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Copyright of African Journal of Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Conservationists are raising concerns over high lion Panthera leo mortality and prey population declines in the area at the frontier between the Democratic Republic of Congo and Uganda. Confirming if threats to lions are severe or lion populations are disappearing requires extensive surveys on the ground because aerial detection of lions is inaccurate. Yet, ground surveys over large areas are unsafe or infeasible in the war-torn study area. We used aerial surveys of medium- to large-bodied ungulate prey to estimate lion abundance in two adjoining parks: Queen Elizabeth National Park, Uganda, and Parc National des Virunga, Democratic Republic of Congo. We validated two approaches to predict lion abundance using total counts of lions from Uganda. From this, we predict the two national parks together could have held 221 lions in 2004 and they have the potential to hold 905 lions if prey recover and lion-specific mortality is curbed. This makes the region a potential stronghold for the species in central Africa. However, a recent one third decline in lion numbers in the Ugandan Park and pervasive threats to the Congolese Park lead us to recommend immediate conservation intervention for lions and their prey. In Uganda, we recommend focused action to protect lions from poaching and retaliation, whereas in Congo, general enforcement of wildlife protection and a ground-based survey for lions are needed. [ABSTRACT FROM AUTHOR]

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A central issue in socioecology is the nature of the relationship between an organism's environment and its social structure. In chimpanzees, the fission-fusion social system is thought to minimize feeding competition for primary dietary components: ephemeral, dispersed patches of ripe fruit. Intragroup feeding competition is thought to force individuals into small parties. Informal observations in the Sonso region of the Budongo forest had suggested that in this habitat, food supply was such that feeding competition was less important in determining grouping patterns than elsewhere. We used data collected on food supply and party sizes over a 4-year period to investigate this suggestion. In accord with theoretical expectation, sizes of foraging parties fluctuated with the size of food patches. However, party sizes showed either negative or no relationship with habitat-wide measures of food abundance. Likewise party sizes showed little relationship to overall measures of food dispersion. For important dietary items, both fruit and leaves had patchy distributions, though the degree of clumping was not strong, and fruit was not more clumped than leaves. Generally, abundant food appeared to be less patchy, and chimpanzees appeared to use more patches as food became more abundant rather than forming larger parties. We suggest that both dispersal and abundance need to be considered when investigating the impact of food supply on grouping patterns, and that the importance of food as a factor in determining chimpanzee grouping patterns declines with increasing levels of abundance. [ABSTRACT FROM AUTHOR]