Literaturdatenbank
Literaturdatenbank |
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Bjorndal, K. A. (1989). Flexibility of digestive responses in two generalist herbivores, the tortoises geochelone carbonaria and geochelone denticulata. Oecologia, 78(3), 317–321.
Added by: Admin (23 Aug 2008 19:57:42 UTC) Last edited by: Beate Pfau (22 Aug 2009 08:41:22 UTC) |
| Resource type: Journal Article DOI: 10.1007/BF00379104 BibTeX citation key: Bjorndal1989b View all bibliographic details  |
Categories: General Keywords: Chelonoidis, Chelonoidis carbonaria, Chelonoidis denticulata, Ernährung = nutrition, Geochelone, Physiologie = physiology, Schildkröten = turtles + tortoises, Testudinidae Creators: Bjorndal Collection: Oecologia |
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| Abstract |
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Testudinidae Geochelone carbonaria denticulata Summary To test the prediction that digestive responses digestibility, intake and passage time-of generalist herbivores vary with different diets, feeding trials were conducted in Venezuela with two sympatric tortoise species, Geochelone carbonaria and G. denticulata. Three single-species diets (two fruit, one foliage) were fed to both species. For a given diet, digestibility, mass-specific intake and passage time did not differ between the two tortoise species, nor did they vary by sex or body mass within each species. However, the digestive parameters varied for tortoises feeding on the different diets. The responses ranged from nearly abandoning cell wall fermentation and depending entirely on extraction of cell contents to relying heavily on cell wall fermentation. Therefore, these generalist herbivores have flexible digestive responses that are influenced by diet, not fixed digestive responses that limit the diet, as previously observed in other generalist herbivores. A three-part classification of herbivores (specialist, specialized mixed feeder and opportunistic mixed feeder) is suggested as an approach to understanding flexible and inflexible digestive strategies in herbivores. Added by: Admin Last edited by: Beate Pfau |