Comments On "Predictive Modelling Of Patch Use By Terrestrial Herbivores" [chapter]

Ignas M. A. HeitkÖnig, Michael Drescher, Willem F. De Boer
2008 Resource Ecology  
Fryxell's aim (Chapter 6) is to evaluate the current understanding of forage intake and patch selection by herbivores across temporal and spatial scales, where resource (food) heterogeneity is large. His approach starts at a description of the functional response, i.e., the food intake response of consumers to quantitative changes in the resource supply. Re-developing several models of food and energy intake applicable at the detailed level of feeding station, he places bite size or bite
more » ... ing central to short-term food procurement. This is then developed into longer-term (daily) food or energy intake functions, where digestive rather than bite-size or bite-processing constraints may operate. In developing both instantaneous-and daily-intake functions, he makes use of so-called multiple piecewise formulas. Essentially, they read as minimising functions, where the objective function, i.e., food or energy intake in the short or the long term, is the minimum of either summed bite size, summed bite procurement, or digestion (long-term only) achieved. For instance, daily energy intake can be calculated as the intake of lab-determined energy from ramets over one day of feeding, or as the energy intake from ingestive processes, or as the energy intake of lab-determined total daily food, the latter subject to digestive constraints. If the energy intake calculated from, say, daily food digested is lower than any of the other calculated intake values, then digestion is considered to be the rate-determining
doi:10.1007/978-1-4020-6850-8_11 fatcat:6sglfmpkmjcdndjmvo5tbn7dza