Diet comparison between rainforest and cave populations of Craugastor alfredi (Anura: Craugastoridae): does diet vary in contrasting habitats?

ABSTRACT

Information about interpopulational variation of diet is important for thoroughly understanding the ecological niche of a species, the possible attributes that have allowed it to live in different habitats and ecosystems (if it is the case) and the degree of dietary specialization. This study compared dietary composition and diversity, size of prey consumed and feeding intensity between two geographically proximate populations of Craugastor alfredi, inhabiting contrasting habitats: one located in a remnant tropical rainforest and the other population located within a cave entrance, in eastern Mexico. A total of 118 frogs (50 from rainforest and 68 from cave) were stomach-flushed and, from those, 86 had at least one prey item (42 from rainforest and 44 from cave). Consumption proportions of orthopterans differed between habitats, with frogs from the cave having higher importance values of this prey than frogs from the rainforest. Additionally, both dietary diversity and feeding intensity were higher in the rainforest population. It was concluded that the generalized diet of C. alfredi, besides the high consumption of orthopterans by the cave population, may have contributed to its success in cave entrances. Nonetheless, other non-feeding attributes like small body size, direct development and semiarboreality may also facilitate the use of rock crevices in caves for foraging and reproduction.

KEYWORDS:

• Anura
• Craugastor alfredi
• dietary diversity
• interpopulational variation
• Mexico

Acknowledgements

We thank D. Aportela-Cortés, L. Alcaide-Carpio, C. Ameneyro, F. Vázquez-Córzas, K. Yc-García, U. Hernández-Salinas, C. Berriozabal-Islas, L. Hernández-Ayotla, S. Sánchez-Silva, T. Gutiérrez-Santillán, J. Valencia-Herverth and L. Fernández-Badillo for their field assistance. An early version of the manuscript was reviewed by V. Mata-Silva and D. DeSantis and two anonymous reviewers provided valuable comments. We are indebted to the authorities and local people from Tlacotepec de Porfirio Díaz, for making facilities available during our visits to the region. RLM acknowledges a graduate scholarship from CONACyT (No. 367157).

Disclosure statement

No potential conflict of interest was reported by the authors.

Geolocation Information

This research was conducted at two nearby locations in San Sebastian Tlacotepec, Puebla, Mexico, a fragment of rainforest (18.4047°N, −96.8452°W), and the entrance of a cave (18.4397°N, −96.8536°W).