A model for wildfire prevention planning in game resources

The high incidence of hunting activity and forest fires in different ecosystems (particularly in Mediterranean ecosystems) requires a model, which allows for the comprehensive management of hunting resources and estimating the potential damage caused by this type of disturbance. This paper proposes a model for evaluating the socio-economic effects of forest fires on hunting. Its cornerstone lies in evaluating hunting resource availability for each ecosystem within its territorial mosaic. Each game management unit (GMU) is identified by vegetation structure and habitat type. It presents a novel approach in which the economic value of each game management unit is linked to potential forest fire damages. The effect a forest fire has on an entire ecosystem depends on the intensity of its flames. A sample study was undertaken in the province of Huelva in Andalusia (southern Spain). The socio-economic hunting vulnerability of the province of Huelva was 45,188,000€. The results obtained confirmed the need for an economic appraisal of non-forest products in the forest and other woodland areas. Geographic Information System increases the flexibility and simplicity of our methodology which permits immediate extrapolation to other agroforestry territories.     

Effects of Subsistence Hunting on Vertebrate Community Structure in Amazonian Forests

Abstract: Subsistence hunting affects vast tracts of tropical wilderness that otherwise remain structurally unaltered, yet distinguishing hunted from nonhunted tropical forests presents a difficult problem because this diffuse form of resource extraction leaves few visible signs of its occurrence. I used a standardized series of line-transect censuses conducted over a 10-year period to examine the effects of subsistence game harvest on the structure of vertebrate communities in 25 Amazonian forest sites subjected to varying levels of hunting pressure. Crude vertebrate biomass, which was highly correlated with hunting pressure, gradually declined from nearly 1200 kg km⁻² at nonhunted sites to less than 200 kg km⁻² at heavily hunted sites. Hunting had a negative effect on the total biomass and relative abundance of vertebrate species in different size classes at these forest sites, but it did not affect their overall density. In particular, persistent hunting markedly reduced the density of large-bodied game species (>5 kg), which contributed a large proportion of the overall community biomass at nonhunted sites (65–78%) and lightly hunted sites (55–71%). Nutrient-rich floodplain forests contained a consistently greater game biomass than nutrient-poor unflooded forests, once I controlled for the effects of hunting pressure. Conservative estimates of game yields indicate that as many as 23.5 million game vertebrates, equivalent to 89,224 tons of bushmeat with a market value of US$190.7 million, are consumed each year by the rural population of Brazilian Amazonia, which illustrates the enormous socioeconomic value of game resources in the region. My cross-site comparison documents the staggering effect of subsistence hunters on tropical forest vertebrate communities and highlights the importance of considering forest types and forest productivity in game management programs.     

Hunting, law enforcement, and African primate conservation

Abstract: Primates are regularly hunted for bushmeat in tropical forests, and systematic ecological monitoring can help determine the effect hunting has on these and other hunted species. Monitoring can also be used to inform law enforcement and managers of where hunting is concentrated. We evaluated the effects of law enforcement informed by monitoring data on density and spatial distribution of 8 monkey species in Taï National Park, Côte d’Ivoire. We conducted intensive surveys of monkeys and looked for signs of human activity throughout the park. We also gathered information on the activities of law‐enforcement personnel related to hunting and evaluated the relative effects of hunting, forest cover and proximity to rivers, and conservation effort on primate distribution and density. The effects of hunting on monkeys varied among species. Red colobus monkeys (Procolobus badius) were most affected and Campbell's monkeys (Cercopithecus campbelli) were least affected by hunting. Density of monkeys irrespective of species was up to 100 times higher near a research station and tourism site in the southwestern section of the park, where there is little hunting, than in the southeastern part of the park. The results of our monitoring guided law‐enforcement patrols toward zones with the most hunting activity. Such systematic coordination of ecological monitoring and law enforcement may be applicable at other sites.     

Trophy Hunting and Wildlife Conservation in Zambia

For wildlife conservation to succeed in developing countries, people who live in or near protected areas must receive benefits that offset the costs of their reduced access to natural resources. International trophy hunting is currently generating significant economic benefits for residents of game management areas in Zambia. This has been made possible through a revolving fund and an administrative program that direct revenues from trophy hunting to local wildlife management and community development projects. Benefits might be enhanced by better biological information for management, greater local participation in the allocation and operation of hunting concessions, and the promotion of ecological and ethical standards for trophy hunting. An international system of certification for trophy hunting operations could foster these improvements.     

Use of Historical Logging Patterns to Identify Disproportionately Logged Ecosystems within Temperate Rainforests of Southeastern Alaska

The forests of southeastern Alaska remain largely intact and contain a substantial proportion of Earth's remaining old‐growth temperate rainforest. Nonetheless, industrial‐scale logging has occurred since the 1950s within a relatively narrow range of forest types that has never been quantified at a regional scale. We analyzed historical patterns of logging from 1954 through 2004 and compared the relative rates of change among forest types, landform associations, and biogeographic provinces. We found a consistent pattern of disproportionate logging at multiple scales, including large‐tree stands and landscapes with contiguous productive old‐growth forests. The highest rates of change were among landform associations and biogeographic provinces that originally contained the largest concentrations of productive old growth (i.e., timber volume >46.6 m³/ha). Although only 11.9% of productive old‐growth forests have been logged region wide, large‐tree stands have been reduced by at least 28.1%, karst forests by 37%, and landscapes with the highest volume of contiguous old growth by 66.5%. Within some island biogeographic provinces, loss of rare forest types may place local viability of species dependent on old growth at risk of extirpation. Examination of historical patterns of change among ecological forest types can facilitate planning for conservation of biodiversity and sustainable use of forest resources. El Uso de Patrones Históricos de Tala para Identificar Ecosistemas Talados Desproporcionadamente en Bosques Lluviosos Templados del Sureste de Alaska Albert & Schoen 11‐839     

Lessons from Białowieża Forest on the history of protection and the world's first reintroduction of a large carnivore

Understanding how the relationships between large carnivores and humans have evolved and have been managed through centuries can provide relevant insights for wildlife conservation. The management history of many large carnivores has followed a similar pattern, from game reserved for nobility, to persecuted pests, to conservation targets. We reconstructed the history of brown bear (Ursus arctos) management in Bia?owie?a Forest (Poland and Belarus) based on a detailed survey of historical literature and Russian archives. From the end of the Middle Ages to the end of 18th century, the brown bear was considered “animalia superiora” (i.e., game exclusively reserved for nobility and protected by law). Bears, also a source of public entertainment, were not regarded as a threat. Effective measures to prevent damages to traditional forest beekeeping were already in practice. In the beginning of 19th century, new game‐management approaches allowed most forest officials to hunt bears, which became the primary target of hunters due to their valuable pelt. This, together with an effective anticarnivore policy enhanced by bounties, led to bear extirpation in 1879. Different approaches to scientific game management appeared (planned extermination of predators and hunting levels that would maintain stable populations), as did the first initiatives to protect bears from cruel treatment in captivity. Bear reintroduction in Bia?owie?a Forest began in 1937 and represented the world's first reintroduction of a large carnivore motivated by conservation goals. The outbreak of World War II spoiled what might have been a successful project; reproduction in the wild was documented for 8 years and bear presence for 13. Soft release of cubs born in captivity inside the forest but freely roaming with minimal human contact proved successful. Release of captive human‐habituated bears, feeding of these bears, and a lack of involvement of local communities were weaknesses of the project. Large carnivores are key components of ecosystem‐function restoration, and site‐specific histories provide important lessons in how to preserve them for the future.     

Anti-predation behaviour of red colobus monkeys in the presence of chimpanzees

Predator-prey interactions are usually regarded as evolutionary “arms races”, but evidence is still scarce. We examined whether the anti-predation strategies of red colobus monkeys (Procolobus badius) are adapted to the hunting strategies of chimpanzees (Pan troglodytes) in the Taï National Park, Ivory Coast. Taï chimpanzees search for red colobus groups, approach them silently and hunt co-operatively. Our playback experiments and observations of natural encounters revealed that red colobus hid higher up the trees in positions where exposure to the forest floor is minimal and became silent, when chimpanzees were close. They moved away silently through the canopy, when chimpanzees were still at some distance. However, if a group of diana monkeys was nearby in the latter situation, red colobus sought their presence even if they had to move towards the chimpanzees. Chimpanzees refrained from hunting associated red colobus groups, probably because diana monkeys are excellent sentinels for predators approaching over the forest floor. Thus several elements of both the predator's and the prey's strategies correspond to each other. Finally, we compared the interactions between the two species in Taï and in Gombe, Tanzania. We suggest that the difference in size ratio between the two species at the two sites and adaptation of hunting techniques and of escape modes to different forest structures can explain why Gombe red colobus attack chimpanzees while Taï red colobus try to escape. We conclude that predator-prey interactions can indeed lead to evolutionary arms races, with the specific form of co-adaptations depending on environmental factors.     

A meta‐analysis of functional group responses to forest recovery outside of the tropics

Both active and passive forest restoration schemes are used in degraded landscapes across the world to enhance biodiversity and ecosystem service provision. Restoration is increasingly also being implemented in biodiversity offset schemes as compensation for loss of natural habitat to anthropogenic development. This has raised concerns about the value of replacing old‐growth forest with plantations, motivating research on biodiversity recovery as forest stands age. Functional diversity is now advocated as a key metric for restoration success, yet it has received little analytical attention to date. We conducted a meta‐analysis of 90 studies that measured differences in species richness for functional groups of fungi, lichens, and beetles between old‐growth control and planted or secondary treatment forests in temperate, boreal, and Mediterranean regions. We identified functional‐group–specific relationships in the response of species richness to stand age after forest disturbance. Ectomycorrhizal fungi averaged 90 years for recovery to old‐growth values (between 45 years and unrecoverable at 95% prediction limits), and epiphytic lichens took 180 years to reach 90% of old‐growth values (between 140 years and never for recovery to old‐growth values at 95% prediction limits). Non‐saproxylic beetle richness, in contrast, decreased as stand age of broadleaved forests increased. The slow recovery by some functional groups essential to ecosystem functioning makes old‐growth forest an effectively irreplaceable biodiversity resource that should be exempt from biodiversity offsetting initiatives.     

Hunting for Sustainability in Tropical Secondary Forests

Abstract:  The interaction between land-use change and the sustainability of hunting is poorly understood but is critical for sustaining hunted vertebrate populations and a protein supply for the rural poor. We investigated sustainability of hunting in an Amazonian landscape mosaic, where a small human population had access to large areas of both primary and secondary forest. Harvestable production of mammals and birds was calculated from density estimates. We compared production with offtake from three villages and used catch-per-unit-effort as an independent measure of prey abundance. Most species were hunted unsustainably in primary forest, leading to local depletion of the largest primates and birds. The estimated sustainable supply of wild meat was higher for primary (39 kg · km⁻²· yr⁻¹) than secondary forest (22 kg · km⁻²· yr⁻¹) because four species were absent and three species at low abundance in secondary forests. Production of three disturbance-tolerant mammal species was 3 times higher in secondary than in primary forest, but hunting led to overexploitation of one species. Our data suggest that an average Amazonian smallholder would require ≥3.1 km² of secondary regrowth to ensure a sustainable harvest of forest vertebrates. We conclude that secondary forests can sustainably provide only 2% of the required protein intake of Amazonian smallholders and are unlikely to be sufficient for sustainable hunting in other tropical forest regions.     

Mechanized Logging, Market Hunting, and a Bank Loan in Congo

Financing for logging of tropical moist forests in the Republic of Congo is commonly sought in the form of loans from multilateral development banks. Pressure from nongovernmental conservation organizations and from within the banks themselves has resulted in their beginning to assess the environmental consequences of such loans. We conducted one of the first such assessments of an African Development Bank loan to a logging company. Geographic isolation, resulting transportation costs, and market demands have forced commercial loggers within the Sangha region of Congo to exploit only the most valuable timber. This form of timber extraction destroys an average of 6.8% of the canopy and thus, unlike clear cutting, was expected to have a minimal impact on wildlife populations. Line transect counts showed, however, that primate abundance was exceedingly low in logged forest. We believe this is not a direct consequence of canopy reduction, but results from the extremely intensive market hunting that coincides with timber surveying and extraction. Weapons and hunting camps were common, and logging company vehicles transported primates, duikers and other game daily. Wildlife laws of Congo are openly violated and they are not enforced. While market hunting is clearly facilitated and intensified by the presence of logging concessions, it is the Congo's highly urbanized population that provides the ever growing demand for meat, a demand not being met through animal husbandry. Thus, although selective logging in the absence of hunting may have only limited adverse effects on wildlife, when the two are combined the consequences are grave for the Sangha region's wildlife. Loans to logging companies from the African Development Bank should incorporate conditions for ensuring wildlife conservation.     

Environmental implications of tropical deforestation

SUMMARY

Forests are fundamental and vital components of the world ecosystems. The essential links between forest and man are now receiving renewed and urgent attention, and there is increasing awareness that the value of forests to life on Earth is beyond economic value, and should be above political considerations. Tropical forests, generally marked out by richness in species, are found in more than 80 countries and account for roughly one-third of the world's forest cover. They encompass a wide variety of forest types found under diverse environmental conditions — from lush, constantly wet rain forests to arid thorn woodlands. These forests have been estimated to cover about 1715 million hectares in Africa alone. They have provided habitats for wildlife and wood, fibre, food and many other products to generations of mankind and are invaluable genetic resources of plants. Rapid population growth has, however, resulted in increasing the pressure on these forests, with a consequent decline in their qualitative and quantitative values. Throughout the world, forest lands have been cleared extensively for agriculture, and deforestation continues today. In the tropics, 10–25 million ha are being lost each year, with Africa alone losing 4–5 million ha annually. It has been estimated that, at this rate, the remaining tropical forest would disappear in 60–80 years; thereby leading to catastrophic environmental changes. The serious impact of these changes on the environment and on human needs is awakening world attention, and alarming consequences have sometimes been suggested. This paper highlights the major causes of tropical deforestation and its environmental consequences. Possible efforts to arrest the unpleasant trend are discussed.     

Synergistic Effects of Subsistence Hunting and Habitat Fragmentation on Amazonian Forest Vertebrates

Abstract: Subsistence game hunting has profound negative effects on the species diversity, standing biomass, and size structure of vertebrate assemblages in Amazonian forests that otherwise remain largely undisturbed. These effects are likely to be considerably aggravated by forest fragmentation because fragments are more accessible to hunters, allow no (or very low rates of  ) recolonization from nonharvested source populations, and may provide a lower-quality resource base for the frugivore-granivore vertebrate fauna. I examined the likelihood of midsized to large-bodied bird and mammal populations persisting in Amazonian forest fragments of variable sizes whenever they continue to be harvested by subsistence hunters in the aftermath of isolation. I used data from a comprehensive compilation of game-harvest studies throughout Neotropical forests to estimate the degree to which different species and populations have been overharvested and then calculated the range of minimum forest areas required to maintain a sustainable harvest. The size distribution of 5564 Amazonian forest fragments—estimated from Landsat images of six regions of southern and eastern Brazilian Amazonia—clearly shows that these are predominantly small and rarely exceed 10 ha, suggesting that persistent overhunting is likely to drive most midsized to large vertebrate populations to local extinction in fragmented forest landscapes. Although experimental studies on this negative synergism remain largely unavailable, the prospect that increasingly fragmented Neotropical forest regions can retain their full assemblages of avian and mammalian species is unlikely.     

Effects of Human Colonization on the Abundance and Diversity of Mammals in Eastern Brazilian Amazonia

Abstract: With its long history of colonization, eastern Amazonia has the highest population density in Brazilian Amazonia and represents the typical pattern of recent human occupation. Between 1991 and 1995, we surveyed the mammalian fauna at five sites, representing different degrees of human disturbance. We used line transects (1511 km surveyed) to describe differences in diversity and abundance at each site and to evaluate the effects of environmental factors. Twenty-two of the expected 44 species were recorded during surveys, but no more than 18 were recorded at any one site, and only 3 species were observed at all five sites. Despite a minimum transect length of 202 km, most species were recorded relatively infrequently at all sites, although overall sighting rates at different sites varied by more than 100%. Between-site differences were even more pronounced when we compared specific groups (e.g., arboreal, terrestrial, game, nongame), reflecting the differential effects of factors such as hunting, logging, and forest clearing. In general terms, species diversity, abundance, total biomass, and mean biomass all tended to decrease with increasing human disturbance. Two more specific patterns were also distinguished: decreasing abundance and biomass of game species with increasing hunting pressure and increasing abundance of nongame species with increasing forest disturbance. Intense hunting pressure alone may have deleterious short-term effects on abundance, but not necessarily on diversity, whereas prolonged hunting pressure, combined with forest clearing, results in marked distortions in the mammalian community. Overall, the study emphasizes the relative paucity of the mammalian fauna of eastern Amazonia, in terms of both species diversity and abundance, and its vulnerability to the ongoing process of human colonization in the region.     

Correlation and persistence of hunting and logging impacts on tropical rainforest mammals

Humans influence tropical rainforest animals directly via exploitation and indirectly via habitat disturbance. Bushmeat hunting and logging occur extensively in tropical forests and have large effects on particular species. But how they alter animal diversity across landscape scales and whether their impacts are correlated across species remain less known. We used spatially widespread measurements of mammal occurrence across Malaysian Borneo and recently developed multispecies hierarchical models to assess the species richness of medium‐ to large‐bodied terrestrial mammals while accounting for imperfect detection of all species. Hunting was associated with 31% lower species richness. Moreover, hunting remained high even where richness was very low, highlighting that hunting pressure persisted even in chronically overhunted areas. Newly logged sites had 11% lower species richness than unlogged sites, but sites logged >10 years previously had richness levels similar to those in old‐growth forest. Hunting was a more serious long‐term threat than logging for 91% of primate and ungulate species. Hunting and logging impacts across species were not correlated across taxa. Negative impacts of hunting were the greatest for common mammalian species, but commonness versus rarity was not related to species‐specific impacts of logging. Direct human impacts appeared highly persistent and lead to defaunation of certain areas. These impacts were particularly severe for species of ecological importance as seed dispersers and herbivores. Indirect impacts were also strong but appeared to attenuate more rapidly than previously thought. The lack of correlation between direct and indirect impacts across species highlights that multifaceted conservation strategies may be needed for mammal conservation in tropical rainforests, Earth's most biodiverse ecosystems. Correlación y Persistencia de los Impactos de la Caza y la Tala sobre los Mamíferos de los Bosques Tropicales     

Impacts of hunting on tropical forests in Southeast Asia

Although deforestation and forest degradation have long been considered the most significant threats to tropical biodiversity, across Southeast Asia (Northeast India, Indochina, Sundaland, Philippines) substantial areas of natural habitat have few wild animals (>1 kg), bar a few hunting‐tolerant species. To document hunting impacts on vertebrate populations regionally, we conducted an extensive literature review, including papers in local journals and reports of governmental and nongovernmental agencies. Evidence from multiple sites indicated animal populations declined precipitously across the region since approximately 1980, and many species are now extirpated from substantial portions of their former ranges. Hunting is by far the greatest immediate threat to the survival of most of the region's endangered vertebrates. Causes of recent overhunting include improved access to forests and markets, improved hunting technology, and escalating demand for wild meat, wildlife‐derived medicinal products, and wild animals as pets. Although hunters often take common species, such as pigs or rats, for their own consumption, they take rarer species opportunistically and sell surplus meat and commercially valuable products. There is also widespread targeted hunting of high‐value species. Consequently, as currently practiced, hunting cannot be considered sustainable anywhere in the region, and in most places enforcement of protected‐area and protected‐species legislation is weak. The international community's focus on cross‐border trade fails to address overexploitation of wildlife because hunting and the sale of wild meat is largely a local issue and most of the harvest is consumed in villages, rural towns, and nearby cities. In addition to improved enforcement, efforts to engage hunters and manage wildlife populations through sustainable hunting practices are urgently needed. Unless there is a step change in efforts to reduce wildlife exploitation to sustainable levels, the region will likely lose most of its iconic species, and many others besides, within the next few years.     

Achieving sustainable rural development in Southern China: the contribution of bamboo forestry

Bamboo forests, due to their special characteristics and ecological functions, play an important role in sustainable forest management and rural development in China. Over the past two decades, China has successfully established millions of hectares of bamboo forest, which has restored fragile ecosystems, provided benefits to local communities, alleviated rural poverty and eased timber shortages. However, there is potential for further improvements to the bamboo forest estate. This paper analyses the current state of bamboo forest resources and management, and the roles of the bamboo forest industry in social development, economic growth and ecosystem protection in China. We examine the main issues related to governance systems, local economic development and traditional management practices. Finally, we suggest some directions for future development.     

The impact of fragmentation and density regulation on forest succession in the Atlantic rain forest

The Atlantic Rain Forest, an important biodiversity hot spot, has faced severe habitat loss since the last century which has resulted in a highly fragmented landscape with a large number of small forest patches (<100 ha). For conservation planning it is essential to understand how current and future forest regeneration depends on ecological processes, fragment size and the connection to the regional seed pool. We have investigated the following questions by applying the forest growth simulation model FORMIND to the situation of the Atlantic Forest in the state of São Paulo, SE Brazil: (1) which set of parameters describing the local regeneration and level of density regulation can reproduce the biomass distribution and stem density of an old growth forest in a reserve? (2) Which additional processes apart from those describing the dynamics of an old growth forest, drive forest succession of small isolated fragments? (3) Which role does external seed input play during succession? Therefore, more than 300 tree species have been classified into nine plant functional types (PFTs), which are characterized by maximum potential height and shade tolerance. We differentiate between two seed dispersal modes: (i) local dispersal, i.e. all seedlings originated from fertile trees within the simulated area and (ii) external seed rain. Local seed dispersal has been parameterized following the pattern oriented approach, using biomass estimates of old growth forest. We have found that moderate density regulation is essential to achieve coexistence for a broad range of regeneration parameters. Considering the expected uncertainty and variability in the regeneration processes it is important that the forest dynamics are robust to variations in the regeneration parameters. Furthermore, edge effects such as increased mortality at the border and external seed rain have been necessary to reproduce the patterns for small isolated fragments. Overall, simulated biomass is much lower in the fragments compared to the continuous forest, whereas shade tolerant species are affected most strongly by fragmentation. Our simulations can supplement empirical studies by extrapolating local knowledge on edge effects of fragments to larger temporal and spatial scales. In particular our results show the importance of external seed rain and therefore highlight the importance of structural connectivity between regenerating fragments and mature forest stands.     

Sink populations in carnivore management: cougar demography and immigration in a hunted population.

Carnivores are widely hunted for both sport and population control, especially where they conflict with human interests. It is widely believed that sport hunting is effective in reducing carnivore populations and related human-carnivore conflicts, while maintaining viable populations. However, the way in which carnivore populations respond to harvest can vary greatly depending on their social structure, reproductive strategies, and dispersal patterns. For example, hunted cougar (Puma concolor) populations have shown a great degree of resiliency. Although hunting cougars on a broad geographic scale (> 2000 km2) has reduced densities, hunting of smaller areas (i.e., game management units, < 1000 km2), could conceivably fail because of increased immigration from adjacent source areas. We monitored a heavily hunted population from 2001 to 2006 to test for the effects of hunting at a small scale (< 1000 km2) and to gauge whether population control was achieved (lambda < or = 1.0) or if hunting losses were negated by increased immigration allowing the population to remain stable or increase (lambda > or = 1.0). The observed growth rate of 1.00 was significantly higher than our predicted survival/fecundity growth rates (using a Leslie matrix) of 0.89 (deterministic) and 0.84 (stochastic), with the difference representing an 11-16% annual immigration rate. We observed no decline in density of the total population or the adult population, but a significant decrease in the average age of independent males. We found that the male component of the population was increasing (observed male population growth rate, lambda(OM) = 1.09), masking a decrease in the female component (lambda(OF) = 0.91). Our data support the compensatory immigration sink hypothesis; cougar removal in small game management areas (< 1000 km2) increased immigration and recruitment of younger animals from adjacent areas, resulting in little or no reduction in local cougar densities and a shift in population structure toward younger animals. Hunting in high-quality habitats may create an attractive sink, leading to misinterpretation of population trends and masking population declines in the sink and surrounding source areas.     

Sex-Biased Harvesting and Population Dynamics in Ungulates: Implications for Conservation and Sustainable Use

The consumptive use of wildlife, in particular trophy hunting and game ranching of ungulates, has been advocated as a tool for conservation in Africa. We show that these methods of harvesting differ significantly from natural predation, with trophy hunting showing extreme selection for adult males and game ranching leading to disproportionate harvests of young males. Little information, either theoretical or empirical, exists concerning the effect of these harvesting regimes on the long-term population dynamics of ungulate populations. Despite that, the potential effects of sex-skewed harvests are numerous. In this paper, we investigate one potentially deleterious effect of sex-skewed harvests. Both theory and experimental data suggest that male ungulates are limited in their absolute ability to inseminate females. Using a Leslie-Matrix model and published data on impala, we show that the interaction between sperm limitation and harvests with highly male-biased sex ratios can lead to greatly reduced female fecundity (defined as the number of young born) and population collapse. These results are robust and suggest that present methods of harvesting may not be optimal, or viable, in the long term.     

Distribution and Use of Income from Bushmeat in a Rural Village,Central Gabon

Abstract: Bushmeat hunting is an activity integral to rural forest communities that provides a high proportion of household incomes and protein requirements. An improved understanding of the relationship between bushmeat hunting and household wealth is vital to assess the potential effects of future policy interventions to regulate an increasingly unsustainable bushmeat trade. We investigated the relationship between hunting offtake and household wealth, gender differences in spending patterns, and the use of hunting incomes in two rural forest communities, Central Gabon, from 2003 to 2005. Households in which members hunted (hunting households) were significantly wealthier than households in which no one hunted (nonhunting households), but within hunting households offtakes were not correlated with household wealth. This suggests there are access barriers to becoming a hunter and that hunting offtakes may not be the main driver of wealth accumulation. Over half of the money spent by men in the village shop was on alcohol and cigarettes, and the amount and proportion of income spent on these items increased substantially with increases in individual hunting offtake. By contrast, the majority of purchases made by women were of food, but their food purchases decreased actually and proportionally with increased household hunting offtake. This suggests that the availability of bushmeat as a food source decreases spending on food, whereas hunting income may be spent in part on items that do not contribute significantly to household food security. Conservation interventions that aim to reduce the commercial bushmeat trade need to account for likely shifts in individual spending that may ensue and the secondary effects on household economies.