The gut microbiome is important for host health and can be influenced by environmental and hormonal changes. We studied the interactions between anthropogenic land use, glucocorticoid hormones, and gut bacterial communities in common toads (Bufo bufo). We sampled tadpoles from ponds of three habitat types (natural, agricultural, and urban ponds), examined gut microbiome composition using amplicon sequencing of the 16S rRNA gene, and measured the associated stress physiology using water-borne hormones. Tadpoles from different habitat types significantly differed in bacterial composition. However, bacterial richness, Shannon diversity, and Firmicutes to Bacteroidota ratio did not vary with habitat type. In contrast with other studies, we found a positive correlation between baseline corticosterone release rate and bacterial diversity. Stress response and negative feedback were not significantly correlated with bacterial diversity. These results suggest that, despite alterations in the composition of intestinal bacterial communities due to land-use change, common toad tadpoles in anthropogenic habitats may maintain their physiological health in terms of the “gut-brain axis”.

Documentamos una hembra de Chrotopterus auritus en estado de lactancia con su cría presente en la parte ventral de su cuerpo. El espécimen fue capturado con una trampa de arpa en un bosque tropical húmedo de la costa del Pacífico de Guatemala, dentro de la reserva natural privada Finca Patrocinio, Quetzaltenango, Guatemala el 29 de mayo de 2017. Hay poca información sobre la biología de esta especie, especialmente en Guatemala, lo que refleja la importancia de nuevos estudios sobre el comportamiento silvestre de esta especie.

-The black-eyed leaf frog (Agalychnis moreletii) is a critically endangered hylid frog restricted to humid lowland and lower montane forests of southern Mexico and northern Central America. Very few reports exist on wild reproductive behavior of this species. Lower body tremulation display has been reported as a relevant part of agonistic interactions between males of the related species A. callidryas but has never been reported in other species of Agalychnis. Herein, we present the first report and description of this tremulation display among males of A. moreletii in a lower montane forest of Guatemala. Based on our observations, we suggest that this display may serve to prevent physical confrontations among males and might play an important role in defining territories. We also suggest that the difference in fundamental frequency of the tremulations between A. moreletii and A. callidryas may serve to avoid confusing signals between species where they breed sympatrically.