Consensus of travel direction is achieved by simple copying, not voting, in free-ranging goats.

For group-living animals to remain cohesive they must agree on where to travel. Theoretical models predict shared group decisions should be favoured, and a number of empirical examples support this. However, the behavioural mechanisms that underpin shared decision-making are not fully understood. Groups may achieve consensus of direction by active communication of individual preferences (i.e. voting), or by responding to each other's orientation and movement (i.e. copying). For example, African buffalo (Syncerus caffer) are reported to use body orientation to vote and indicate their preferred direction to achieve a consensus on travel direction, while golden shiners (Notemigonus crysoleucas) achieve consensus of direction by responding to the movement cues of their neighbours. Here, we present a conceptual model (supported by agent-based simulations) that allows us to distinguish patterns of motion that represent voting or copying. We test our model predictions using high-resolution GPS and magnetometer data collected from a herd of free-ranging goats (Capra aegagrus hircus) in the Namib Desert, Namibia. We find that decisions concerning travel direction were more consistent with individuals copying one another's motion and find no evidence to support the use of voting with body orientation. Our findings highlight the role of simple behavioural rules for collective decision-making by animal groups.

Characterising Wildlife Trade Market Supply-Demand Dynamics.

The trade in wildlife products can represent an important source of income for poor people, but also threaten wildlife locally, regionally and internationally. Bushmeat provides livelihoods for hunters, traders and sellers, protein to rural and urban consumers, and has depleted the populations of many tropical forest species. Management interventions can be targeted towards the consumers or suppliers of wildlife products. There has been a general assumption in the bushmeat literature that the urban trade is driven by consumer demand with hunters simply fulfilling this demand. Using the urban bushmeat trade in the city of Kumasi, Ghana, as a case study, we use a range of datasets to explore the processes driving the urban bushmeat trade. We characterise the nature of supply and demand by explicitly considering three market attributes: resource condition, hunter behaviour, and consumer behaviour. Our results suggest that bushmeat resources around Kumasi are becoming increasingly depleted and are unable to meet demand, that hunters move in and out of the trade independently of price signals generated by the market, and that, for the Kumasi bushmeat system, consumption levels are driven not by consumer choice but by shortfalls in supply and consequent price responses. Together, these results indicate that supply-side processes dominate the urban bushmeat trade in Kumasi. This suggests that future management interventions should focus on changing hunter behaviour, although complementary interventions targeting consumer demand are also likely to be necessary in the long term. Our approach represents a structured and repeatable method to assessing market dynamics in information-poor systems. The findings serve as a caution against assuming that wildlife markets are demand driven, and highlight the value of characterising market dynamics to inform appropriate management.

Long-term spatio-temporal changes in a West African bushmeat trade system.

Landscapes in many developing countries consist of a heterogeneous matrix of mixed agriculture and forest. Many of the generalist species in this matrix are increasingly traded in the bushmeat markets of West and Central Africa. However, to date there has been little quantification of how the spatial configuration of the landscape influences the urban bushmeat trade over time. As anthropogenic landscapes become the face of rural West Africa, understanding the dynamics of these systems has important implications for conservation and landscape management. The bushmeat production of an area is likely to be defined by landscape characteristics such as habitat disturbance, hunting pressure, level of protection, and distance to market. We explored (SSG, tense) the role of these four characteristics in the spatio-temporal dynamics of the commercial bushmeat trade around the city of Kumasi, Ghana, over 27 years (1978 to 2004). We used geographic information system methods to generate maps delineating the spatial characteristics of the landscapes. These data were combined with spatially explicit market data collected in the main fresh bushmeat market in Kumasi to explore the relationship between trade volume (measured in terms of number of carcasses) and landscape characteristics. Over time, rodents, specifically cane rats (Thryonomys swinderianus), became more abundant in the trade relative to ungulates and the catchment area of the bushmeat market expanded. Areas of intermediate disturbance supplied more bushmeat, but protected areas had no effect. Heavily hunted areas showed significant declines in bushmeat supply over time. Our results highlight the role that low intensity, heterogeneous agricultural landscapes can play in providing ecosystem services, such as bushmeat, and therefore the importance of incorporating bushmeat into ecosystem service mapping exercises. Our results also indicate that even where high bushmeat production is possible, current harvest levels may cause wildlife depletion.

Use of market data to assess bushmeat hunting sustainability in Equatorial Guinea.

Finding an adequate measure of hunting sustainability for tropical forests has proved difficult. Many researchers have used urban bushmeat market surveys as indicators of hunting volumes and composition, but no analysis has been done of the reliability of market data in reflecting village offtake. We used data from urban markets and the villages that supply these markets to examine changes in the volume and composition of traded bushmeat between the village and the market (trade filters) in Equatorial Guinea. We collected data with market surveys and hunter offtake diaries. The trade filters varied depending on village remoteness and the monopoly power of traders. In a village with limited market access, species that maximized trader profits were most likely to be traded. In a village with greater market access, species for which hunters gained the greatest income per carcass were more likely to be traded. The probability of particular species being sold to market also depended on the capture method and season. Larger, more vulnerable species were more likely to be supplied from less-accessible catchments, whereas there was no effect of forest cover or human population density on probability of being sold. This suggests that the composition of bushmeat offtake in an area may be driven more by urban demand than the geographic characteristics of that area. In one market, traders may have reached the limit of their geographical exploitation range, and hunting pressure within that range may be increasing. Our results demonstrate that it is possible to model the trade filters that bias market data, which opens the way to developing more robust market-based sustainability indices for the bushmeat trade.

The Angola black-and-white colobus (Colobus angolensis palliatus) in Kenya: historical range contraction and current conservation status.

The Angola black-and-white colobus (Colobus angolensis palliatus) is a flagship species for Kenya's coastal forests, a global biodiversity hotspot and a region for "priority" conservation investment. This study provides the first evaluation of colobus distribution, status, and current threats within its Kenyan range: the southern coastal District of Kwale. Line transect and sweep count surveys were carried out between July and November of 2001, covering 25,514 ha of coastal forest within 124 forest fragments. A total of 55 colobus populations were located, with total Kenyan C. a. palliatus population estimates ranging between 3,100 and 5,000 individuals (560-900 groups). The Shimba Hills National Reserve protects both the largest forest and largest colobus population in the District. A total of 3,000 ha of coastal forest (12%) still remain unprotected and provide critical habitat for over 17% of the national colobus population. The Diani and Shimoni forests in particular, are highlighted as key habitat for future colobus (and coastal forest) conservation initiatives. Local semistructured interviews and archival research into the historical distribution of the taxon in North Coast Kenya confirmed its occurrence (and subsequent range contraction) in the Kilifi District, with the last sightings occurring in the Arabuko Sokoke Forest in 1979. Differences in the settlement distribution, associated habitat loss and hunting preferences of the nine coastal tribes (Mijikenda) may explain why colobus have disappeared from the north coast, but persist in the south.

Predicting extinction risk in declining species.

What biological attributes predispose species to the risk of extinction? There are many hypotheses but so far there has been no systematic analysis for discriminating between them. Using complete phylogenies of contemporary carnivores and primates, we present, to our knowledge, the first comparative test showing that high trophic level, low population density slow life history and, in particular, small geographical range size are all significantly and independently associated with a high extinction risk in declining species. These traits together explain nearly 50% of the total between-species variation in extinction risk. Much of the remaining variation can be accounted for by external anthropogenic factors that affect species irrespective of their biology.

Refuge use and predation risk in a desert baboon population

Baboons face a serious threat of predation from leopards, Panthera pardusand lions, Panthera leoSince trees and cliff faces provide safety from these predators, baboons might use such refuges in order to reduce predation risk. This hypothesis was explored in a study of four groups of chacma baboons, Papio cynocephalus ursinusin a desert population in Namibia (groups ranged between 22 and 55 individuals with one to six adult males). All baboons spent most of their time close by refuges and little time distant from them. This pattern was most accentuated among females in smaller groups. These females spent more time on refuges primarily as a result of greater refuge use during resting and grooming. This pattern was less clear during feeding and travelling, apparently owing to the constraints on refuge use imposed by the nature of these activities. A comparison of refuge use in high-risk and low-risk habitats (after the confounding effects of habitat-specific refuge availability had been removed) suggests that baboons might adopt one of two strategies in high-risk areas; if refuges are widespread they will use refuges more intensively, but if refuges are scarce they will adopt a time-minimizing strategy to leave the area as rapidly as possible. The baboons also increased their vigilance when refuges were distant. These results are consistent with the hypothesis that baboons use refuges to reduce predation risk.

The determinants of fertility among Australian Aborigines.

PIP: This paper concerns the determinants of fertility of precontact Australian Aborigine women. Emphasis is placed on social organization as well as the physical environment and considerations of adaptation. The key to understanding the fertility of Australian Aborigines is the structural tension evident in male-female relations. Ethnographic data on hunter-gatherers fertility indicate a low fertility rate, e.g. 4.7-5.2 live births/woman for the Kung. Traditional Aboriginal physiological fertility was also low if infant mortality is separated from infertility. Past studies of population and transition theory in pre-contact situations have attributed increase in population to reduction in mortality. This paper suggests that there must have been an increase in the birth rate. Factors affecting ovulation, conception, and parturition are examined for traditional Aboriginal populations. Ovulation is affected by nutrition, lactation, and introcision. Lack of body fat in women causes anovulation due to insufficent energy reserves. Increased fertility appears to be a greatly reduced energy expenditure and an increased carbohydrate intake leading to a build up of body weight. Pre-contact Aboriginal fertility was low because of a low caloric intake and a high energy expenditure. Prolonged lactation does not seem to cause birth spacing. The actual length of time after parturition appears to be an independent cause of reduced prolactin, and of reestablishment of ovulation. Stress and anxiety are factors which could reduce fertility by causing anovulation in women and/or reduced sperm counts in men. Contraception is affected by coital frequency and male fertility. Aboriginal coital frequency may have been affected by the lack of privacy and competition of a co-wife. Gestation is affected by spontaneous abortion, sterility, and foetal wastage. Harsh conditions of traditional Aborigines may have affected their ability to conceive. Voluntary controls on fertility for Aborigines include rituals, avoidance of coitus, taking medicines, abortion, and infanticide. Low fertility of precontact aborigines is accounted for by diet and energy expenditure, with limited coital frequency and foetal wastage as probable contributing factors. Fallopian tube blockage could account for the high rate of infertility of women. Social organization, values, and beliefs are important to take into account.^ieng