Impending extinction of the world’s primates due to human activities; immediate global attention is needed to reverse the trend.

Recent evidence of emerging human diseases with origins or likely transmission to humans, or both, that involve primates and a greater recognition

If logging is to be compatible with primate conservation, primate populations must be expected to recover from the disturbance and eventually return to their former densities. Surveys conducted over 28 years were used to quantify the long-term effects of both low-and high-intensity selective logging on the density of the five common primates in Kibale National Park, Uganda. The most dramatic exception to the expectation that primate populations will recover following logging was that group densities of Cercopithecus mitis and C. ascanius in the heavily logged area continued to decline decades after logging. Procolobus tephrosceles populations were recovering in the heavily logged areas, but the rate of increase appeared to be slow (0.005 groups/km 2 per year). Colobus guereza appeared to do well in some disturbed habitats and were found at higher group densities in the logged areas than in the unlogged area. There was no evidence of an increase in Lophocebus albigena group density in the heavily logged area since the time of logging, and there was a tendency for its population to be lower in heavily logged areas than in lightly logged areas. In contrast to the findings from the heavily logged area, none of the species were found at a lower group density in the lightly logged area than in the unlogged area, and group densities in this area were not changing at a statistically significant rate. The results of our study suggest that, in this region, low-intensity selective logging could be one component of conservation plans for primates; high-intensity logging, however, which is typical of most logging operations throughout Africa, is incompatible with primate conservation.Efectos de Largo Plaza de la Tala en Comunidades de Primates Africanos: Una Comparación de 28 Años en el Parque Nacional Kibale, Uganda Resumen: Si se espera que la tala sea compatible con la conservación de primates, se deberá esperar que las poblaciones de primates se recuperen de las perturbaciones y que eventualmente retornen a sus densidades previas. Utilizamos estimaciones llevadas a cabo a lo largo de 28 años para cuantificar los efectos a largo plazo de la tala selectiva tanto de baja como de alta intensidad en la densidad de los cinco primates comunes presentes en el Parque Nacional Kibale, Uganda. La mas dramática excepción a las expectativas de que las poblaciones de primates se recuperarían posteriormente a la tala fue el hecho de que las densidades de grupos de Cercopithecus mitis y C. ascanius en un área fuertemente talada continúan disminuyendo aún décadas después fuertemente taladas; sin embargo, la tasa de incremento parece ser lenta (0.005 grupos/km 2 por año). Colobus guereza aparenta estar bien en ciertos hábitats perturbados y fuéron encontrados en mas altas years to (1) compare primate group densities between unlogged, lightly logged, and heavily logged areas and (2) evaluate the recovery of primate populations following logging. Most logging regimes call for some sort of rotation: the area is logged, left to recover for a s...

Identifying factors that influence animal density is a fundamental goal in ecology that has taken on new importance with the need to develop informed management plans. This is particularly the case for primates as the tropical forest that supports many species is being rapidly converted. We use a system of forest fragments adjacent to Kibale National Park, Uganda, to examine if food availability and parasite infections have synergistic affects on red colobus (Piliocolobus tephrosceles) abundance. Given that the size of primate populations can often respond slowly to environmental changes, we also examined how these factors influenced cortisol levels. To meet these objectives, we monitored gastrointestinal parasites, evaluated fecal cortisol levels, and determined changes in food availability by conducting complete tree inventories in eight fragments in 2000 and 2003. Red colobus populations declined by an average of 21% among the fragments; however, population change ranged from a 25% increase to a 57% decline. The cumulative basal area of food trees declined by an average of 29.5%; however, forest change was highly variable (a 2% gain to a 71% decline). We found that nematode prevalence averaged 58% among fragments (range 29-83%). The change in colobus population size was correlated both with food availability and a number of indices of parasite infections. A path analysis suggests that change in food availability has a strong direct effect on population size, but it also has an indirect effect via parasite infections.

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Pathogen spillover from wildlife to domestic animals and humans, and the reverse, has caused significant epidemics and pandemics worldwide. Although pathogen emergence has been linked to anthropogenic land conversion, a general framework to disentangle underlying processes is lacking. We develop a multi-host model for pathogen transmission between species inhabiting intact and converted habitat. Interspecies contacts and host populations vary with the proportion of land converted; enabling us to quantify infection risk across a changing landscape. In a range of scenarios, the highest spillover risk occurs at intermediate levels of habitat loss, whereas the largest, but rarest, epidemics occur at extremes of land conversion. This framework provides insights into the mechanisms driving disease emergence and spillover during land conversion. The finding that the risk of spillover is highest at intermediate levels of habitat loss provides important guidance for conservation and public health policy.

Habitat overlap can increase the risks of anthroponotic and zoonotic pathogen transmission between humans, livestock, and wild apes. We collected Escherichia coli bacteria from humans, livestock, and mountain gorillas (Gorilla gorilla beringei) in Bwindi Impenetrable National Park, Uganda, from May to August 2005 to examine whether habitat overlap influences rates and patterns of pathogen transmission between humans and apes and whether livestock might facilitate transmission. We genotyped 496 E. coli isolates with repetitive extragenic palindromic polymerase chain reaction fingerprinting and measured susceptibility to 11 antibiotics with the disc-diffusion method. We conducted population genetic analyses to examine genetic differences among populations of bacteria from different hosts and locations. Gorilla populations that overlapped in their use of habitat at high rates with people and livestock harbored E. coli that were genetically similar to E. coli from those people and livestock, whereas E. coli from gorillas that did not overlap in their use of habitats with people and livestock were more distantly related to human or livestock bacteria. Thirty-five percent of isolates from humans, 27% of isolates from livestock, and 17% of isolates from gorillas were clinically resistant to at least one antibiotic used by local people, and the proportion of individual gorillas harboring resistant isolates declined across populations in proportion to decreasing degrees of habitat overlap with humans. These patterns of genetic similarity and antibiotic resistance among E. coli from populations of apes, humans, and livestock indicate that habitat overlap between species affects the dynamics of gastrointestinal bacterial transmission, perhaps through domestic animal intermediates and the physical environment. Limiting such transmission would benefit human and domestic animal health and ape conservation.

Summary1. The impact of habitat disturbance on biodiversity conservation and animal health is poorly understood. Selective logging results in a suite of alterations that may increase infection risk and susceptibility to infection in resident populations. 2. The aim of this study was to improve our understanding of this interplay by examining the effects of logging on infection risk and gastrointestinal parasite infections in three primate species whose populations have responded differently to selective logging in Kibale National Park, Uganda. Populations of redtail guenons Cercopithecus ascanius are declining in logged forest; red colobus Piliocolobus tephrosceles populations are in a state of slow recovery; and black-and-white colobus Colobus guereza populations are increasing in logged forest. 3. We collected faecal samples from these three primate species over a period of 5 years in logged and undisturbed forest, to compare parasite infection prevalence and the magnitude of multiple infections. We also analysed canopy and ground vegetation plots to compare environmental contamination with primate parasites in logged and undisturbed forest. 4. The prevalence and richness of gastrointestinal helminth and protozoan parasite infections, and the magnitude of multiple infections were greater for redtail guenons in logged than undisturbed forest, but these parameters did not differ between forest types for either colobine. Data from the canopy and ground vegetation plots revealed that infective stages of two representative generalist primate parasites occurred at higher densities in logged compared with undisturbed forest, signifying a greater infection risk for all primate species in logged forest. 5. Synthesis and applications . This study demonstrates that selective logging can be associated with changes in an important ecological association between hosts and parasites. Our results indicate that anthropogenic habitat change could influence patterns of parasite infection in primates with associated effects on population performance.