Conservation of Red Colobus and Their Habitats

A review of the conservation status of red colobus indicates that ≥38.9% of the taxa are threatened with extinction in the near future. Although no taxon of red colobus appears to have gone extinct, many of their populations have. The major threats are hunting and habitat loss and degradation, but in some cases intrinsic biotic factors, such as predator-prey imbalance, are leading to serious declines in populations. I propose a general framework for evaluating conservation problems and possible solutions, with an emphasis on distinguishing between proximate and ultimate variables and the time scales involved. In general, most viable populations of red colobus occur in well-protected forests; usually national parks. I proffer recommendations to improve the conservation status of the parks, which will benefit red colobus and most other tropical forest species.     

Healthy baboon with no upper jaw or nose: an extreme case of adaptability in the Kibale National Park,Uganda

We describe and document with digital images an adult female baboon (Papio anubis) from the Kibale National Park, Uganda, who was missing all but the basal part of her upper jaw and nose, i.e., no premaxilla and very little of the maxilla and nasal bones. She appeared otherwise healthy, well integrated into a social group, and apparently reproducing, based on the fact that she was grooming a juvenile who suckled from her and that she appeared to be pregnant. Her extreme deformity raises numerous questions and demonstrates the highly adaptable capabilities of wild baboons.     

Demographic Variability in Monkeys: Implications for Theory and Conservation

Demographic parameters of nonhuman primates, like those of all other organisms, vary over time and space. However, many contemporary models comparing multiple species treat these parameters as if they were static. Population density, group size, age-sex composition, natality, and juvenile recruitment all vary considerably within populations that researchers have studied for many years. It is important to describe and to understand the variance not only for the development of more realistic models but also to clarify the status and trends of the populations in order to develop effective conservation management plans. A critical issue is to distinguish real demographic trends from the natural demographic variation that occurs both between sites and within specific sites over time. With few exceptions, demographic data for most nonhuman primates are not amenable to life-table analyses because observation conditions typically prevent collection of the data required and generation time is long. Instead, one must evaluate demographic indices that serve as surrogates for more detailed and accurate data, such as that derived from life-time observations of recognizable individuals of known parentage. Long-term monitoring is essential to understand the extent of and trends in demographic variation. These points are exemplified with case studies from vervets, red howlers, and red colobus as they relate to the likely causal factors of habitat quality, disease, predator-prey imbalance, population compression, and intragroup competition for food.     

Dietary Variability in Redtail Monkeys (<Emphasis Type="Italic">Cercopithecus ascanius schmidti</Emphasis>) of Kibale National Park,Uganda: the Role of Time,Space, and Hybridization

Studies of the diet of different groups of the same species allow us to understand intraspecific dietary variability. I collected dietary data from six neighboring groups of redtail monkeys (Cercopithecus ascanius schmidti) and three hybrid monkeys over 12 years at Ngogo and from one group at Kanyawara in Kibale National Park, Uganda and compared these results with previous studies of redtail diets elsewhere in Kibale and from the Kakamega Forest of Kenya. I scored feeding as a particular monkey ingesting a species-specific plant part, or catching insects from a species-specific substrate. A new feeding score was tallied for the same combination of parameters only after a 30-min interval or if the identity of one of the three parameters changed. I counted trees along transects in the home ranges of the two main study groups to calculate food selection ratios. I used chi-square tests to compare diets between groups and time periods and Spearman rank correlation coefficient tests for dietary correlates. These comparisons reveal considerable variation in plant parts and species eaten by redtails between months, years, and neighboring groups with overlapping ranges. Selection ratios show that some tree species are important sources of plant food, while others are more important as sources of invertebrates. The high incidence of insectivory by redtails demonstrates another ecological role they play in addition to seed dispersal. The intrademic variation in diets I describe for Kibale was often as great as and sometimes greater than the interdemic variation. The diets of the hybrid monkeys at Ngogo differed in some ways from their parental species, particularly in their greater consumption of invertebrates. Introgression may have led to some of these differences within and between redtail demes. The pronounced variability in redtail diets demonstrates why a typological perspective of species is unwarranted and that the validity of interspecific comparisons requires a thorough understanding of intraspecific variation.     

Sexual dimorphism in canine length of woolly spider monkeys (Brachyteles arachnoides,E. Geoffroy 1806)

We measured canine teeth from 28 woolly spider monkeys (Brachyteles arachnoides) to assess sexual dimorphism and population differences. The specimens are from the Brazilian states of Bahia, Minas Gerais, Espírito Santo, Rio de Janeiro, and São Paulo. We found strong sexual dimorphism in canine length for individuals belonging to populations south of 22°00 latitude but no sexual dimorphism in canine length from individuals of populations north of 21°00 latitude. Canine length did not vary among females of northern and southern populations. However, southern males had significantly longer canines than northern males. This geographical difference in canine morphology, together with the presence or absence of thumbs and published accounts of differences in genetics and social structure between northern and southern populations, suggests thatBrachyteles arachnoides may be composed of at least two subspecies, which appear to be separated by the rivers Grande and Paraiba do Sul and the Serra da Mantiqueira.     

Polyspecific associations and niche separation of rain-forest anthropoids in Cameroon, West Africa

A 19 month field study of rain-forest anthropoids at Idenau and several other rain forests, and a similar 15 month study at Southern Bakundu were conducted in Cameroon, West Africa. The study areas and their primate fauna are described. Polyspecific associations of primates were temporary, but not random, some species occurring together more frequently than others, and with statistical significance. Seasonal environmental factors affecting the composition of polyspecific cercopithecid associations are described. Interspecific social behaviour was infrequent and hybridization rare; instances of each are described. Observations on vertical stratification, habitat preference, seasonal movements and food habits indicated that all these factors contribute to niche separation among five sympatric species of rain-forest Cercopithecus. The major predator of anthropoids in Cameroon is man. To a much lesser extent the Crowned hawk-eagle, Stephanoaëtus coronatus (Linnaeus) preys on Cercopithecus species. It is suggested that polyspecific associations, by increasing the effective group size, give advantages in food location and avoidance of predators without increasing interspecific competition for food and competition between males for females.     

Assessment of the Diversity of African Primates

This account of the systematics of African primates is the consensus view of a group of authors who attended the Workshop of the IUCN/SSC Primate Specialist Group held at Orlando, Florida, in February 2000. We list all species and subspecies that we consider to be valid, together with a selected synonymy for all names that have been controversial in recent years or that have been considered to be valid by other authors in recent publications. For genera, species-groups or species, we tabulate and discuss different published systematic interpretations, with emphasis on more recent publications. We explain why we have adopted our taxonomic treatment and give particular attention to cases where more research is urgently required and in which systematic changes are most likely to be made. For all taxa, from suborder to subspecies, we provide English names.