still threatens the security of the system, responses tend to occur at the group level, with an emphasis on centralized management and control to maintain and reinforce long-term responses. I have shown that the distribution of monumental architecture along the Peruvian coast during the Cotton Preceramic correlates generally with latitudinal variations in Nino frequency, intensity and duration. There is more monumental architecture in areas where great Ninos would have forced the people to practice agriculture for a time, to retain seed crops always, and perhaps to store trade goods. While correlation does not necessarily imply causation, I argue that a causal relationship does exist in this case. The hypothesis is also supported by the fact that there is relatively little midden at inland sites with monumental architecture, and accounts for the presence of extensive room complexes at certain sites.


The most important point made in this paper is not simply that Ninos influenced cultural developments on the Peruvian coast; it is that cultural systems are not black boxes. Instead, they are composed of individuals and groups whose propensities, such as the tendency to take opportunistic actions, must be taken into account when investigating those systems.


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NATURAL HAZARD 'RESEARCH WORKING PAPER SERIES Institute of Behavioral Science #6, Mail Code 482 University of Colorado, Boulder, Colorado 80309 The Natural Hazard Research Working Papers series is a timely method to present research in progress in the field of human adjustments to natural hazards. It is intended that these papers will be used as working documents by the group of scholars directly involved in hazard research as well as inform a larger circle of interested persons. Single copies of working papers cost $4.50 per copy. It is also possible to subscribe to the working paper series. A subscription entitles the subscriber to receive each new working paper as it comes off the press at the special discount rate of $3.00 per copy. The subscription itself costs, nothing; when a new working paper is sent to a subscriber it is accompanied by a bill for that volume. 1 The Human Ecology of Extreme Geophysical Events, Ian Burton, Robert W. Kates, and Gilbert F. White, 1968, 37 pp. 2 Annotated Bibliography on Snow and Ice Problems, E. C. Relph and S. B. Goodwillie, 1968, 16 pp. 3 Water Quality and the Hazard to Health: Placarding Public Beaches, J. M. Hewings, 1968, 74 pp. 4 A Selected Bibliography of Coastal Erosion, Protection and Related Human Activity in North America and the British Isles, J. K. Mitchell, 1968, 70 pp. 5 Differential Response to Stress in Natural and Social Environments: An Application of a Modified Rosenzweig Picture-Frustration Test, Mary Barker and Ian Burton, 1969, 22 pp. 6 Avoidance-Response to the Risk Environment, Stephen Galant and Ian Burton, 1969, 33 pp. 7 The Meaning of a Hazard--Application of the Semantic Differential, Stephen Golant and Ian Burton, 1969, 40 pp. 8 Probabilistic Approaches to Discrete Natural Events: A Review and Theoretical Discussion, Kenneth Hewitt, 1969, 40 pp. 9 Human Behavior Before the Disaster: A Selected Annotated Bibliography, Stephen Golant, 1969, 16 pp. 10 Losses from Natural Hazards, Clifford S. Russell, (reprinted in Land Economics), 1969, 27 pp. 11 A Pilot Survey of Global Natural Disasters of the Past Twenty Years, Research carried out and maps compiled by Lesley Sheehan, Paper pre pared by Kenneth Hewitt, 1969, 18 pp.


12 Technical Services for the Urban Floodplain Property Manager: Organiza tion of the Design Problem", Kenneth Cypra and George Peterson, 1969, 25 pp. 13 Perception and Awareness of Air Pollution in Toronto, Andris Au1iciems and Ian Burton, 1970, 33 pp. 14 Natural Hazard in Human Ecolo ical Pers ective: H otheses and Models, Robert W. Kates reprinted in Economic Geography, July 1971 1970, 33 pp. 15 Some Theoretical As ects of Attitudes and Perce tion, Myra Schiff reprinted in Perce tions and Attitudes in Resources Mana ement, W. R. D. Sewell and Ian Burton, eds. 1970, 22 pp. 16 Suggestions for Comparative Field Observations on Natural Hazards, Revised Edition, October 20, 1970, 31 pp. 17 Economic Analysis of Natural Hazards: A Preliminary Study of Adjustment to Earthquakes and Their Costs, Tapan Mukerjee, 1971, 37 pp. 18 Human Adjustment to Cyclone Hazards: A Case Study of Char Jabbar, M. Aminul Islam, 1971, 60 pp. 19 Human Adjustment to Agricultural Drought in Tanzania: Pilot Investigations, L. Berry, T. Hankins, R. W. Kates, L. Maki, and P. Porter, 1971, 69 pp. 20 The New Zealand Earthquake and War Damage Commission--A Study of a National Natural Hazard Insurance Scheme, Timothy O'Riordan, 1971, 44 pp. 21 Notes on Insurance Against Loss from Natural Hazards, Christopher K. Vaughan, 1971, 51 pp. 22 Annotated Bibliography on Natural Hazards, Anita Cochran, 1972, 90 pp. 23 Human Impact of the Managua Earthquake Disaster, R. W. Kates, J. E. Haas, D. J. Amaral, R. A. Olson, R. Ramos, and R. Olson, 1973, 51 pp. 24 Drought Compensation Payments in Israel, Dan Varden, 1973, 25 pp. 25 Social Science Perspectives on the Coming San Francisco Earthquake-Economic Impact, Prediction, and Construction, H. Cochrane, J. E. Haas, M. Bowden and R. Kates, 1974, 81 pp. 26 Global Trends in Natural Disasters, 1947-1973, Judith Dworkin, 1974, 16 pp. 27 The Consequences of Large-Scale Evacuation Following Disaster: The Darwin, Australia Cyclone Disaster of December 25, 1974, J. E. Haas, H. C. Cochrane, and D. G. Eddy, 1976, 67 pp.


28 Toward an Evaluation of Policy Alternatives Governing Hazard-Zone Land Uses, E. J. Baker, 1976, 73 pp. 29 Flood Insurance and Community Planning, N. Baumann and R. Emmer, 1976, 83 pp. 30 An Overview of Drought in Kenya: Natural Hazards Research Paradigm, B. Wisner, 1976, 74 pp. 31 Warning for Flash Floods in Boulder, Colorado, Thomas E. Downing, 1977, 80 pp. 32 What People Did During the Big Thompson Flood, Eve C. Gruntfest, 1977, 62 pp. 33 Natural Hazard Response and Planning in Tropical Queensland, John Oliver, 1978, 63 pp. 34 Human Response to Hurricanes in Texas--Two Studies, Sally Davenport, 1978, 55 pp. 35 Hazard Mitigation Behavior of Urban Flood Plain Residents, Marvin Waterstone, 1978, 60 pp. 36 Locus of Control, Repression-Sensitization and Perception of Earthquake Hazard, Paul Simpson-Housley, 1978, 45 pp. 37 Vulnerability to a Natural Hazard: Geomorphic, Technological, and Social Change at Chiswell, Dorset, James Lewis, 1979, 39 pp. 38 Archeological Studies of Disaster: Their Range and Value, Payson D. Sheets, 1980, 35 pp. 39 Effects of a Natural Disaster on Local Mortgage Markets: The Pearl River Flood in Jackson, Mississippi April 1979, Dan R. Anderson and Maurice Weinrobe, 1980, 48 pp. 40 Our Usual Landslide: Ubiquitous Hazard and Socioeconomic Causes of Natural Disaster in Indonesia, Susan E. Jeffery, 1981, 63 pp. 41 Mass Media Operations in a Quick-onset Natural Disaster: Hurricane David in Dominica, Everett Rogers and Rahul Sood, 1981, 55 pp. 42 Notices, Watches, and Warnings: An Appraisal of the USGS's Warning System with a Case Study from Kodiak, Alaska, Thomas F. Saarinen and Harold J. McPherson, 1981, 90 pp. 43 Emergency Response to Mount St. Helens' Eruption: March 20-April 10, 1980. J. H. Sorensen, 1981, 70 pp. 44 Agroclimatic Hazard Perception, Prediction and Risk-Avoidance Strategies in Lesotho. Gene C. Wilken, 1982, 76 pp.


45 Trends and Developments in Global Natural Disasters, 1947 to 1981, Stephen A. Thompson, 1982, 3Q pp. 46 Emergency Planning Implications of Local Governments' Responses to Mount St. Helens, Jack D. Kartez, 1982, 29 pp. 47 Disseminating Disaster-Related Information to Public and Private Users, Claire 8. Rubin, 32 pp.