Do Diamond Firetails (Stagonopleura guttata) recognise the scent of their nest as other Estrildid finches do?

Olfactory nest recognition has been demonstrated in several avian species, including some gregarious Estrildid finches. In social species, which also form breeding colonies, olfactory nest recognition gives parents and fledglings the opportunity to identify the natal nest. However, in less social birds, such as Diamond Firetails, which rarely breed in colonies, the benefit from olfactory nest recognition is potentially less pronounced. Using a set-up that has successfully been used in odour discrimination tests in other Estrildid finches, we tested whether Diamond Firetail parents and fledglings recognise the scent of their own nest. We found no evidence of olfactory nest recognition, either in parents or in fledged juveniles. This might indicate that Diamond Firetails have limited olfactory abilities, or that they utilise their olfactory capacities in other contexts which may be related to a certain extent to their lifestyle which is less social than that of other closely related species. Our results reveal new insights into potential selective pressures underlying the interspecific differences in olfactory nest recognition among Estrildid finches, and how the species-specific ecology may have shaped sensory recognition.