Sex differences in vertebrate spatial abilities are typically interpreted under the adaptive specialization hypothesis, which posits that male reproductive success is linked to larger home ranges and better navigational skills. The androgen spillover hypothesis counters that enhanced male spatial performance may be a byproduct of higher androgen levels. Animal groups that include species where females are expected to outperform males based on life-history traits are key for disentangling these hypotheses. We investigated the association between sex differences in reproductive strategies, spatial behavior, and androgen levels in three species of poison frogs. We tracked individuals in natural environments to show that contrasting parental sex roles shape sex differences in space use, where the sex performing parental duties shows wider-ranging movements. We then translocated frogs from their home areas to test their navigational performance and found that the caring sex outperformed the non-caring sex only in one out of three species. In addition, males across species displayed more explorative behavior than females and androgen levels correlated with explorative behavior and homing accuracy. Overall, we reveal that poison frog reproductive strategies shape movement patterns but not necessarily navigational performance. Together this work suggests that prevailing adaptive hypotheses provide an incomplete explanation of sex differences in spatial abilities.

The tadpoles of the Neotropical genus Atelopus are only known for 26 out of 96 species described. Here, we describe the tadpoles of A. elegans and A. palmatus including ontogenetic information, measurements, and images of individuals in several stages of growth. Both species are compared with their congeners taking into account some relevant features such as the coloration and relative measurements. Our description focuses on the abdominal sucker and mouth by providing scanning electron microscopy images and comparing the suctorial mechanism with other groups of anurans and fish. We also provide an update to knowledge of the abdominal suckers, and information about their lateral line system and the distribution of their lateral line openings. The results show that brown marks over a tan surface and an irregular distribution of marks along the body and tail are unique to A. elegans; while a patterned distribution of contrasting marks, and the presence of submarginal papillae are unique to A. palmatus. Also, both species show differences in the structures of their teeth. Finally, we conclude that some characters such as coloration, presence or absence of some structures, and relative measurements are useful for identifying the species. RESUMENLos renacuajos del género neotropical Atelopus se conocen para solamente 26 de un total de 96 especies descritas. Aquí, describimos los renacuajos de A. elegans y A. palmatus incluyendo su información ontogénica, mediciones e imágenes de individuos en varias etapas de desarrollo. Ambas especies se comparan con sus congéneres teniendo en cuenta algunas características relevantes como la coloración y las medidas relativas. Nuestra descripción se enfoca en la ventosa abdominal y la boca al proporcionar imágenes de microscopía electrónica de barrido y al comparar el mecanismo de succión con otros grupos de anuros y peces. Además, proveemos una actualización del conocimiento de las ventosas abdominales, e información sobre su sistema de línea lateral y la distribución de los orificios de la línea lateral. Los resultados muestran que las marcas marrones sobre una superficie marrón y una distribución irregular de marcas a lo largo del cuerpo y la cola son exclusivas de A. elegans; mientras que una distribución con patrones de marcas contrastantes y la presencia de una papila submarginal son exclusivas de A. palmatus. Además, ambas especies muestran diferencias en las estructuras de sus dientes. Finalmente, llegamos a la conclusión de que algunos caracteres como la coloración, presencia o ausencia de algunas estructuras y medidas relativas son útiles para identificar las especies. ARTICLE HISTORY

Sex differences in vertebrate spatial abilities are typically interpreted under the adaptive specialization hypothesis, which posits that male reproductive success is linked to larger home ranges and better navigational skills. The androgen spillover hypothesis counters that enhanced male spatial performance may be a byproduct of higher androgen levels. Animal groups that include species where females are expected to outperform males based on life-history traits are key for disentangling these hypotheses. We investigated the association between sex differences in reproductive strategies, spatial behavior, and androgen levels in three species of poison frogs. We tracked individuals in natural environments to show that contrasting parental sex roles shape sex differences in space use, where the sex performing parental duties shows wider-ranging movements. We then translocated frogs from their home areas to test their navigational performance and found that the caring sex outperformed the non-caring sex only in one out of three species. In addition, males across species displayed more explorative behavior than females. Furthermore, androgen levels correlated with explorative behavior and homing accuracy. Our findings suggest that poison frog reproductive strategies shape space use patterns but not navigational performance, providing counterevidence to the prevailing view of adaptive sex differences in spatial abilities.