ISSN:0275-2565    

DOI:10.1002/ajp.1350210202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThis review examines the diversity of avian mixed foraging flocks with the goal of relating the conclusions to primate polyspecific associations. Mixed associations are considered as adaptations for achieving an optimal balance between predator protection and feeding efficiency. In open habitat, predator and prey are able to detect each other at a distance and feeding competition is low, especially in species that subsist on a homogeneously distributed food supply. These conditions favor large groups of variable composition. In closed habitats, predators attack at close range, so early warning alarm systems are at a premium. Feeding competition is often intense because food resources such as fruit, flushing leaves, and nectar are spatially concentrated. Since feeding competition is generally less between than within species, these conditions favor mixed associations composed of small numbers of several to many species, and the evolution of elaborate early warning systems to thwart predators. The primate polyspecific associations that have been studied to date share characteristics with the closed habitat model while exhibiting some important distinctions. Primate associations are made up of integral troops, not individuals, implying high incremental costs of joining. These costs, plus a paucity of ecologically compatible combinations of species, seem to limit primate polyspecific associations geographically to regions in which the presence of monkey‐eating raptors provides a strong incentive for aggregatio

ISSN:0275-2565    

DOI:10.1002/ajp.1350210203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractSympatric guenons in East Africa associate with one another in mixed‐species groups to an intermediate degree. This makes it possible to compare a given group's ecology and behavior when it is part of an association to when it is unaccompanied, and to correlate association tendency with various ecological parameters. Two studies incorporating these approaches have been made of sympatricCercopithecus ascaniusandC. mitismonkeys in the Kakamega Forest, Kenya, and the Kibale Forest, Uganda. The pattern of and reasons for association in each site are reviewed. Compared to Kakamega, association betweenC. ascaniusandC. mitisin Kibale occurs less often, and the species appear to benefit relative to one another in different ways. These results suggest that the particular ecological setting greatly influences the nature of the interaction between species, through its effect on population structure, dietary overlap, food distribution, and community composition. The major ecological differences between the two study areas probably reflect post‐Pleistocene history and possibly climate, but they have important consequences for the present‐day population structure and feeding ecology of each species, and hence affect relations between them as

ISSN:0275-2565    

DOI:10.1002/ajp.1350210204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThis study examined the social interactions between moustached tamarins,Saguinus mystax, and saddle‐back tamarins,Saguinus fuscicollis, living in a mixed‐species troop at the Río Blanco, Peruvian Amazonia, between July 1985 and July 1986. Mixed‐species troops were common among theS. mystaxandS. fuscicollispopulations in the Río Blanco study area; 72% of all sightings ofS. mystaxand 82% of all sightings ofS. fuscicolliswere in mixed‐speices troops (study group excluded from analysis). In the study group, the two species spent on average 82% of time in association. Interactions were observed at a rate of one per 5 h of observation. Most interactions (96%) were agonistic. About 70% of agonistic interactions occurred at small food resources (crown diameter<5 m and/or limited number of ripe fruits). Moustached tamarins were always dominant over saddle‐back tamarins. Friendly interactions were extremely rare and were restricted to play invitations. Mutual calling was observed in the morning before the two species joined each other and during the day when they became separated. It is concluded that interspecific interactions and mutual calling incur some costs to the associated species but that these costs

ISSN:0275-2565    

DOI:10.1002/ajp.1350210205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractClose association between olive colobus (Procolous verus) and other monkeys (especiallyCercopithecusspecies) has been observed throughout the range ofP. verusin the forest zone of West Africa. To investigate the basis of this association, we made new observations in Sierra Leone, concentrated at Tiwai Island. We obtained data on the association patterns of monkeys over a large area of the island from line‐transect samples, and studied association behavior via long‐term observational sampling of habituated groups of olive colobus and Diana monkeys (C. diana). During transect sampling, olive colobus always were seen less than 50 m from monkeys of other species, especiallyCercopithecus. In studies of habituated groups, we found that one groups of olive colobus associated closely with a larger groups of Diana monkeys for more than 3 years. Members of the two groups were within 50 m of each other on over 80% of scan samples; the two groups shared the same range, but foraged in different parts of the canopy and had little dietary overlap; association was maintained by the behavior of the colobus. The olive colobus was the only Tiwai monkey species seen less than 50 m from members of a secon Diana study group more frequently than expected, although in this case the two species were associated during less than 12% of samples. In both cases, we detected month‐to‐month variation in association frequency. We suggest that olive colobus has a strong tendency to associate with other monkeys as part of an evolved strategy; that observed association patterns depend on the ranging habits and group dispersion patterns of the other species in the area; and that this strategy evolved because it reduces predation risk for a small‐bodied monkey that forages in small, dispers

ISSN:0275-2565    

DOI:10.1002/ajp.1350210206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractShort‐term associations between primate species offer the opportunity to measure changes in individual behavior and ecology in response to alterations in group size and composition. During a three‐month study of associations between squirrel monkeys (Saimiri sciureus) and brown capuchin monkeys (Cebus apella) in Manu National Park, Peru, I measured resource use and feeding efficiency for both species when in mixed and solitary troops, as well as the context and outcome of competitive interactions.Saimiritraveled amongCebushome ranges and were periodically led byCebusto large fruiting and flowering trees. Feeding rates in large fruit trees were altered by the presence of the other species–positively forCebus, but negatively forSaimiri. Association increased the average diameter of the troop only forCebus, which could control access to small, concentrated resoures found while the mixed troop moved through the forest. Results of this short‐term study suggest that effects of association on resource use differ for the two species, and are related to the size of resources as well as to differences in body size and group size between the

ISSN:0275-2565    

DOI:10.1002/ajp.1350210207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractMixed‐species troops composed of two species of tamarin monkeys, and rarely other ceboids, occur throughout much of western Amazonia and are notable for their long‐term stability. This study identified several variables that appeared to promote mixed‐species troop cohesion and yet maintained spatial segregation between species. Three variables enhanced in terspecific spatial segregation: differences in support use, vertical stratification, and interindividual spacing. In contrast, early morning vocalizations and well‐coordinated movement patterns contribute to cohesion within a mixed‐species troop. The combination of these variables may help explain how two congeneric species accommodate one another with little apparent interspecific aggression.The exact nature of benefits and costs to each individual in a mixed troop is still elusive; however, a comparison of population densities of sympatric and allopatric tamarins suggests that population growth of one partner (Saguinus fuscicollis) is enhanced in the presence of a congeneri

ISSN:0275-2565    

DOI:10.1002/ajp.1350210208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0275-2565    

DOI:10.1002/ajp.1350210209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0275-2565    

DOI:10.1002/ajp.1350210210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0275-2565    

DOI:10.1002/ajp.1350210201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY