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Daily Travel Distance (daily + travel_distance)

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Life Sciences100%

Selected Abstracts

Links between habitat degradation, and social group size, ranging, fecundity, and parasite prevalence in the Tana River mangabey (Cercocebus galeritus)

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009
David N.M. Mbora
Abstract We investigated the effects of anthropogenic habitat degradation on group size, ranging, fecundity, and parasite dynamics in four groups of the Tana River mangabey (Cercocebus galeritus). Two groups occupied a forest disturbed by human activities, while the other two occupied a forest with no human disturbance. We predicted that the groups in the disturbed forest would be smaller, travel longer distances daily, and have larger home ranges due to low food tree abundance. Consequently, these groups would have lower fecundity and higher parasite prevalence and richness (number of parasite species). We measured the abundance of food trees and anthropogenic activity in the forests, the groups' daily travel distances and home range sizes, and censused social groups over 12 months. We also analyzed fecal samples for gastrointestinal parasites from three of the groups. The disturbed forest had a lower abundance of food trees, and groups in this forest traveled longer distances, had larger home range sizes, were smaller, and had lower fecundity. The groups in the disturbed forest had higher, although not statistically significant, parasite prevalence and richness. This study contributes to a better understanding of how anthropogenic habitat change influences fecundity and parasite infections in primates. Our results also emphasize the strong influence of habitat quality in determining daily travel distance and home range size in primates. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source]

Influence of day length, ambient temperature, and seasonality on daily travel distance in the Yunnan snub-nosed monkey at Jinsichang, Yunnan, China

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 3 2009
Ren Baoping
Abstract This article examines the effect of ambient temperature, day length, weather conditions, and seasonality on daily path length (DPL) of a free-ranging group of Yunnan snub-nosed monkeys (Rhinopithecus bieti) using an auto-released GPS collar. Data were collected from December 17, 2003 to October 22, 2004 at Laojunshan in northwestern Yunnan province, China. The average DPL of the monkey group was 909±472,m (n=291), with the shortest distance being 180,m and the longest distance 3,626,m. Ambient temperature and day length were found to affect DPL. Both factors were positively correlated with DPL, which means that the monkey group traveled greater distances on longer and warmer days. At the study site, three distinct seasons were identified, and DPL did not vary significantly across these periods. The time of sunrise was not correlated with DPL. Nevertheless, we sometimes observed the group starting its daily trip later on cloudy days than on sunny days. Furthermore, weather conditions (e.g. rainy, cloudy, and sunny) did not influence the average DPL of the study group. Overall we found that the primary factors affecting DPL in R. bieti were day length and ambient temperature, especially daily highest temperature. Am. J. Primatol. 71:233,241, 2009. © 2008 Wiley-Liss, Inc. [source]

Do competitive intraguild interactions affect space and habitat use by small carnivores in a forested landscape?

ECOGRAPHY, Issue 4 2006
Caroline St-Pierre
Complex interactions such as interference competition and predation, including intraguild predation, are now recognized as important components in animal community structure. At the lower end of a guild, weasels may be highly affected by other guild members due to small body size in relation to other predators. In 2000 and 2001, we radio-collared 24 ermines Mustela erminea and 25 long-tailed weasels M. frenata in 2 areas that differed in abundance of guild members. We tested the hypothesis that when faced with an increased density of other guild members, weasels would modify space and habitat use to reduce the risk of predation associated with encounters involving guild members. We predicted that weasels would increase use of specific habitats (such as refuges) to reduce encounter rates in the presence of a greater number of guild members. Because M. erminea is smaller than M. frenata and thus better able to take advantage of small rodent burrows as refuges from predators and as feeding grounds, we also predicted that M. frenata would show a stronger response to a higher abundance of guild members than M. erminea. Results were consistent with our predictions. Faced with an increased abundance of guild members, M. frenata showed increased habitat selectivity and reduced activity levels, which resulted in increased daily travel distances and increased home ranges. Mustela erminea responded to an increased abundance of guild members through reduced use of preferred habitat which M. frenata already occupied. The contrasting pattern of habitat selection observed between the 2 mustelid species suggested cascading effects, whereby large-predator pressure on M. frenata relaxed pressure of M. frenata on M. erminea. Our results draw attention to the likelihood that competitive intraguild interactions play a facilitating role in M. erminea,M. frenata coexistence. [source]

Links between habitat degradation, and social group size, ranging, fecundity, and parasite prevalence in the Tana River mangabey (Cercocebus galeritus)

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009
David N.M. Mbora
Abstract We investigated the effects of anthropogenic habitat degradation on group size, ranging, fecundity, and parasite dynamics in four groups of the Tana River mangabey (Cercocebus galeritus). Two groups occupied a forest disturbed by human activities, while the other two occupied a forest with no human disturbance. We predicted that the groups in the disturbed forest would be smaller, travel longer distances daily, and have larger home ranges due to low food tree abundance. Consequently, these groups would have lower fecundity and higher parasite prevalence and richness (number of parasite species). We measured the abundance of food trees and anthropogenic activity in the forests, the groups' daily travel distances and home range sizes, and censused social groups over 12 months. We also analyzed fecal samples for gastrointestinal parasites from three of the groups. The disturbed forest had a lower abundance of food trees, and groups in this forest traveled longer distances, had larger home range sizes, were smaller, and had lower fecundity. The groups in the disturbed forest had higher, although not statistically significant, parasite prevalence and richness. This study contributes to a better understanding of how anthropogenic habitat change influences fecundity and parasite infections in primates. Our results also emphasize the strong influence of habitat quality in determining daily travel distance and home range size in primates. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source]