Research discovers darker feathers mean healthier pigeons
A study of pigeons in the centre of Pairs has discovered birds with darker feathers are healthier, have stronger immune systems and are more attractive to the opposite sex than their lighter coloured counterparts.
A team from the National Centre for Scientific Research in Paris began by examining why birds of the same species may be coloured differently.
Studying 195 urban pigeons in Paris, the team looked at the colour of their feathers and assessed their health. They found that pigeons with darker coloured feathers had lower concentrations of a blood parasite called haemosporidian. Their immune systems were stronger and reacted quicker to fight infection compared to pigeons with lighter coloured feathers.
Lisa Jacquin, who led the team of researchers, uncovered that the reason could lie in an evolutionary development. There are currently two theories for the different coloured plumage. One suggests it is derived from environment, 'exposure' hypothesis. The other uses a basis of genetics, suggesting the birds have evolved to produce different levels of melatonin.
The new research has discovered it is the genetic development that has led to the different colours of feathers and postulates this has happened to help protect their immune systems. Research in England and Russia has previously discovered there are more dark feathered pigeons in urban areas, where there are more parasites and a greater risk of disease and infection.
Lisa Jacquin explained to the BBC, ''The finding that immune responsiveness and parasite intensity correlates with colouration suggests that melanin-based colouration could play a role in sexual selection''.
The research has been published in the Journal of Avian Biology.