Diet of Dendropsophus microcephalus and Scarthyla vigilans (Anura: Hylidae) at a locality in north-western Venezuela with notes on microhabitat occupation

Abstract

The coexistence of species with similar ecological requirements (food, space, time) has typically drawn attention of researchers because competition for resources is expected to be high. The diet and microhabitat occupation of two morphologically and ecologically similar species of Hylidae (Anura), Dendropsophus microcephalus and Scarthyla vigilans, were analyzed at a locality in northwestern Venezuela, with the aim of addressing the potential for space and food competition between them. Diet was estimated through the analysis of stomach contents and microhabitat occupation was estimated through recordings of perch type, height and horizontal distance to water. Thirty-six prey categories (32 families, 4 orders) of arthropods were identified: 30 categories in D. microcephalus and 21 categories in S. vigilans. The most important prey (RII) in D. microcephalus were Agelenidae (11.1%), Tachinidae (9.32%) and Lepidoptera-larvae (7.96%). Gryllidae (14.13%), Cicadidae (9.1%), Cicadellidae (8.3%) and Delphacidae (8.02%) were the most important in S. vigilans. Diet overlap was relatively low (0.32). Both species have relatively generalist diets. Both species occupied the same type of perches (leaves and stems of Dicotyledons and Monocotyledons) and heights (average: S. vigilans, 24 ± 16.2 cm; D. microcephalus, 22.7 ± 9.5 cm). The potential for space competition is high if perches are limited and food competition is expected to be low.