Habitat selection of four african treefrogs (Leptopelis boulengeri, Hyperolius fusciventris bourtoni, H. Guttulatus and Afrixalus dorsalis) in degraded environments of the Niger Delta, Nigeria

Abstract

The habitat structures of four species of African treefrogs (Leptopelis boulengeri, Hyperolius fusciventris bourtoni, H. guttulatus and Afrixalus dorsalis) in two degraded environments (Kwale and Patani) in the Niger Delta were investigated. There were a total of 381 individuals collected of which H. f. bourtoni was the most abundant species (173 individuals) at all sites while the least was L. boulengeri (41 individuals). Relatively even distribution of the treefrog species were observed at both study sites, however only L. boulengeri showed a significant difference (P< 0.05, df=1, x² = 5.488) among individuals at the two study sites. More female (195) individuals were recorded than males (186). Significantly more individuals of treefrog species were observed during the rainy season than the dry season except in H. guttulatus (P > 0.05, df =1, x² = 27.520) which was not significant. L. boulengeri occurred mainly in high elevations on the leaves and branches of shrubs and trees and were mainly seen in elevations between 3.1-≥4m above the ground level. H. f. bourtoni were sighted mostly from the leaves of grasses between 0.3-0.6m. Majority of H. guttulatus occupied leaves of shrubs and trees between 0.7-1.6m and a large number of individuals were collected from the roots of Pistia stratiotes submerged under water during the dry season. A. dorsalis occupied the lowest altitude among the species studied as many individuals were found between 0.08-0.4m on the leaves of grasses above water. L. boulengeri had the highest mean SVL and weight of 5.02±0.71cm and 8.93±0.91g respectively while H. f. bourtoni had the smallest of 2.30±0.31cm and 1.11±0.14g respectively. Female specimens were generally larger than males. Degraded secondary habitats offer a variety of microhabitats which are effectively utilized by these treefrogs species thus reducing interspecific competition.

Keywords: African treefrogs, habitat destruction, morphology, microhabitats, competition