A nest’s primary function is to provide protection for developing offspring. However, nests can also be very conspicuous, decorated, or used as part of elaborate displays (usually conducted by males). This is surprising since inconspicuous nests should be favoured by natural selection in order to avoid nest predation. It is therefore likely that other factors influence nest evolution. This project is part of an ANR-funded project (“Extended Phenotype”) awarded to Claire Doutrelant (Pi) & Rita Covas (Co-Pi), and PhD student Erwan Harscouet is researching the factors associated with the diversity of nests’ characteristics and associated signals. Erwan’s work is co-supervised by Julien Renoult and done in collaboration with Dieter Oschadleus, Fanny Rybak and Staffan Anderson. We ultimately hope to understand why some birds’ nests are more elaborate or conspicuous than expected.

To answer this question, we study the Ploceidae family and we are trying to determine:

1) Which factors contribute to the evolution and diversification of weaver nests?

2) How diverse are the nests when species live in sympatry?

3) What are the links between nests and acoustic and visual signalling?