Reason behind public vs. private signaling by a tropical rainforest bird identified

Washington, Feb 14 : A team of French and Brazilian researchers have found the reason behind the adaptation of the song of Brazilian white-browed warbler to the acoustic properties of the rainforest environment.

It is a great challenge to understand the evolution of acoustic communication systems in animals and how this evolution is affected by environmental pressures

The study, led by Nicolas Mathevon and Thierry Aubin, has shown that the song of the white-browed warbler, a species living in the Brazilian Atlantic rainforest is specifically well-suited to the acoustic properties of the environment, with its dense vegetation. The song can also vary in its acoustic properties depending on whether the message is "public" or "private."

The information regarding their species identity is available to remote individuals as territorial males signal this information using a song acoustic feature resistant to propagation. On the other hand, information concerning their individual identity is supported by song features susceptible to propagation, and thus restricted to neighbours.

In addition, this public versus private signalling, males can find the singers by using propagation-induced song modifications.

Therefore, the design of this communication seems to be well coordinated to the acoustic constraints of the rainforest and to the ecological requirements of the species.

It is highlighted by these results that the efficiency of a sound communication system results from a coding/decoding process particularly well tuned to the acoustic properties of the environment.

This allows the establishment of efficient local communication networks in the particular habitat of a tropical forest.The tropical rainforest ecosystem provides a unique opportunity to experimentally test theoretical models of acoustic communication.

This emphasizes the critical importance of tropical areas for dealing with the key biological questions and reinforces the urgency for protecting such major biodiversity hotspots as those of the Brazilian Atlantic forest.

This study is published in the online, open-access journal PLoS ONE.

ANI