Effects of environmental factors on the ecology and survival of a widespread, endemic Cerrado frog

• Published in: Biotropica 2023-03, Vol.55 (2), p.551-562
• Main Authors: Fiorillo, Bruno F., Faggioni, Gabriel Paganini, Cerezer, Felipe Osmari, Becker, C. Guilherme, Díaz‐Ricaurte, Juan C., Martins, Marcio
• Format: Article
• Language: English
• Subjects: Abundance; Amphibians; Aquatic reptiles; Body size; Breeding sites; Ecological effects; Environmental effects; Environmental factors; Ephemeral water bodies; Fauna; Frogs; Grasslands; habitat; Habitat changes; Habitat loss; Habitat selection; Habitat utilization; Habitats; Harbors; Heterogeneity; Land cover; mark–recapture; Metapopulations; Mortality; Physalaemus nattereri; Population number; Sampling; savanna; Savannahs; Survival; Vegetation; vegetation heterogeneity; Vegetation type; Vertebrates; Woodlands
• ISSN: 0006-3606; 1744-7429
• DOI: 10.1111/btp.13209

Understanding the mechanisms that affect habitat use by vertebrates is critical for understanding how species are distributed across landscapes and how they cope with habitat change. The Brazilian Savanna (the Cerrado) has vegetation ranging from grassland to woodland savannas and harbors a rich and diverse amphibian fauna impacted by accelerated habitat loss. Here, we test the influence of vegetation type (from grassy scrubland to woodland) and distance from breeding sites (ephemeral water bodies) on body size, abundance, and survival of the frog Physalaemus nattereri in a natural metapopulation system of south‐central Brazil. We also test whether body size is a significant predictor of population abundance. We found that the abundance of P. nattereri varies according to the mean snout–vent length of each metapopulation (sampling unit), as well as a higher estimated mortality rate in woodlands compared with typical Cerrado. Furthermore, we found no difference in estimated mortality among sampling units located far or close to ephemeral water bodies. Thus, our results highlight variable responses of P. nattereri metapopulations to environmental factors, despite the observed high heterogeneity among sampled habitats and the importance of ephemeral water bodies for reproduction. These findings highlight that land cover and availability of breeding sites might not always interact to explain population persistence of Cerrado frogs. RESUMO Compreender os mecanismos que afetam o uso do habitat por vertebrados é fundamental para entender como as espécies estão distribuídas em paisagens e como elas lidam com a mudança desses habitats. A vegetação da savana Brasileira (o Cerrado) varia de campos a savanas arbóreas e abriga uma rica e diversa fauna de anfíbios que é impactada pela perda acelerada de habitat. Aqui, nós testamos a influência do tipo de vegetação (do cerrado à floresta) e da distância dos sítios de reprodução (corpos d’água efêmeros) no tamanho do corpo, abundância e sobrevivência de Physalaemus nattereri, em um sistema de metapopulações natural do centro‐sul do Brasil. Também testamos se o tamanho do corpo é um preditor significativo da abundância populacional. Descobrimos que a abundância de P. nattereri varia de acordo com o comprimento rostro‐cloacal médio de cada metapopulação (unidade amostral) e que há uma maior taxa de mortalidade estimada em áreas florestais em comparação ao cerrado típico. Além disso, não encontramos diferença na mortalidade