Reproductive biology of Melanophryniscus montevidensis (Anura: Bufonidae) from Uruguay: reproductive effort, fecundity, sex ratio and sexual size dimorphism

ABSTRACT

We analyzed the reproductive traits of a population of Melanophryniscus montevidensis. The reproductive events were associated to rainfalls. Males called from dawn to late night, were more abundant than females, and adopted alternative tactics to find partners (active search). Females were larger than males, and had mature oocytes and lipid reserves after spawning; they showed no association between size and fecundity. As an explosive breeder, females are prepared all year long for reproduction. Several individuals revealed high site-fidelity for breeding. Knowledge about breeding pattern could help to propose suitable and efficient in situ conservation measures for this endangered species.

Resumen

Analizamos las características reproductivas de una población de Melanophryniscus montevidensis. Los eventos reproductivos estuvieron asociado s a precipitaciones. Los machos vocalizaron desde el amanecer hasta entrada la noche, fueron más abundantes que las hembras y usaron tácticas alternativas para obtener parejas (búsqueda activa). Las hembras fueron más grandes que los machos, mantuvieron oocitos maduros y reservas lipídicas luego del desove y no mostraron asociación entre tamaño y fecundidad. Como reproductor explosivo, las hembras están listas todo el año para la reproducción. Varios individuos revelaron alta fidelidad al sitio de cría. El conocimiento del patrón reproductivo podría ayudar a proponer medidas adecuadas y eficientes para la conservación in situ de esta especie amenazada.

KEYWORDS:

• Melanophryniscus montevidensis
• breeding events
• reproductive parameters
• Uruguay

Acknowledgments

We are very grateful to Arley Camargo, Gabriel Francescoli and Susana González for their suggestions on an early version of this work. To Ernesto Elgue and Santiago Cruces for assisting in the use of Software Wild-ID; and to Federico Gallego for designing the maps. To Aline Vega for her valuable help in the translation of this study to its English version. We thank to the colleagues of “Laboratorio de Sistemática e Historia Natural de Vertebrados” and the park rangers of Laguna de Rocha for supporting our fieldwork.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental material

Supplemental data for this article can be accessed here.

Additional information

Funding

The authors acknowledge the financial support of Agencia Nacional de Investigación e Innovación (ANII) [FCE 2009_1_2514] and Programa de Desarrollo de las Ciencias Básicas (PEDECIBA). GP acknowledges ANII for the postgraduate scholarship and RM acknowledges SNI (ANII) for financial support.