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1.
The relationship between environmental variation and subsistence practices is a central point of discussion in much Oceanic archaeology. While human predation can significantly reduce prey populations, environmental variation also contributes to reductions in prey abundance, possibly leading to increased human competition and resource scarcity. At the Natia Beach site, Nacula Island, Fiji, geoarchaeological evidence suggests that coastal progradation began soon after initial occupation of the coastal plain. Additionally, at approximately 650 BP a marked increase in clay and silt deposition occurred. Changes in coastal geomorphology may be explained by landscape response to regional Mid-Holocene sea level fall combined with human induced soil erosion due to upland settlement. Smaller scale environmental changes associated with climate variability may have also played a role. Additionally, landscape change appears to have had a measurable impact on local nearshore mollusks that are sensitive to high levels of water turbidity. Minor evidence of human exploitation is observable in this shellfish assemblage, although changes in predation pressure may have allowed shellfish populations to recover. Increased ceramic diversity and fortified settlements also appear at approximately 650 BP on Nacula and other parts of Fiji. The suite of changes at Natia may be explained by processes of regional and local environmental changes, and human adaptation in terms of subsistence, spatial organization, and competition.  相似文献   

2.
We use measurements of more than 11,000 marine shells from 41 archaeological components to construct a 10,000 year record of human impacts on ancient mussel and abalone stocks on San Miguel Island, California. General reductions in the mean size of mussel and abalone shells gathered through time are attributed to growing human population and predation pressure. Based on comparison with historically documented changes in shellfish communities caused by the local extinction of sea otters in the 19th century, changes in mean shell size and the abundance of other shellfish species may have been facilitated by Native American predation on sea otters as early as 7500 years ago. Despite having measurable impacts on local ecosystems, Native Americans on San Miguel harvested huge quantities of shellfish throughout the Holocene. Such long-term harvests appear to have been sustained by an early emphasis on fishing at lower trophic levels, by periodically shifting village locations, and by intensifying the use of finfish and sea mammals through time. This pattern of “fishing up the food web” contrasts with many modern fisheries, suggesting that the study of ancient fisheries can help us better manage our own endangered coastal ecosystems.  相似文献   

3.
The global blitzkrieg hypothesis explains differential rates of megafaunal extinction between the world's landmasses in the late Quaternary based on a proposed leap in predation efficiency enjoyed by colonising societies. It is characterised by appealing simplicity. Selective over hunting, facilitated by naiveté to human predation, produced rapid mass extinctions of large animals wherever subsistence societies colonised new landmasses. Taken at face value the circumstantial case for blitzkrieg is compelling and despite a paucity of direct evidence it has gained considerable support. Our review of the model suggests that it overlooks much contradictory data and rests on simplistic interpretations of complex biogeographicat and anthropological phenomena. These interpretations and assumptions do not account for major differences between the biotas, ecologies and human cultures of the landmasses involved. The assertion that responses of remote island species to human predation provide realistic models for those of continental taxa is poorly founded, exaggerating the likely predation efficiency of humans colonising continents. An absence of terrestrial predators over evolutionarily significant periods, together with restricted ranges and small populations, renders island faunas uniquely vulnerable to invaders. The argument, that climate cannot explain these phenomena because previous Glacial Maxima did not cause comparable extinctions, presupposes that their local effects were at least as severe as those of the Last Glacial Maximum. This has yet to be demonstrated and at most it would indirectly support a role for anthropogenic influence, not overkill per se. Overlooked or underplayed are the influences of translocated and other invading species. Similarly, differences in the origins, technologies and traditions of colonising human societies are rarely considered. These factors strongly impact on the predation efficiency, density and range of human populations, critically affecting the outcomes of predator-prey modeling. When a fuller constellation of influences and constraints is considered it is reasonable to posit that rapid mass extinction through selective human predation may largely describe megafaunal extinctions on remote islands, but the argument is not convincing for continents. This is especially so regarding Australia. Because even the largest Australian species were prey to endemic carnivores, their responses to human predation would not have been comparable to those of oceanic island species. No kill-sites or specialized big-game hunting/butchering tools are known and, on the basis of ethnographic and archaeological data, it is probable that predation efficiency, population density and range of the first Australians were insufficient to effect rapid mass extinction. Chronologies of human arrival and the disappearance of megafauna remain poor, but the most recent estimates for human-megafaunal coexistence in Australia range from 10,000 to 43,000 years. Although human predation may have been a contributing factor in megafaunal extinctions, rapid overkill is unlikely to describe the actual mechanism in most instances. The role of human predation and its significance relative to competing factors, human and otherwise, varied considerably between landmasses, as did the speeds with which extinctions occurred. Blitzkrieg and other mono-factorial models are heuristically valuable devices, but a growing body of evidence suggests that extinction can rarely, if ever, be attributed to a single cause.  相似文献   

4.
Resource intensification models that have been posited for prehistoric California predict decreases in foraging efficiency during the late Holocene, Using implications of the fine-grained prey model of optimal foraging theory, I derive an index of the efficiency of vertebrate prey choice from the relative abundances of large- and small-sized prey items. I then test the intensification models with late Holocene mammalian faunas from San Francisco Bay shellmounds. Dramatic linear decreases in the relalive frequency of artiodactyls compared to the smaller sea otters (Enhydra lutris) throughout the occupational histories of particular localities strongly support the resource intensification models. The declines in artiodactyl abundances are not correlated with late Holocene climatic indices developed for this region, with changes in the seasonal use of shellmounds, or with technological innovations. An intra- and interregionally consistent pattern in declining abundances of large mammals in environmentally distinct regions throughout California suggests that resource depression driven by human predators may be the single most important cause of the declines. These patterns have far-reaching implications concerning the long-term human role in structuring prehistoric ecosystems.  相似文献   

5.
Remains of black grouse, Lyrurus tetrix, were recovered from an archaeological excavation of the site of a golden eagle, Aquila chrysaetos, eyrie. It has been suggested that bird remains from human predation can be distinguished from those due to avian predation, because humans leave few of the distal bones (tibiotarsus, carpometacarpus). In this case, the eagle also left few of these bones; it is suggested that the distinction is one which may allow owl prey to be distinguished, but human and raptor prey are indistinguishable by that criterion.  相似文献   

6.
Behavioral depression is a decline in prey availability because of enhanced alert response, movement away from areas, increased social behavior, and other responses to predators. This form of resource depression is an alternative hypothesis to be contrasted to over-exploitation that potentially explains a decrease in hunting efficiency over time should the zooarchaeologist observe a decline in the relative abundance of remains of high-rank prey. Gregarious ungulates, such as many North American cervids, may exhibit such behavioral responses under predation. The white-tailed deer (Odocoileus virginianus), one of the most common high-rank prey animals from Holocene archaeological sites in eastern North America, is less gregarious, more r-selected, and exhibits greater home-range fidelity than other cervids. As a result, whitetails are less likely to exhibit behavioral depression than other North American ungulates, which may explain their common occurrence in Holocene archaeological faunas, such as that from the Eagle??s Ridge site in southeast Texas where resource depression appears to have occurred from 4,500 to 1,500?years ago. The behavioral ecology of ungulate species should be considered on a case-by-case basis to develop testable hypotheses about prehistoric human predation.  相似文献   

7.
This actualistic study examines the taphonomic signatures of modern free-ranging mountain lions (Felis concolor) on prey skeletal remains left at kill sites and digested bone fragments in the lions’ scats. Conducted in western Texas and southeastern New Mexico (U.S.A.), the study and its outcomes are relevant to models of carcass persistence and scavenging opportunities on ancient landscapes. Mountain lions in the study area ingested disproportionate quantities of bone from very young prey. This tendency holds true irrespective of prey body size. The results meanwhile confirm a relatively mild pattern of damage to adult deer carcasses. Digestive erosion of the surfaces of bones that passed through the gut was relatively severe, but many of these bone and tooth specimens retained identifiable features. It is clear that the mountain lions quickly remove the carcasses of very young prey from the pool of potentially scavenge-able resources. The non-linear relation between bone destruction from feeding by the cats and the skeletal maturity of prey also has consequences for prey mortality patterns, specifically a bias against the representation of very young individuals. This effect is not sufficient, however, to produce a global bias to prime-adult prey because older juveniles are much less affected.  相似文献   

8.
Because of its diverse geological formations, climates, and soils, Iran is home to outstanding biodiversity. National conservation started in Iran over fifty years ago and today nearly 10 percent of the country is protected. However, biodiversity in Iran is threatened, with about 100 species of vertebrate fauna vulnerable or endangered. Increased population and human activity, climate change, drought, desertification, agriculture, poaching, and economic sanctions have helped create this crisis. Many of these causes can be mitigated through better planning, sustainable policies, and increased civil society and local engagement. Promoting awareness about the impacts of human practices will also be important for the long-term sustainability of Iran’s ecosystems. Iranian conservation NGOs have already taken an active role in preserving biodiversity.  相似文献   

9.
Abstract

California's Channel Islands currently have around 150,000 breeding seals and sea lions (pinnipeds). Driven to near extinction by 20th-century exploitation, many pinniped populations have recovered dramatically under federal and state management and continue to expand in number and distribution. Some of these pinniped populations are damaging or destroying coastal archaeological sites as they establish new breeding and haul-out areas—places occupied between periods of foraging activity—on upland landforms. We use archaeological excavations from a prehistoric village on San Miguel Island to illustrate the adverse effects pinnipeds can have on archaeological sites. Estimates based on excavations at Otter Point suggest that in one year nearly 10,000 kg of shellfish remains, 840,000 animal bones, and 1700 formal artifacts were lost to erosion caused by the activities of seals and sea lions. Our study documents potential conflicts between natural and cultural resource management suggesting the need for collaborative efforts between archaeologists and biologists to balance the conservation of both resources.  相似文献   

10.
Recent archaeological research has fundamentally altered our understanding of the scope of past human impacts on nondomesticated animal populations. Predictions derived from foraging theory concerning the abundance histories of high-return human prey and diet breadth have been met in many parts of the world. People are known to have introduced a broad variety of nondomesticated animals, from sponges to agoutis and rats, to a remarkably broad set of contexts, in turn causing a wide variety of secondary impacts. By increasing the incidence of fire, human colonists have in some cases transformed the nature of the vegetation on the colonized landscape, in turn dramatically affecting animal populations on those landscapes. In island settings, these triple threats--predation, biotic introductions, and vegetation alteration--routinely led to extinctions but there is no archaeological evidence that small-scale societies caused extinction by predation alone on islands or continents. Indeed, the recent history of this famous argument suggests that it is better seen as a statement of faith about the past rather than as an appeal to reason. Perhaps most importantly, our burgeoning knowledge of past human impacts on animals has important implications for the conservation biology of the future.  相似文献   

11.
Temporally and spatially discontinuous pulses of heavy prehistoric exploitation of red abalone (Haliotis rufescens) have been documented along the southern and central California coast. This article examines the very late (post-950 cal BP) appearance of numerous red abalone processing sites on the Monterey Peninsula in central California. We test three prominent explanations offered for the sudden onset of red abalone processing sites: trophic cascades resulting from human predation on sea otters, logistical foraging by inland residents, and changes in sea surface temperature. A trophic cascade appears to have occurred but does not fully explain the nature or timing of the phenomenon in the region.  相似文献   

12.
Resource depression is often assumed to result from the over-exploitation of a prey species leading to declines in its population, and therefore availability, to human hunters. However, two other forms of resource depression are noted in the ecological literature: behavioral and micro-habitat depression. Data presented in this paper demonstrate resource depression of cormorants (Phalacrocorax spp.), a coastally breeding and semi-pelagic bird genus, at a coastal site in northern California. Citing modern cormorant behavior and a lack of evidence for intensive rookery exploitation, it is argued that the observed resource depression resulted from changes in cormorant behavior that decreased encounter rates for human hunters. Such behavioral depression is cited as a buffer to the extirpation of prey in mainland settings.  相似文献   

13.
This article is about the politics of wildlife management in Botswana. The existing literature on the origins of wildlife conservation in Africa has portrayed the formation of protected areas as an imposition of colonial state authorities. Preservationist policies are usually cast as the product of European conservationist ideas, and related notions of the ‘wilderness’ value of African landscapes. Many recent studies have emphasized the negative effects of such ideas and policies in a colonial context: they have drawn attention to the way in which they devalued local African ideas, undermined local management strategies, and criminalized access to important economic and cultural resources. The case discussed here, however, suggests that this interpretation needs closer scrutiny: the meaning and impact of global ideas and policies of wildlife conservation depends on how they are localized in particular places. The key actors in the foundation of Botswana's Okavango/Moremi National Park in the 1960s were not state officials but local BaTawana chiefs and a network of hunters and adventurers turned conservationists. The initiative was conceived as a means of protecting wildlife from the depredations of illegal South African hunting parties and ensuring future local use, and was initially opposed by the colonial state. The article discusses why Okavango/Moremi was an exception, and why the initial coalition of African and local settler interests came to see preservationist policies as being in their interest.  相似文献   

14.
Explanatory frameworks relating to the appearance of shell mounds and the exploitation of molluscs (particularly the sand/mudflat bivalve Anadara granosa) during the late Holocene have tended to emphasise stasis and continuity. Very few analyses have adequately investigated the intensity of human predation during the mound period and the potential effects on the particular prey species. To this end, the biological and ecological characteristics of A. granosa, the dominant molluscan species for much of the known period of occupation in the region, are considered in detail, in combination with assessing the potential for human impact through predation via the measurement of 9106 A. granosa valves from three shell mounds. In explaining long-term economic change in this region of northern Australia, the focus has been placed on the analysis of relative changes and trends through time in prehistoric resource exploitation.  相似文献   

15.
This paper examines the ways in which Tanzanian conservation authorities utilise biodiversity “extinction narratives” in order to legitimise the use of violence in redrawing protected areas’ boundaries. Militarisation and violence in conservation have often been associated with the “war on poaching”. Drawing on the history of conservation and violence in Tanzania, and using an empirical case from Loliondo, the paper suggests that violence in conservation may be legitimised when based on extinction narratives and a claim that more exclusive spaces are urgently needed to protect biodiversity. It argues that the emerging militarisation and use of violence in Tanzania can be associated with both global biodiversity extinction and local neo-Malthusian narratives, which recently have regained predominance. When combined with “othering” of groups of pastoralists by portraying them as foreign “invaders”, such associations legitimise extensions of state control over contested land by any means available, including violence.  相似文献   

16.
The maritime fur trade (1785–1840s) led to the local extinction of sea otters (Enhydra lutris) in many parts of the northeast Pacific. On the basis of studies of extant sea otter populations, it has been established that they have a disproportionate effect on nearshore ecosystems by limiting sea urchin abundance and facilitating the establishment of nearshore kelp forests; in the absence of sea otters, a local reduction in kelp-derived carbon is therefore expected. We measured the isotopic composition (δ13C and δ15N) of rockfish (Sebastes spp.) bone collagen from late Holocene archaeological sites in southern Haida Gwaii, BC, Canada, using δ13C as a proxy for kelp-derived carbon in the diet and δ15N as a proxy for trophic position. We observed significant spatial variability in rockfish kelp-derived carbon (δ13C), but not trophic level (δ15N). Kelp-derived carbon varied largely as a function of site characteristics (wave exposure), suggesting that local oceanographic conditions are important factors with respect to consumer tissue isotopic compositions. Kelp-derived carbon decreased in post-European contact rockfish relative to pre-European contact rockfish, likely as a result of the reduction of kelp forests associated with the local extirpation of sea otters. Although we detected a reduction in kelp-derived carbon in rockfish diets, we found no shift in trophic level at sites occupied following the maritime fur trade. This implies a shift in local ecosystems, and particularly in carbon sources, following the maritime fur trade, likely due to a trophic cascade resulting from the local extirpation of sea otters. Stability in rockfish trophic levels, however, implies that rockfish continued to feed at similar trophic levels, consuming prey with similar nitrogen isotopic compositions.  相似文献   

17.
Carnivory, Coevolution, and the Geographic Spread of the Genus Homo   总被引:1,自引:0,他引:1  
This review traces the colonization of Eurasia by hominids some 1,700,000 years ago and their subsequent evolution there to 10,000 years ago from a carnivorous perspective. Three zooarchaeological trends reflect important shifts in hominid adaptations over this great time span: (1) increasing predation on large, hoofed animals that culminated in prime-adult–biased hunting, a predator–prey relationship that distinguishes humans from all other large predators and is a product of coevolution with them; (2) greater diet breadth and range of foraging substrates exploited in response to increasing human population densities, as revealed by small-game use; and (3) increased efficiency in food capture, processing, and energy retention through technology, and the eventual expansion of technology into social (symbolic) realms of behavior. Niche boundary shifts, examined here in eight dimensions, tend to cluster at 500 thousand years ago (KYA), at 250 KYA, and several in rapid succession between 50 and 10 KYA. Most of these shifts appear to be consequences of competitive interaction, because high-quality, protein-rich resources were involved. Many of the boundary shifts precede major radiations in the equipment devoted to animal exploitation. With a decline in trophic level after 45 KYA, demographic increase irreversibly altered the conditions of natural selection on human societies, from a largely interspecific competitive forum to one increasingly defined by intraspecific pressures. Regionalization of Upper Paleolithic artifact styles is among the many symptoms of this process.  相似文献   

18.
The Canadian Government has committed to establishing a national network of Marine Protected Areas. Progress in the Salish Sea (Strait of Georgia) of British Columbia has been slow. Opposition by First Nations is a factor as these protected areas have the potential to impact on Aboriginal rights. This case study with the Hul’qumi’num First Nations examines their approaches to marine conservation and their perspectives on “no‐take zones” as a component of marine conservation. The study used a variety of community engagement procedures including relationship building, hiring of a Hul’qumi’num research assistant, conducting individual interviews, focus groups, and field surveys. Interviews were conducted with 41 participants contacted because of their knowledge and interest in marine resource use. The views reported provide a rich understanding of Hul’qumi’num attitudes, but cannot be generalised to the whole population. There was widespread support for efforts to involve local First Nations communities in the development of management plans for marine resources, and also for recognition of First Nation reliance on marine resources for food, social, and ceremonial needs and for economic development opportunities. The establishment of permanent no‐take zones was met with both opposition and support. The most highly endorsed statement about no‐take zones is one of principle—that they are a violation of Aboriginal rights. However, there was also strong agreement that permanent no‐take zones would help reduce over‐fishing. The National Marine Conservation Area program is in its infancy and it remains to be seen how the “strictly protected” zone of the legislation will be interpreted in relationship to Aboriginal harvesting practices. However it is clear that successful conservation will only occur with Aboriginal consent in many areas and there needs to be greater investment in understanding Aboriginal perspectives on marine conservation.  相似文献   

19.
Much research on nature conservation in war‐torn regions focuses on the destructive impact of violent conflict on protected areas, and argues that transnational actors should step up their support for those areas to mitigate the risks that conflict poses to conservation efforts there. Overlooked are the effects transnational efforts have on wider conflict dynamics and structures of public authority in these regions. This article describes how transnational actors increasingly gained influence over the management of Virunga National Park in eastern Democratic Republic of Congo (DRC), and how these actors contributed to the militarization of conservation in Virunga. Most scholarly literature suggests that ‘green militarization’ contributes to the extension of state authority over territory and population, yet this is not the case in Virunga. Instead, the militarization of Virunga translates into practices of extra‐state territorialization, with the result that many in the local population perceive the park's management as a project of personalized governance and/or a ‘state within a state’. This article thus argues that it is important to depart from an a priori notion of the ‘state’ when considering the nexus of conservation practices and territorialization, and to analyse this intersection through the lens of public authority instead.  相似文献   

20.
ABSTRACT

Archaeological evidence of shellfish exploitation along the coast of Sahul (Pleistocene Australia-New Guinea) points to an apparent paradox. While the continental record as a whole suggests that human populations were very low from initial colonization through early Holocene, coastal and peri-coastal sites dating to that time are dominated by small, low-ranked, littoral taxa to the near-complete exclusion of large, higher ranked, sub-littoral species, precisely the opposite of theory-based expectations, if human populations and predation rates were indeed as low as other data suggest. We present a model of shellfish exploitation combining information on species utility, transport considerations, and prey life-history that might account for this apparent mismatch, and then assess it with ethnographic and archaeological data. Findings suggest either that high-ranked taxa were uncommon along the Pleistocene coastlines of Sahul, or that abundant and commonly taken high-ranked prey are under-represented in middens relative to their role in human diets largely as a function of human processing and transport practices. If the latter reading is correct, archaeological evidence of early shellfishing may be mainly the product of subsistence activities by children and their mothers.  相似文献   

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