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Between [approximately equal to] 5,800 and 3,600 cal B.P. the biggest architectural monuments and largest settlements in the Western Hemisphere flourished in the Supe Valley and adjacent desert drainages of the arid Peruvian coast. Intensive net fishing, irrigated orchards, and fields of cotton with scant comestibles successfully sustained centuries of increasingly complex societies that did not use ceramics or loombased weaving. This unique socioeconomic adaptation was abruptly abandoned and gradually replaced by societies more reliant on food crops, pottery, and weaving. Here, we review evidence and arguments for a severe cycle of natural disasters-earthquakes, El Nino flooding, beach ridge formation, and sand dune incursion--at [approximately equal to] 3,800 B.P. and hypothesize that ensuing physical changes to marine and terrestrial environments contributed to the demise of early Supe settlements. El Nino | geoarchaeology | Preceramic collapse | Mid-Holocene

Previous research indicates that the Nanchoc Valley in northern Peru was an important locus of early and middle Holocene human settlement, and that between 9200 and 5500 [sup.14]C yr B.P. the valley inhabitants adopted major crop plants such as squash (Cucurbita moschata), peanuts (Arachis sp.), and cotton (Gossypium barbadense). We report here an examination of starch grains preserved in the calculus of human teeth from these sites that provides direct evidence for the early consumption of cultivated squash and peanuts along with two other major food plants not previously detected. Starch from the seeds of Phaseolus and Inga feuillei, the flesh of Cucurbita rnoschata fruits, and the nuts of Arachis was routinely present on numerous teeth that date to between 8210 and 6970 [sup.14]C yr B.P. Early plant diets appear to have been diverse and stable through time and were rich in cultivated foods typical of later Andean agriculture. Our data provide early archaeological evidence for Phaseolus beans and L feuillei, an important tree crop, and indicate that effective food production systems that contributed significant dietary inputs were present in the Nanchoc region by 8000 [sup.14]C yr B.P. Starch grain studies of dental remains document plants and edible parts of them not normally preserved in archaeological records and can assume primary roles as direct indicators of ancient human diets and agriculture. early diets | South America | food production

Recharge by mafic magma is established as a trigger of major explosive volcanic eruptions. However, recharge by silicic magma can also induce perched resident magma to erupt. The evidence of such recharge may be more cryptic than for mafic recharge and requires detailed petrologic and geochemical study to identify. We present a study of plagioclase petrology supported by other data that implicates silicic-silicic magma interaction during the eruption and evolution of the A.D. 1600 eruption of Huaynaputina, one of the largest historical eruptions. Recharge by silicic magma is probably more common than recognized and should be considered an important eruption trigger. Keywords: silicic recharge, crystal mush, magma mingling, eruption trigger, Huaynaputina.

New rhynchonelliformean brachiopods are documented from Upper Cambrian and Tremadoc beds of the Cordillera Oriental and Puna regions, which are representative of the initial radiation of Plectorthoidea on the Andean (South American) shelves of Gondwana. Protorthisina n. gen., so far the oldest known representative of the family Euorthisinidae, and Lesserorthis n. gen. (Euorthisinidae?) are described, as well as the new species Euorthisina? nazarenensis, Kvania mergli, Kvania lariensis, Kvania azulpampensis (with two subspecies), Kvania? primigenia, and Nanorthis calderensis (with two subspecies). Protorthisina, Kvania, and Nanorthis form a stratigraphically continuous series of species displaying well-defined evolutionary trends involving size, shell ornament, and internal features. In the cardinalia, a transition from a V-shaped septalium (typical of Protorthisina) through almost parallel brachiophore plates (typical of Kvania) to the orthoid notothyrial platform of Nanorthis is documented. The species Nanorthis purmamarcaensis Benedetto and 'Nanorthis' grandis (Harrington) are considered as the end members of the lineage. The heterochronic (peramorphic) origin of this trend is supported by ontogenetic evidence from species of Kvania and Nanorthis calderensis. The origin of the 'plectorthoid' cardinalia of Kvania from a euorthisinid configuration present in the stem group, followed by the appearance of a orthoid-like configuration in Nanorthis, pose an intricate systematic problem. The preliminary phylogenetic analysis of the northwestern basin taxa shows that the Upper Cambrian Protorthisina simplex n. gen. and sp. is the stem group of both the nanorthid and euorthisinid clades. On the basis of the new evidence, the genus Nanorthis is removed from the Orthoidea to the Plectorthoidea, and the diagnosis of the families Euorthisinidae and Nanorthidae are revised.

Cenozoic marine deposits of forearc basins in southern Peru contain a molluscan fauna that includes 15 species of turritelline gastropods. Twelve species were previously known; ten from northern Peru or Chile and two species solely from southern Peru. Three new fossil species are described: Turritella riverae, Turritella cruzadoi, and Turritella salasi. Six species of turritellines with crenulated primary spirals, a distinctive spiral ontogeny, and which are mostly endemic to Peru and Chile, are assigned to Incatella n. gen., including L cingulata (Sowerby, 1825), I. cingulatiformis (Moricke, 1896), I. chilensis (Sowerby, 1846), I. leptogramma (Philippi, 1887), I. hupei Nielsen, new name (=Turritella affinis Hupe, 1854), and I. trilirata (Philippi, 1887). Most Paleogene taxa range from northern to southern Peru, while most Neogene taxa, including all species of Incatella, range from Peru to Chile. This biogeographic asymmetry is attributed to a series of biotic events (e.g., extinctions, immigrations) impelled by global oceanographic changes acting locally in a regime of coastal upwelling.

One of the most important developments in the existence of human society was the successful shift from a subsistence economy based on foraging to one primarily based on food production derived from cultivated plants and domesticated animals. The shift to plant food production occurred in only a few independent centers around the world and involved a commitment to increased sedentism and social interaction and to permanent agricultural fields and canals. One center was Peru, where early civilization and food production were beginning to develop by at least 4,500 years ago. New archeological evidence points to 5,400- and possible 6,700-year-old small-scale gravity canals in a circumscribed valley of the western Andean foothills in northern Peru that are associated with farming on low terrace benches at the foot of alluvial fans in areas where the canals are drawn from hydraulically manageable small lateral streams. This evidence reveals early environmental manipulation and incipient food production in an artificially created wet agroecosystem rather than simply the intensive harvesting or gardening of plants in moist natural areas. This finding is different from previously conceived notions, which expected early canals in lower-elevated, broad coastal valleys. The evidence also points to communal organization of labor to construct and maintain the canals and to the scheduling of daily activities beyond individual households. The development of early organized irrigation farming was combined with a hunting and gathering economy to support an increase in the local population size. agriculture | Peru

Over the last 15 years there have been dramatic shifts in the consensus over how best to cope with natural hazards in economically developing regions such as South America. One very positive outcome of the United Nations sponsored International Decade for Natural Disaster Reduction (IDNDR 1990-2000) has been that there is now greater interchange between the work of earth scientists examining the processes and mechanics of hazard occurrence and impact, and social scientists exploring the causes of human vulnerability to hazard--and thereby disaster. This paper traces the development of this new understanding with reference to earthquakes and volcanic eruptions in Peru, one of the most hazardous countries in South America. Particular focus is placed on the excellent progress currently being made by scientists in better understanding the physical dimensions of natural hazard exposure, and the ground-breaking work by social scientists in promoting new approaches to understanding and mitigating human vulnerability to disaster. The paper concludes by emphasizing the need to build on this research to produce more inclusive, incultured and unified strategies of disaster mitigation at the local, national and international levels. KEY WORDS: Peru, Latin America, earthquake, volcano, tsunami, vulnerability, response

Morton L. Isler (1,4) Jose Alvarez Alonso (2) Phyllis R. Isler (1) Bret M. Whitney (3) ABSTRACT.--Ornithological studies undertaken in certain sandy soil habitats of lowland northeastern Peru uncovered a [...]

A new species of antwren (Myrmotherula fjeldsaai) closely related to Myrmotherula haematonota is described from the lower tropical zone of eastern Ecuador and immediately adjacent Peru. It primarily differs from M. h. haematonota by its brown instead of red back in both sexes. New distributional data for nominate M. h. haematonota shows that it meets the new species north of the Rio Maranon, between the Rios Napo and Pastaza, with no apparently significant physical barrier between them., Two species of 'stipple-throated' antwrens, Ornate Antwren (Myrmotherula ornata) and White-eyed Antwren (Myrmotherula leucophthalma) show distinct geographical variation in back color. In some populations of each species the back is [...]

Strict coevolution requires that interactions among organisms be species-specific. We assessed the relative roles of host- and habitat-specificity in determining the match between a genus of myrmecophytic trees and a guild of obligate plant-ants in the moist tropical forests of Madre de Dios, Peru. Four locally coexisting but habitat-restricted Cecropia species were cultivated in screen tents until all plants had developed myrmecophytic traits. Saplings were then placed within replicate blocks of each of two habitat types: riversides and small forest light gaps. Colonization events were recorded every 3 d between June and August of 1992, and queens were later removed from stem internodes for identification and brood censuses. A similar experiment, conducted in September through November of 1993, included just two species of Cecropia hosts. Effects of host species and habitat on queen colonization rates were evaluated by log-likelihood goodness-of-fit tests and contingency table tests. For three ant species, we also conducted queen preference experiments to compare queen behaviors across a range of host plants. Differences among ants in the extent of habitat-specificity vs. host-specificity provide evidence for multiple evolutionary routes to obligate association with Cecropia. Habitat-specificity exceeded host-specificity in Azteca ovaticeps (Dolichoderinae), for which queen preference experiments revealed no significant discrimination among hosts. This extreme riverside specialist is thought to have descended from generalist live-stem nesters in second-growth habitats. In Azteca australis; host-specificity was strong, and in this species only, directed toward hosts where brood production was most successful. Conflicting habitat associations in the two experiments indicated the weakness or absence of a consistent habitat affiliation in Azteca australis and suggested that colonization frequencies were influenced instead by proximity to foundress sources. Close relatives of A. australis live in exposed carton nests, which may have been positioned ancestrally on key resource plants, e.g., those producing lipid- and amino-acid-rich pearl bodies. Pachycondyla luteola (Ponerinae) exhibited both strong habitat and host associations and may have undergone pair-wise coevolution with its forest-gap-dwelling primary host. Queens of Camponotus balzani (Formicinae), possibly a recent and secondary associate of Cecropia, were overrepresented in forest gap habitat but were host generalists, underrepresented only on a host with extremely small internodes. Apparently greater host-specificity in C. balzani at later stages of colony establishment may be due to differential post colonization mortality on the various hosts. Attack of ant queens by parasitoid wasps was strongly concentrated in the linear riverside habitat and weak to absent in the patchily distributed forest gap habitat. Due to lower rates of either parasitoid attack or other forms of queen mortality, Camponotus balzani experienced greater success in the forest gap habitat, where it was overrepresented in colonization experiments. Historical coincidences and preadaptations appear to have strongly influenced pairings between Cecropia species and their obligate plant-ants and account for much of the 'apparent' niche partitioning observed in the system. Species-specificity seems to be determined mainly by coincident habitat affiliations of ants and plants ('coordinated dispersal') and by preadapted capacities of ants to distinguish among host-plant species. Multiple mechanisms for species-specificity may be characteristic of relationships in which associates disperse separately from one another (i.e., show horizontal transmission). Our results are consistent with the view that coadaptation and co-cladogenesis are more likely in systems where dispersal of associates is tightly coupled. Key words: ant-plant; ants; Cecropia; coevolution; colonization; coordinated dispersal; ecological fitting; habitat-specificity; host-specificity; mutualism; parasitoid wasps; preadaptation., INTRODUCTION A key challenge of coevolutionary studies is to understand the ecological and evolutionary factors driving interacting species to undergo progressive bouts of reciprocal evolutionary change (Ehrlich and Raven 1964, [...]

For the tropical west coast of South America, where El Nino/Southern Oscillation (ENSO) is most pronounced, archaeological and associated paleontological deposits in northern Peru revealed a major climate change at about 5000 years before the present (yr B.P.). The data implied the presence of stable, warm tropical water as far south as 1 0 S during the early mid-Holocene (about 8000 to 5000 yr B.P.). These data suggest that ENSO did not occur for some millennia preceding 5000 yr B.P., when global and regional climate was warmer than today., ENSO is characterized by interannual climate variability in the Pacific basin and beyond and by elevated sea surface temperatures in the eastern Pacific near western South America. Analyses of pollen [...]

JOSE ALVAREZ ALONSO [1,3] BRET M. WHITNEY [2] ABSTRACT.--Zimmerius villarejoi (Mishana Tyrannulet) is the second novel species to be described in recent years from poorly drained, white sand varillal forest [...]

PAUL COOPMANS [1] NIELS KRABBE [2,3,4] ABSTRACT.--A new species of New World flycatcher in the genus Myiopagis (Aves, Tyrannidae, Elaeniinae is described from Andean submontane forest of eastern Ecuador and [...]

Cooperative foraging behavior is rarely observed in ground-walking birds. I report on observations of cooperative foraging behavior by Mountain Caracaras (Phalcoboenus megalopterus) in the puna region of Peru in September of 1995. On several occasions, three individuals (two adults and one immature) were observed working together to turn over large rocks to obtain prey from beneath. These cooperative foraging events are notable in that, unlike cooperative foraging behavior observed in other ground-walking birds, only one individual obtained prey from a given cooperative effort. The presence of the immature individual may be indicative of delayed dispersal, a behavior not previously described for this poorly known species., Cooperative foraging involves two or more individual organisms assisting one another in obtaining a food item. Among vertebrates, this behavior is well described in many social mammals (Macdonald 1983, Serfass [...]

Herbicide Refused for Coca Spraying The generals of the Administration's war on drugs are trying to figure out a way to conscript Eli Lilly and Company to help its cause. [...]