Parent–environmental interactions shape acoustic signatures in tree swallows

Submitted by avianbiology on 23 January 2014.

Acoustic signatures are common components of avian vocalizations and are important for the recognition of individuals and groups. In this study the authors investigate whether acoustic brood signatures are attributed to the genetic/maternal origins or to their rearing environment.
They show that calls does not vary based on the genetic/maternal origin, but on their rearing environment. Interestingly did control nestlings show the strongest brood signatures, suggesting that acoustic signatures develop through an interaction between rearing environment and genetic/maternal effects.

Below you can read what the authors say about their study.

Our study aimed at identifying what makes the calls of nestlings of a tree swallow family sound similar. This is important because call similarity between siblings is thought to help parents to find their young among other conspecific young, once the nestlings fledged. Nestling calls from control families showed clear acoustic similarities and could easily be discriminated from nestlings from other families.

To identify if nestlings sound similar because they share an inherited “voice” or because they acquired a common “dialect” or if it is a combination of both, we used a cross-fostering experiment in which we swapped nestlings of only a few days of age between nests. When nestlings were close to fledging, we recorded them sitting at their nest box entrance. Our results showed that cross-fostered nestlings growing up together did not show clear similarities, neither did true siblings growing up in separate nests. This finding suggests that not one factor alone, neither inherited nor acquired, shapes a nestlings call, but a combination of both makes true siblings, that are growing up together in their parents nest, sound similar and gives them their call signature.


Photos by: Alan Dorey, Elisabeth Fairhurst & Hendrik Reers

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