Habitat and dietary differences between Gorilla gorilla gorilla and Gorilla gorilla beringei : implication for social variability

In this thesis I examine and synthesize the research literature on the habitats, diets and behaviors of Gorilla gorilla beringei (mountain gorilla) and Gorilla gorilla gorilla (western lowland gorilla). Sympatric chimpanzees and the eastern lowland gorilla habitat, diet and behaviors are introduc...

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Bibliographic Details
Main Author: Bate, Jacklyn C.
Language:English
Published: 2009
Online Access:http://hdl.handle.net/2429/15393
Description
Summary:In this thesis I examine and synthesize the research literature on the habitats, diets and behaviors of Gorilla gorilla beringei (mountain gorilla) and Gorilla gorilla gorilla (western lowland gorilla). Sympatric chimpanzees and the eastern lowland gorilla habitat, diet and behaviors are introduced when they elaborate significant aspects of Gorilla gorilla beringei or Gorilla gorilla gorilla. The contrasting habitats, diets, ecological adaptations and behavioral consequences among the gorilla subspecies are rationalized in relation to Wrangham's 1980 ecological model and the socio-ecological model, e.g., of 1997 as stated by Sterck and co researchers. Habitat, dietary and behavioral differences between the western lowland gorilla and the mountain gorilla calls into question the use of the mountain gorilla social system as a norm for all gorilla subspecies. However, problems in contrasting and examining the differences among the subspecies is heightened by a lack of long term behavioral studies on the western lowland gorilla, the numerically largest subspecies. Lack of habituation, visibility and tracking in aquatic herbal feeding sites have hindered behavioral studies of Gorilla gorilla gorilla. Significant issues are raised in relation to the risk of infanticide as a primary mechanism for female gregariousness across all gorilla subspecies. Moreover, the gorilla (primate) social system as delineated by Keppeler and van Schaik in 2002 demonstrates that other important areas of sociality (e.g., group cohesiveness) differ among the subspecies Additionally, annotations o f selected literature that apply to the subspecies' ecological issues (i.e., dietary and habitat particulars) with emphasis on the western lowland gorilla are presented as a baseline of ecological comparisons and research balance. Within the present data, although sociality and behaviors differ among the gorilla subspecies, the primary behavioral characteristics (e.g., female and male natal group dispersal) of each social system are similar. The caveat is the need for behavior studies of western lowland gorilla that are based on direct observation and not primarily indirect observation. Without such research the theory and behavioral characteristics of the mountain gorilla become the social system and theoretical basis of the western lowland gorilla despite the habitat, dietary and behavioral variations across the gorilla subspecies.