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Animals that occupy stable home ranges tend to unevenly exploit different areas in their efforts to find fitness-limiting resources, while also reducing the risks of intergroup conflict. Most analyses of these extrinsic forces identify their effects on movement paths and home range geometry, but not on the interaction of these responses or how movements might be centrally constrained as a result of competition with neighbors. The range utilization slope is a measure of central tendency and consists of space use plotted against distance from the center of the range. Slopes tend to be linear, concave-up, or concave-down and are predicted to change as a function of feeding competition from neighbors. To test this prediction and determine the spatio-temporal scales over which the central tendency might vary, we calculated utilization slopes and an index of range overlap for grey-cheeked mangabeys (Lophocebus albigena), blue monkeys (Cercopithecus mitis), and red-tailed monkeys (C. ascanius) in Uganda, which consume similar diets but experience varying intensities of intergroup conflict. As predicted, we find variation in utilization slopes across and within species, which corresponds with the extent of range overlap among conspecific groups.
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Constraints on population growth of blue monkeys (Cercopithecus mitis) in Kibale National Park, Uganda
Abstract Changes in population size are driven by environmental and social factors. In spite of repeated efforts to identify the constraints on an unusually low-density population of blue monkeys ( Cercopithecus mitis ), it remains unclear why this generalist species fails to thrive in Kibale National Park in Uganda. While an unidentified disease may occasionally obstruct conception, it does not seem to limit overall reproductive rates. Infanticide at this site is infrequent due to the long tenures of resident males. Our analyses indicate that the single biggest constraint on blue monkey densities may be feeding competition with grey-cheeked mangabeys ( Lophocebus albigena ): across Kibale, the densities of these two species are strongly and negatively correlated. Though further analysis is needed to understand the timing and strength of feeding competition between them, we conclude that blue monkeys at Ngogo experience competitive exclusion from grey-cheeked mangabeys, possibly resolving the 50-year mystery surrounding this population.
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- PAR ID:
- 10349948
- Date Published:
- Journal Name:
- Behaviour
- Volume:
- 159
- Issue:
- 10
- ISSN:
- 0005-7959
- Page Range / eLocation ID:
- 961 to 987
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1163/1568539X-bja10160
