Food and feeding habits of some anuran species in south-western Nigeria
The food and feeding habits of some anuran species in south-western Nigeria were investigated. Individuals of eighteen anuran species were selected randomly from collection made from the various survey sites which represented all the anuran families observed in the study. Morphometric measurements and analysis of the stomach contents of these selected species were carried out. High occurrences were recorded for stomachs that were 25% and 50% full while lower occurrences were observed for those that were 75% and 100% full. Anuran species having the lowest percentage (12.5%) of empty stomachs was Amietophrynus maculatus while Phrynobatrachus latifrons had the highest percentage (41.7%) of empty stomach. The order Coleoptera constituted the largest occurrence of insects observed in the stomach of anurans followed by the order Hymenoptera. Larger prey organisms were observed in the diets of larger anuran species such as Amietophrynus maculatus and Hoplobatrachus occipitalis, but were absent in diets of smaller anuran species such as Phrynobatrachus latifrons and Arthroleptis variabilis. Fossorial species (Hemisus marmoratus and H. guineensis) had isopterans as their major food item where as arboreal species (Leptopelis boulengeri, L. hyloides and Hyperolius guttulatus) had high occurrences of ants, bees and wasps in their diets. The morphology and habitat of anuran species have to a large extent a great influence on the food and feeding habits of these species as most species observed were generalist or opportunistic feeders taking prey roughly in proportion to their abundance in the habitat.
Keywords: anuran, morphometric measurement, Coleoptera, Hymenoptera, generalist and opportunistic feeders.