Bill colour preference does not play a major role in the sub-species barrier between red- and yellow-billed long-tailed finches

In the paper published in Ecology & Evolution, we report on experiments in which we assessed mate choice by both females and males for members of the opposite sex with bills colours that were either the same as their own, or those of the alternate sub-species. These findings differ from those found in some other hybridising species, where colour signals make an important contribution to pre-copulatory species barriers. The findings help us to understand the evolutionary processes that maintain the divergence between the two forms in the wild across northern Australia. The full paper, led by Callum McDiarmid, and part of his PhD on speciation in this species, can be found here.

The Distribution of the two sub-species of the long-tailed finches across northern Australia with the shading indicating bill colour, with a narrow hybrid zone between the two forms.

Despite the lack of clear assortative mating on the basis of bill colour, the displacement of the contact zone illustrated above in orange, with the area in which most of the genomic divergence occurs (shown with a dashed line), suggests the introgression of the bill colour genes from the west towards the east. This finding can be partly explained by the potential dominance of at least some of the genes for bill colour. In our study we report the findings from experimental crosses between the subspecies in captivity where the colour of the bill in female F1 hybrids is dependent on their father, supporting this idea.

Sperm in finches: not too many, not too few

Today saw the publication of the first paper from Lori’s thesis (yay). The paper, published in the Auk, focuses attention on the variation in the number of sperm trapped in the perivitelline layer of the membrane of the egg. The paper is supported  by a Blog post written by Lori.


Peri’s second paper!

Peri’s second paper was published today in Molecular Ecology. It was a follow up to her first paper which attracted useful discussion by Anders Forsman (Lund, Sweden). The new paper clarifies our thoughts on why polymorphic species might be vulnerable because of the negative interactions between different morphs. Conceptually it builds from our work on the Gouldian finch and long-tailed finch.

The paper can be found here: