The scaling of feeding rate in wild primates: a preliminary analysis

Abstract

Shipley et al. (1994) theoretically and empirically demonstrated that the maximum feeding rate of mammalian herbivores (mainly ungulates) is largely determined by morphological factors and ultimately by body mass. By using values from the published literature, I conducted the scaling of 2 indices of feeding rate with body mass in wild primates: (1) the maximum and (2) the mean of dry weight intake rate (g/min) of different food items. The maximum feeding rate scaled with body weight to the power of nine-tenths to one. Body mass accounted for 57% to 71% of the variance in maximum feeding rate. Compared with Shipley et al.’s (1994) regression equation, primates exhibit a higher maximum feeding rate than ungulates of the same body mass. This might be due to the frugivorous nature of the primate diet. Further, the average feeding rate also scaled with body weight to the power of one-half to seven-tenths. Body mass accounted for 34% to 40% of the variance in average feeding rate. The observed body mass-dependent average feeding rate is due not only to the morphological constraints of small body mass but also to the selection of a diet with a higher feeding rate in large-bodied primates.