Modelling the nutritional ecology of ungulate herbivores: evolution of body size and competitive interactions

摘要: A simulation model is used to quantify relationships between diet quality, digestive processes and body weight in ungulate herbivores. Retention time of food the tract shown by regression scale with W0.27, be longer ruminants than hindgut fermenters. Allometric whole gut mean retention (MRT, h) (W) were: MRT=9.4 W0.255 (r 2=0.80) for fermenters MRT=15.3 W0.251 2=0.76) ruminants. Longer ingesta large-bodied increases efficiency relative small animals permits them survive on lower-quality foods. Compared ruminants, fermenters' faster throughput an advantage which outweighs their lower efficiency, particularly poor quality foods, provided that resources are not limiting. This suggests predominance middle range weights results from more efficient use scarce under conditions resource depletion. Considering only physical limitations intake, shows allometric coefficient scales energy intake mass 0.88 0.82 The advantages large size countered disadvantages where quantity limited, we suggest upper limit determined ability extract nutrients feeding niches during nadir seasonal cycle abundance.