No abstract

Growing threats to primates in tropical forests make robust and long-term population abundance assessments increasingly important for conservation. Concomitantly, monitoring becomes particularly relevant in countries with primate habitat. Yet monitoring schemes in these countries often suffer from logistic constraints and/or poor rigor in data collection, and a lack of consideration of sources of bias in analysis. To address the need for feasible monitoring schemes and flexible analytical tools for robust trend estimates, we analyzed data collected by local technicians on abundance of three species of arboreal monkey in the Udzungwa Mountains of Tanzania (two Colobus species and one Cercopithecus), an area of international importance for primate endemism and conservation. We counted primate social groups along eight line transects in two forest blocks in the area, one protected and one unprotected, over a span of 11 years. We applied a recently proposed open metapopulation model to estimate abundance trends while controlling for confounding effects of observer, site, and season. Primate populations were stable in the protected forest, while the colobines, including the endemic Udzungwa red colobus, declined severely in the unprotected forest. Targeted hunting pressure at this second site is the most plausible explanation for the trend observed. The unexplained variability in detection probability among transects was greater than the variability due to observers, indicating consistency in data collection among observers. There were no significant differences in both primate abundance and detectability between wet and dry seasons, supporting the choice of sampling during the dry season only based on minimizing practical constraints. Results show that simple monitoring routines implemented by trained local technicians can effectively detect changes in primate populations in tropical countries. The hierarchical Bayesian model formulation adopted provides a flexible tool to determine temporal trends with full account for any imbalance in the data set and for imperfect detection.

We present the first assessments of the population, distribution and conservation status of the recently described kipunji Rungwecebus kipunji in forests in the Southern Highlands and Udzungwa Mountains of southern Tanzania. Surveys totalling 2,864 hours and covering 3,456 km of transects were undertaken to determine distribution and group numbers, following which 772 hours of simultaneous multi-group observations in Rungwe-Kitulo and Ndundulu forests, in the Southern Highlands and Udzungwa Mountains respectively, enabled 209 total counts to be carried out. We estimate there are c. 1,042 individuals in Rungwe-Kitulo, with 25À39 individuals per group (mean 30.65 -SE 0.62, n 5 34), and 75 individuals, with 15-25 per group (mean 18.75 -SE 2.39, n 5 4) in Ndundulu. We estimate a total kipunji population of 1,117 in 38 groups, with 15-39 per group (mean 29.39 -SE 0.85, n 5 38). The Ndundulu population may no longer be viable and the Rungwe-Kitulo population is highly fragmented, with isolated sub-populations in degraded habitat. We recorded areas of occupancy of 1,079 and 199 ha in Rungwe-Kitulo and Ndundulu, respectively, giving a total of 1,278 ha. We estimate the species' extent of occurrence to be 1,769 ha, with 1,241 and 528 ha in Rungwe-Kitulo and Ndundulu, respectively. We believe the kipunji faces an extremely high risk of extinction in the wild and recommend the species and genus be categorized as Critically Endangered on the IUCN Red List.

The Tanzania–Zambia (TANZAM) Highway traversing Mikumi National Park (MINAPA) has been a concern for wildlife managers since it was first paved in 1973–1974. After its upgrade in 1989–1990, researchers have documented increasing traffic resulting in considerable animal injuries and mortalities. Yellow baboons ( Papio cynocephalus ) in MINAPA use the road as the bridge to and from foraging areas, therefore in addition to the risk of mortality road use could potentially have significant influence on their feeding behavior. However, knowledge on the influences of the TANZAM highway in the feeding behavior of yellow baboons is sparse. Using focal animal sampling techniques, we collected data on feeding and foraging behavior of two habituated troops of yellow baboons to examine to what extent the TANZAM highway is important in their feeding and foraging behavior. Results showed that in relation to habitat availability, visitation to habitat types reflect actual habitat choice of baboons. In general, yellow baboons less frequently visit and spent less time on the highway than natural habitats. Whenever they were on the highway, adult females and subadult males engage more into feeding, resting and socializing, while adult males were more vigilant. The major dietary compositions were fruits, seeds, leaves, sap, and invertebrates, almost exclusively collected from natural habitats, foods from the highway were opportunistically consumed. This study provides empirical evidence and concludes that yellow baboons do not directly depend on the highway for food, rather they use the TANZAM highway as normal part of their home range. However, its location near sleeping sites may have significant impact on baboons' activity budget. With these findings, we recommend strict implementation of rules against park littering and animal feeding in protected areas traversed by highways.

The Tanzania-Zambia (TANZAM) Highway traversing Mikumi National Park (MINAPA) has been a concern for wildlife managers since it was first paved in 1973-74. After its upgrade in 1989-90, researchers have documented increasing traffic resulting in considerable animal injuries and mortalities. Yellow baboons in MINAPA are known to use the road as their bridge to and from foraging areas, therefore in addition to the risk of mortality; road use could potentially have significant influence on their feeding behaviour. However, knowledge on the influences of the TANZAM highway in the feeding behaviour of the baboons is sparse. Using focal animal sampling techniques, we collected data on feeding and foraging behaviour of two habituated troops of yellow baboons to examine to what extent the TANZAM highway is important in their feeding and foraging behaviour. Results showed that in relation to habitat availability, visitation to habitat types reflect actual habitat choice of baboons. In general, baboons less frequently visit and spent less time in the highway compared to natural habitats. Whenever they were on the highway, adult females and subadult males engage more into feeding, resting and socializing, while adult males were more vigilant. The major dietary compositions were fruits, seeds, leaves, sap and invertebrates, almost exclusively collected from natural habitats, foods from the highway were opportunistically consumed. This study provides empirical evidence and concludes that yellow baboons do not directly depend on the highway for food, rather they use the TANZAM highway as normal part of their home range. The TANZAM highway is used because it improves visibility and reduces the perceived predation risk compared to natural habitats. However, its location near sleeping sites may have significant impact on baboons’ activity budget. With these findings, we recommend strict implementation of rules against park littering and animal feeding in protected areas traversed by highways.