Wildfact Library

[Sully]

On herbivore classification

"Hofmann and Stewart (1972) classified as: 1) Bulk and Roughage Feeders or Grazers that select diets containing < 25% browse; 2) Concentrate Selectors or Browsers that select diets containing at least 75% fruits, dicot foliage, and tree and shrub stems and foliage; or 3) Intermediate or Mixed Feeders that select both grasses and browses.  Using this scheme to classify 65 ruminants on 4 continents, Hofmann (1989) found that 25% were grazers, 40% were browser/fruit-eaters, and 35% were mixed feeders.  Many have argued that tree and shrub foliage and stems should not be considered “concentrates”, because they are heavily defended by plant secondary compounds (Robbins et al. 1995) and lignin, and thus fruit selectors (true concentrates) and browsers should form separate categories (Bodmer 1990).  Others suggest that these categories only reflect trends in body mass, because smaller herbivores tend to select concentrates whereas larger ones tend to choose roughage or grass (Gordon and Illius 1994, Robbins et al. 1995).  For example, in tropical areas frugivores average 24 kg, browsers 394 kg, intermediate feeders 695 kg, and Grazers 670 Kg (Bodmer 1990)."

from:

Grazers and Browsers: How Digestive Morphology Affects Diet Selection Reply