Calling Site Selection by the South American Tree-FrogHypsiboas pulchellus(Anura, Hylidae) in Subtropical Wetlands

Abstract

Abstract. The selection of appropriate calling sites is a key aspect in the reproductive strategy of nearly all anurans. We evaluated if males of the South American tree frog (Hypsiboas pulchellus) select calling sites in undisturbed subtropical wetlands based on specific habitat cues. The study was designed to represent a snapshot of the male calling activity under low densities of intra- and interspecific competitors and little variation of climatic conditions. We characterized calling sites by measuring the vegetation attributes and flood levels of calling sites occupied by 59 males and comparing them to available microhabitats. We found that males exhibit some degree of selectivity for calling sites, often selecting microhabitats with greater density of vegetation < 50 cm tall. Calling site selection was not affected by water depth or area flooded. Most individuals vocalized in sites near the ground (≤ 25 cm), a pattern that is the contrary to that expected to maximize sound propagation. We suggest th...