Plumage color provides information about the immune system
At least in the case of collared flycatchers (Ficedula albicollis), the plumage coloration provides potential mates with information about the development and effectiveness of the male immune system.
The females prefer collared flycatchers with the largest possible white spots on the front forehead, as this is probably the main indication of the state of he alth and the strength of the immune system of the animals. In the opinion of Måns Andersson and his colleagues from Uppsala University, the males thus indicate that they are also better equipped to deal with future, mutated pathogens than their competitors and that they can pass on this advantageous disposition to their offspring.
In their study, the scientists discovered that collared flycatchers with the appropriate coloration after vaccination against Newcastle disease – a widespread bird disease – produce significantly more antibodies than conspecifics with less pronounced coloration. This confirmed a previous study for the biologists, which also demonstrated a lower level of contamination with blood parasites in the brightly colored males of collared flycatchers.
Until now, the formation of the plumage was primarily considered an indicator of the current state of he alth of the animals and their genetic makeup, but not as a general indication of the performance of the immune system.
