Abstract

Changes in digestive enzyme activity along the intestine may be related to changes in substrate concentration in the intestine. We examined the distribution of digestive enzymes along the intestine in two species of carnivorous passerine birds from the genus Cinclodes. Both species lacked sucrase activity, suggesting that these species are unable to feed on sucrose-rich diets. Distribution of maltase and aminopeptidase-N activity differed from that found in other passerines, including omnivorous species, but resembled those found in herbivorous and frugivorous birds. We hypothesize that the type of prey items that Cinclodes consume may explain the pattern of maltase and aminopeptidase-N expression.