THE ENERGETICS OF COPROPHAGY - A THEORETICAL-ANALYSIS

Lagomorphs, many rodents and some other small mammals eat their faeces during the part of the day when they are not foraging for fresh food. One of the possible benefits of this habit of coprophagy is that it m ay enable them to extract more energy from their food. A computer mode l is used to assess the likely benefits and explore their relationship s to food, feeding rate and gut morphology. The predicted benefits are much larger for hindgut fermenters than for foregut fermenters, and e specially large for hindgut fermenters with relatively small fermentat ion chambers. They are larger for poor foods (with lower proportions o f cell contents) than far richer ones. At low feeding rates the energe tic advantage of coprophagy may disappear if the faeces from food eate n during one feeding period emerge largely during the next, but this c an be avoided by adjusting the rate of passage of gut contents during the intervening rest period.