Ecological niche and aspects of the natural history of Phyllomedusa azurea (Anura: Hylidae, Phyllomedusinae) in the Cerrado of Central Brazil

Abstract

Aspects of the ecology and natural history of Phyllomedusa azurea were investigated in an area of Central Brazilian Cerrado between April, 2006, and February, 2007. Observations were conducted between 6:00 PM and 5:00 AM. The study focused on spatial, temporal, and trophic niches, morphometry and reproduction. Most animals were recorded vocalizing in places dominated by herbaceous vegetation and an open canopy. The main substrates used were bushes and trees, and animals were seen perched most often between 0.5 and 1.0 m of height. Spatial niche breadth was 2.91 and 3.83 for substrate and perch height, respectively. Most animal were sighted close to lentic water bodies, usually up to 0.50 m. It is possible that these characteristics are related primarily to the phylogeny of the genus and secondarily to the specific needs of the species and the local availability of resources. The bushes and trees were used by the species mainly as sites of vocalization and oviposition. Specimens of Phyllomedusa azurea was sighted most frequently between 8:00 PM and 9:00 PM. Estimated temporal niche breadth (activity period) was 4.68. Prolonged reproductive pattern was also observed predominantly in the months with higher temperature and higher humidity (September to February). The diet consisted of eleven items. The most important prey taxon for the females was Orthoptera (IVI = 63), whereas for the males, it was Araneae (IVI = 33). The breadths numeric and volumetric of the trophic niche, was respectively 1.80 and 1.16, for females, and 4.03 and 3.92, for males. Males and females differed in size (SVL) and mass, with the females being larger and heavier. The sizes of smaller reproductive individuals males and females were 34.64 and 40.33 mm, respectively. Differences in size may be related to different investments in reproduction by the two sexes.