Niche separation of black-and-white colobus monkeys (Colobus angolensis and Colobus guereza) in the Ituri Forest.
Item
-
Title
-
Niche separation of black-and-white colobus monkeys (Colobus angolensis and Colobus guereza) in the Ituri Forest.
-
Identifier
-
AAI9720076
-
identifier
-
9720076
-
Creator
-
Bocian, Carolyn Mary.
-
Contributor
-
Advisers: John Oates | Carol Simon
-
Date
-
1997
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Biology, Ecology | Psychology, Behavioral | Anthropology, Physical
-
Abstract
-
I studied the ecology and social organization of sympatric Colobus angolensis and C. guereza to test the hypothesis that basic species differences may explain their niche separation. Field work was conducted in the Okapi Wildlife Reserve, Central Ituri Forest, from late 1992 to early 1994. Systematic observation of study groups over a 12-month period examined food selection, habitat use, and ranging patterns. Census work was conducted in three forest types to determine patterns of local abundance. Analyses of food chemistry examined the relationship between food selection and specific chemical measures.;In most months, Colobus guereza was primarily folivorous; C. angolensis was less specialized. In contrast to C. angolensis, seed-eating by C. guereza seemed to be a compensatory response to young leaf scarcity. Leaf selection by C. angolensis was negatively correlated with fiber content; for C. guereza, no such correlation was found. Interspecific diet overlap was highest for two categories of foods: young leaves of rare deciduous trees, and seeds of common leguminous trees.;The species differed in their social organization and in patterns of range use. C. angolensis occurred in large, multi-male bisexual groups, and frequently formed temporary associations with other conspecific groups. The study group used a large home range which overlapped extensively with those of other groups. C. guereza formed smaller, bisexual groups, with one or two adult males. The study group used a much smaller range, within which one area was used intensively; range overlap with conspecific groups was low. C. angolensis ranging patterns were associated with food availability, while those of C. guereza were associated with the proximity of conspecific groups.;The study groups differed in habitat use. C. angolensis used closed-canopy forest much more than did C. guereza; guereza seemed to prefer open-canopy areas. Census results suggest that C. guereza may be twice as abundant in secondary forest than it is in mature mixed forest; the species is apparently rare in Gilbertiodendron-dominant forest. C. angolensis occur at similar densities in secondary and in mature mixed forest, but at lower densities in Gilbertiodendron forest.;Evidence from this study suggests that: (1) C. guereza shows a strong tendency toward folivory; this tendency may reflect a specialized ability to process leaf fiber; (2) Species differences in social organization may partially explain their differences in ranging patterns; such differences may lead to very different patterns of resource exploitation; (3) In sympatry, species differences in habitat use may reflect preferences for different forest types; (4) Basic species differences may be stronger determinants of Colobus niche separation than are interspecific interactions.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
