Biotic and abiotic sounds affect calling activity but not plasma testosterone levels in male frogs (Batrachyla taeniata) in the field and in captivity

Diversity of temporal response patterns in midbrain auditory neurons of frogs Batrachyla and its relevance for male vocal responses

We investigated response selectivities of single auditory neurons in the torus semicircularis of male frogs Batrachyla leptopus (72 neurons) and B. taeniata (57 neurons) to synthetic stimuli of different temporal structures. Series of stimuli in which note and pulse rate, note and pulse structure and call duration varied systematically were presented. Neuronal responses quantified in terms of proportions of units displaying diverse temporal transfer functions are related in different modes with patterns of evoked vocal responses studied previously in these frogs. Correspondences and mismatches occurred between the auditory and vocal domains. The analysis of this evidence together with corresponding information from previous neuronal and behavioral studies in the third species of this genus, B. antartandica, indicates that different modes of preferences for acoustic communication signals can coexist within this anuran group.

Androgen responsiveness to simulated territorial intrusions in Allobates femoralis males: Evidence supporting the challenge hypothesis in a territorial frog

Territoriality has been widely described across many animal taxa, where the acquisition and defence of a territory are critical for the fitness of an individual. Extensive evidence suggests that androgens are involved in the modulation of territorial behaviours in male vertebrates. Short-term increase of androgen following a territorial encounter appears to favour the outcome of a challenge. The "Challenge Hypothesis" proposed by Wingfield and colleagues outlines the existence of a positive feedback relationship between androgen and social challenges (e.g., territorial intrusions) in male vertebrates. Here we tested the challenge hypothesis in the highly territorial poison frog, Allobates femoralis, in its natural habitat by exposing males to simulated territorial intrusions in the form of acoustic playbacks. We quantified repeatedly androgen concentrations of individual males via a non-invasive water-borne sampling approach. Our results show that A. femoralis males exhibited a positive behavioural and androgenic response after being confronted to simulated territorial intrusions, providing support for the Challenge Hypothesis in a territorial frog.

Acoustic restoration: Using soundscapes to benchmark and fast-track recovery of ecological communities

We introduce a new approach—acoustic restoration—focusing on the applied utility of soundscapes for restoration, recognising the rich ecological and social values they encapsulate. Broadcasting soundscapes in disturbed areas can accelerate recolonisation of animals and the microbes and propagules they carry; long duration recordings are also ideal sources of data for benchmarking restoration initiatives and evocative engagement tools.