Acoustic Differentiation Between Courtship and Advertisement Calls in the Poison Frog Oophaga sylvatica (Dendrobatidae, Anura)

Anuran vocalizations are crucial for essential behaviors such as reproduction and territoriality. While advertisement calls are extensively documented, subtle courtship calls remain poorly studied. This is worrisome as these calls play an important role in mate selection and reproductive success. Oophaga sylvatica is an ideal study object due to its abundance, disturbance adaptation, and complex reproduction behavior, whose courtship call has never been described. This study provides the first characterization of the O. sylvatica courtship call from northwestern Ecuador and compares it directly to the advertisement call. Utilizing modern bioacoustic analysis to convert sound into quantifiable data, we determined that the courtship call consists of uniform, non-modulated pulsed notes (mean duration: 0.083 s; dominant frequency: 3239 Hz). The courtship call differs from the advertisement call by having longer notes and narrower frequency, with no change in amplitude. This suggests an adaptation for private, close-range communication, potentially allowing a male to signal his fitness to a female while minimizing the risk of alerting competitors or predators. These findings provide new insights into the acoustic communication in this species, helping bridge knowledge gaps in its reproductive behavior and discussing the role these calls play in courtship, mate selection, and reproductive success.