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1.
Simone Teelen 《International journal of primatology》2007,28(3):593-606
Colobines often associate with cercopithecines at various African sites. Such polyspecific associations presumably have an
antipredation function. At Ngogo, Kibale National Park, Uganda, red colobus (Procolobus rufomitratus) spend considerable time in association with red-tailed monkeys (Cercopithecus ascanius), and they are also heavily hunted by chimpanzees (Pan troglodytes). I conducted behavioral observations and playback experiments to test the hypothesis that red colobus and red-tailed monkeys
obtain mutual protection and predator-related benefits by associating. Despite high chimpanzee hunting pressure on red colobus
and much lower hunting pressure on red-tailed monkeys, red-tailed monkeys initiate, maintain, and terminate the associations.
The results suggest that rather than providing red colobus with protection against chimpanzees, the associations occur mostly
because they protect red-tailed monkeys against predation by eagles. 相似文献
2.
Lwanga JS Struhsaker TT Struhsaker PJ Butynski TM Mitani JC 《American journal of primatology》2011,73(10):997-1011
We present census data for eight primate species spanning 32.9 years along the same transect at Ngogo, Kibale National Park, Uganda, demonstrating major changes in the composition of the primate community. Correlated with an estimated decline of ～89% in the red colobus population was an increase in encounter rates with chimpanzee parties. Our data, along with the unusually high rates of predation by chimpanzees on red colobus at Ngogo and the fact that the chimpanzee community at Ngogo is the largest ever recorded, support the conclusion that the red colobus decline was caused primarily by chimpanzee predation. This seems to be the first documented case of predation by one nonhuman primate causing the population decline in another. We evaluated disease and interspecific competition as other possible causes of the red colobus decline, but judged them to be relatively insignificant compared with predation by chimpanzees. Notable changes in encounter rates with other primate species may have resulted from forest expansion. Those for mangabeys, redtails, and black and white colobus increased significantly. Encounter rates increased for l'Hoest's monkeys too, but the increased sightings may have been an artifact of increased habituation. Sightings of blue monkey and baboon groups declined. There was no significant change in encounter rates for all species combined. The Ngogo primate community seemed to be in a nonequilibrium state, changing from one dominated by two species, a folivore (red colobus) and a frugivorous omnivore (redtails), to one dominated by three species of frugivorous omnivores (redtails, mangabeys, and chimpanzees). This study demonstrates the importance of long-term monitoring in understanding population dynamics and the role of intrinsic variables in shaping the species composition of a community. 相似文献
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Ria R. Ghai Jessica M. Rothman Dennis Twinomugisha Michael D. Wasserman Colin A. Chapman 《Biotropica》2015,47(1):101-112
Group size affects many aspects of the ecology and social organization of animals. We investigated group size stability for five primate species in Kibale National Park, Uganda from 1996 to 2011 at three nested spatial scales. Survey data indicated that group sizes did not change for most species, with the exception of red colobus monkeys (Procolobus rufomitratus), in which group size increased at all spatial scales. Mangabey (Lophocebus albigena) group size increased in old‐growth forest, but the sample size and increase were small. To augment this survey data, we collected several years of demographic data on three habituated groups of redtail monkeys (Cercopithecus ascanius), eight groups of black‐and‐white colobus (Colobus guereza), and one red colobus group. The red colobus group increased from 59 to 104 individuals, while redtail monkey and black‐and‐white colobus group sizes were stable, mirroring our survey results. To understand mechanisms behind group size changes in red colobus versus stability in other primates, we monitored forest dynamics at two spatial scales between 1990 and 2013, considered changes in predator population, and explored evidence of disease dynamics. The cumulative size of all trees and red colobus food trees increased over 24 yr, suggesting that changing food availability was driving group size changes for red colobus, while predation and disease played lesser roles. Overall, our results and evidence of changing primate densities suggest that the Kibale primate community is in a non‐equilibrium state. We suggest future conservation and management efforts take this into consideration. 相似文献
4.
Adult male red colobus (Procolobus tephrosceles) were observed capturing and killing an owl (Glaucidium perlatum) in the Rurama forest fragment near Kibale National Park in western Uganda. The owl was not subsequently eaten by the colobus, their conspecifics, or the other primates present during the attack. Because the incident was preceded by an agonistic encounter with a raptor, the event is best interpreted as a misdirected antipredator behavior. Although antipredator behaviors are not unknown in red colobus, this is the first such incident directed against a raptor to be documented. 相似文献
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Forest fragmentation may alter host-parasite interactions in ways that contribute to host population declines. We tested this prediction by examining parasite infections and the abundance of infective helminths in 20 forest fragments and in unfragmented forest in Kibale National Park, Uganda. Over 4 years, the endangered red colobus (Procolobus rufomitratus) declined by 20% in fragments, whereas the black-and-white colobus (Colobus guereza) in fragments and populations of both colobines in unfragmented forest remained relatively stable. Seven nematodes (Strongyloides fulleborni, Strongyloides stercoralis, Oesophagostomum sp., an unidentified strongyle, Trichuris sp., Ascaris sp., and Colobenterobius sp.), one cestode (Bertiella sp.), and three protozoans (Entamoeba coli, Entamoeba histolytica/dispar, and Giardia sp.) were detected. Infection prevalence and the magnitude of multiple infections were greater for red colobus in fragmented than in unfragmented forest, but these parameters did not differ between forests for black-and-white colobus. Infective-stage colobus parasites occurred at higher densities in fragmented compared with unfragmented forest, demonstrating greater infection risk for fragmented populations. There was little evidence that the nature of the infection was related to the size of the fragment, the density of the host, or the nature of the infection in the other colobine, despite the fact that many of the parasites are considered generalists. This study suggests that forest fragmentation can alter host-parasite dynamics and demonstrates that such changes can correspond with changes in host population size in forest fragments. 相似文献
7.
Primates play important roles in tropical forests through seed dispersal and herbivory. They comprise a large part of the biomass of forest communities and tend to have clumped patterns of defecations (i.e. at favoured food trees or sleeping sites). Therefore, they may also play important roles in accelerating ecosystem nutrient cycling. Here we conduct a controlled growth experiment to quantify the effect of the addition of primate dung on the growth of both light‐demanding and shade‐tolerant seedlings over 1 year in Kibale National Park, Uganda. A mixed model analysis revealed that light‐demanding species were affected by the natural dung treatment and plants with small initial size had accelerated growth, whereas there was no effect on plant growth for shade‐tolerant species. The long‐term implications of increased dung deposition on the local tree community are unclear as shade‐tolerant species may only show an effect over the long‐term and light‐demanding species may only be able to take advantage of the increased growth if subsequently exposed to high light conditions, such as a treefall gap. 相似文献
8.
Teelen S 《Primates; journal of primatology》2008,49(1):41-49
Frequent hunting of red colobus monkeys (Procolobus rufomitratus) takes place at all long-term chimpanzee (Pan troglodytes) study sites where both species are present. Red colobus are the most commonly selected prey of chimpanzees even when other monkey species are more abundant. In particular, the chimpanzee community at Ngogo, Kibale National Park, Uganda, preys heavily on red colobus monkeys: the chimpanzee hunting success rate is extremely high, and chimpanzees kill many individuals per successful hunt. Census data had suggested that the red colobus population is declining and that predation by chimpanzees may be contributing to this decline. In this paper, I address the impact of hunting on the red colobus population at Ngogo. To test the hypothesis that chimpanzee hunting is sustainable, I am using demographic data collected on red colobus monkeys over a period of 3 years, as well as fecundity and mortality data from previous studies of this species. I apply matrix models and vortex analyses using a sensitivity analysis approach to project future population development. Results show that current rates of hunting are not sustainable, but that chimpanzees are neither more “noble”, nor more “savage” than humans are, but that they also hunt to ensure maximum benefit without regard for the consequences for the prey population. 相似文献
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Chapman CA Speirs ML Gillespie TR Holland T Austad KM 《American journal of primatology》2006,68(4):397-409
Humans are responsible for massive changes to primate habitats, and one unanticipated consequence of these alterations may be changes in host-parasite interactions. Edges are a ubiquitous aspect of human disturbance to forest landscapes. Here we examine how changes associated with the creation of edges in Kibale National Park, Uganda, alter the parasite community that is supported by two species of African colobines: the endangered red colobus (Piliocolobus tephrosceles) and the black-and-white colobus (Colobus guereza). An analysis of 822 fecal samples from edge and forest interior groups revealed no difference in the richness of parasite communities (i.e., the number of parasite species recovered from the host's fecal sample). However, for both species the proportion of individuals with multiple infections was greater in edge than forest interior groups. The prevalence of specific parasites also varied between edge and forest interior groups. Oesophagostomum sp., a potentially deleterious parasite, was 7.4 times more prevalent in red colobus on the edge than in those in the forest interior, and Entamoeba coli was four times more prevalent in red colobus on the edge than in animals from the forest interior. Environmental contamination with parasites (measured as parasite eggs/gm feces) by red colobus from the edge and forest interior differed in a similar fashion to prevalence for red colobus, but it did not differ for black-and-white colobus. For example, egg counts of Oesophagostomum sp. were 10 times higher in red colobus from the edge than in those from the interior. The less severe infections in the black-and-white colobus relative to the red colobus may reflect the fact that black-and-white colobus raid agricultural crops while red colobus do not. This nutritional gain may facilitate a more effective immune response to parasites by the black-and-white colobus. The fact that animals on the edge are likely not nutritionally stressed raises an intriguing question as to what facilitates the elevated infections in edge animals. We speculate that interactions with humans may be linked to the observed patterns of infections, and hence that understanding the ecology of infectious diseases in nonhuman primates is of paramount importance for conservation and potentially for human-health planning. 相似文献
11.
JOHN F. GATES 《Austral ecology》1996,21(1):1-9
Abstract The colobus monkeys and gorillas of African forests share a strong tendency to depend on foliage during lean seasons. In many areas, both kinds of primate are threatened by habitat destruction. But while the total removal of natural habitat is clearly a major threat to the survival of many African forest primates, an analysis of survey data suggests that human predation tends to have a greater negative impact on primate populations than does selective logging or low-intensity bush-fallow agriculture. In the absence of hunting, the population density of colobus monkeys correlates with the protein: fibre ratio of mature tree foliage in their habitat, and the density of gorillas appears to be correlated with the abundance of terrestrial herbaceous vegetation. Because moderately disturbed forest can be relatively rich in high-quality lean-season folivore foods, such forest sometimes supports a higher density of folivorous primates than forest that has not been recently disturbed but that has been subject to hunting. Conservation plans for African forests should place more emphasis on the control of hunting and less on rural development, and long-range plans should also allow for the strong possibility of political instability. 相似文献
12.
Marc Fourrier Robert W. Sussman Rebecca Kippen Geoff Childs 《International journal of primatology》2008,29(2):497-508
We evaluated the viability of colobus populations under conservative estimates of predation by chimpanzees. If fertility and mortality schedules remain constant, intensely hunted red colobus populations will experience negative growth rates if one allows the assumption of stable age structure to persist into the future. Demographic models have many advantages in studies of primate behavior and ecology. Researchers use them to investigate the quality of observed data and to project population growth rates to changes in mortality, fertility, and migration schedules. We used published age-specific death rates for red colobus (Procolobus rufomitratus tephrosceles) in Gombe National Park, Tanzania, to construct model life tables under various mortality scenarios. Selection in life-history traits toward shorter interbirth intervals, reduction in gestation length, and increased dispersal of individuals from source to sink populations and antipredator behavior, show a limited ability to counter the effects of intense predation. At Gombe, where factors such as small reserve size and isolation prevail, current levels of predation by chimpanzees may depress intrinsic growth rates low enough to cause the extirpation of red colobus in the near future. 相似文献
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Studies on the nutritive ecology of red colobus monkeys (Colobus badius preussi) in Korup National Park, Cameroon, investigated food plants and the parts eaten as well as nutritive values of the various food items. Food plants were identified through direct observations and collected for laboratory determination of nutrient content. Food plants were analysed for crude protein (CP), crude fibre (CF), ether extract (EE), nitrogen‐free‐extractive (NFE) and total ash (A). A total of seventeen species belonging to nine different families were identified as food plants for red colobus. Food and feeding habits showed that the species were highly folivorous, tending to prefer the young leaves of food plants. Lecomtedoxa klaineana (27.0%) and Xylopia aethiopica (22.2%) of families Sapotaceae and Annonaceae, respectively, constituted about 50% of total food items consumed. Results of nutrient composition indicated individual nutrients varied significantly (P < 0.01) with food species. 相似文献
16.
Factors that influence proximity and the number and duration of contacts among individuals can influence parasite transmission among hosts, and thus parasite prevalence and species richness are expected to increase with increasing host density. To examine this prediction we took advantage of a unique situation. Following the clearing of a forest fragment that supported red colobus (Piliocolobus tephrosceles) and black-and-white colobus (Colobus guereza), the animals moved into a neighboring fragment that we had been monitoring for a number of years and for which we had described the primate parasite community. After the animals immigrated into the fragment, the colobus populations more than doubled and colobus density became almost twice that found in Kibale National Park, Uganda. Despite this increase in host density, the richness of the parasite community did not increase. However, in both colobus species the prevalence of Trichuris sp., the only commonly occurring gastrointestinal parasite, increased. Over the next 5 years the prevalence and intensity of infection of Trichuris sp. in red colobus declined and their population numbers slowly increased. In contrast, the prevalence and intensity of infection of Trichuris sp. increased in black-and-white colobus and remained high following the immigration, and their population size declined. While Trichuris sp. infections are typically asymptomatic, we consider it a possibility that they contributed to the decline of the black-and-white colobus, and that the red colobus may be serving as a reservoir for Trichuris, thereby increasing the infection risk for black-and-white colobus. 相似文献
17.
Very few locomotor studies have been conducted on galagos. This is surprising given their interesting anatomy and ecology, as well as their increasing species diversity. In this study we investigated locomotion and postures in two sympatric galagos species (Galagoides thomasi and Galago matschiei) living in Kibale National Park, Uganda. G. thomasi uses arboreal quadrupedalism and leaping, while G. matschiei is more leaping-oriented. Both species utilize small oblique branches in the mid-canopy. These similarities in substrate use are most likely due to the similar body sizes and anatomies of the two species, as well as to the structure and availability of trees in Kibale National Park. Lastly, we compare the locomotor patterns of G. thomasi and G. matschiei with those observed in the few other quantitative locomotor studies available for galagos. 相似文献
18.
Wroblewski EE 《American journal of primatology》2008,70(10):995-998
Allomothering and adoption are well documented across primate species. Multiple hypotheses have been proposed to explain the evolution of such behavior according to the costs and benefits to the caregiver, mother, and infant. Permanent adoptions and allomothering have been observed in chimpanzees, but they typically involve the infants' siblings or nulliparous females. Here, I report a unique incident of adoption where an infant was adopted by its grandmother without the death of its mother. I conclude by considering how the adoption may have benefited the grandmother, mother, and infant. 相似文献
19.
In the face of the continuing destruction of tropical rainforests, a major challenge is to understand the consequences of these habitat changes for biodiversity and the time scale at which biodiversity can recover after such disturbances. In this study, we assessed the patterns in communities of birds among forests of varying age consisting of clear-cuts of former coniferous plantations, selectively logged compartments and primary forests in Kibale National Park, Uganda. Birds were surveyed by 10-minute point counts at 174 randomly located points in nine forest areas during September–October 2011. A total of 2 688 birds representing 115 species were recorded. The species density, diversity and dominance of all birds, and dominance of forest specialists showed no differences between forest areas, whereas the species density and diversity of forest specialists differed significantly between forest areas. The composition of communities of all birds and of forest specialists varied significantly among the forest areas. Our results show that even after 19 and 43 years, respectively, communities of birds in clear-cuts of former coniferous plantations and selectively logged forests have not fully recovered from the disturbances of logging, highlighting the need to preserve primary forests for conservation of birds. 相似文献
20.
Dilip Chetry Rekha Medhi Jihosuo Biswas Debojit Das P. C. Bhattacharjee 《International journal of primatology》2003,24(2):383-388
Namdapha National Park and Tiger Reserve in the Changlang District of Arunachal Pradesh in northeastern India are rich in biodiversity. The dense evergreen forest of the park with high canopy coverage supports a variety of fauna including primates. In February, 2002, we surveyed the primates in Namdapha National Park to assess their status. We directly sighted, 5 species of diurnal primates, and secondary information shows the presence of stump-tailed macaques and slow lories. We encountered 10 groups of hoolock gibbons (33 individuals), 9 troops of capped langurs (61 individuals), 15 groups of Assam macaques (209 individuals), 6 groups of rhesus macaques (74 individuals) and one unidentified group of macaques (15 individuals). Hunting, rather than habitat destruction, is the chief potential threat for primates in the park. 相似文献