Research into a distinctive bird has found a genetic quirk that gives rise to three types of male in the same species.
Scientists have identified a supergene in the birds’ DNA that is solely responsible for three different kinds of males found among ruffs.
Male ruffs can either have feathered collars - used in mating displays - or not, and either defend a territory or sneakily hang out on other males’ territories.
This gives rise to three types of the wading bird: collared, territorial independents, collared, non-territorial satellites, and non-collared, non-territorial faeders.
Edinburgh scientists used new technologies to produce the complete gene sequence of the ruff genome - a catalogue of all its DNA - and to identify which parts of the DNA were responsible for the differences in mating plumage and behaviour.
The team found that in the satellite and faeder birds some of the DNA of one of the birds’ chromosomes was inverted compared to the independents’, and that additional variation within this inverted DNA gave rise to the two types.
This inversion affects genes that influence plumage colour, and biological pathways that affect sex hormone production.
The team found that the three different types of ruff correspond to different hormone levels found during mating, which correlates with genetic findings.
The research, published in Nature Genetics, was carried out by Edinburgh Genomics in collaboration with scientists from Sheffield, Canada, US, Netherlands, Russia and Austria.
It was supported by the Biotechnology and Biological Sciences Research Council and the Natural Environment Research Council.