Fejlődési dinamika, egyedi minőség és tollazati jelzések = Developmental dynamics, individual quality and plumage signals

1) A récefélék fehér szárnyfoltjaival evolúciósan kapcsolódnak egyes viselkedési és életmenet-karakterek. Az örvös légykapók két fehér tollazati foltjának eltérő a metabolikus indikátor szerepe. A fehér homlokfolt öröklődik, a rá mutatott preferencia viszont nem. A tollazat fényvisszaverése integrált, párbaállást befolyásoló plasztikus jelzésrendszert képez. 2) A tojásban található többféle androgén hormon egymástól eltérő hatást fejt ki a fiókák fejlődésére és túlélésére a japánfürjnél és az örvös légykapónál. Az utóbbi fajnál kontextusfüggő túlélési szelekció hat a fiókanövekedésre, a növekedési plaszticitás mértéke pedig összefügg a táplálék szezonalitásával. 3) A récefélék fehér szárnyfoltjai együtt evolváltak a hímek utódnevelési hozzájárulásával. Az örvös légykapó tojók fehér szárnyfoltjának mérete a tojás androgéneken keresztül összekapcsolódik a fiókák növekedésével. A növekedésre ható túlélési szelekció iránya függ az apa fehér szárnyfoltjának méretétől. | 1) Some behavioral and life-history traits are evolutionarily linked to the white wing patches of ducks. The two white plumage patches of collared flycatchers have different metabolic indicator roles. The white forehead patch is heritable, but the preference on it is not. Plumage reflectance constitutes an integrated, plastic signal system with a role in mate acquisition. 2) Different androgen hormones in the egg differ from each other in their effects on nestling development and survival in Japanese quails and collared flycatchers. In the latter species, survival selection on nestling growth is context-dependent, while the magnitude of growth plasticity depends on the seasonality of food supply. 3) The white wing patches of ducks have co-evolved with the parental contribution of males. The white wing patch size of female collared flycatchers is linked to nestling growth via egg androgens. The direction of survival selection on growth depends on the white wing patch size of the father

Depigmented wing patch size is a condition-dependent indicator of viability in male collared flycatchers

Honesty of sexual advertisement is thought to be the result of signalling costs. Because production costs of depigmented plumage patches are probably very low, their role as honest signals of individual quality has been questioned. Costs of bearing these traits, however, should also be taken into account. Studies on proximate determination and possible information content of white badges are very rare. We investigated repeatability, sensu lato heritability, and condition- and age-dependence of white wing patch size, a male display trait in a population of collared flycatchers (Ficedula albicollis), based on 4 years of data. By comparing relationships between age and wing patch size (1) within individuals among years versus (2) among individuals within years, we could address the viability indicator value of the trait. Wing patch size approximately doubled at the transition from subadult to adult plumage, and its change was significantly related to body condition the previous season. Repeatability and heritability values suggest that the trait is informative already in subadult plumage, and that genetic and early environmental effects are important in its determination, the latter only during the first year of life. Thus, wing patch size can act as a condition-dependent signal of genetic quality. Indeed, discrepancy between results from the horizontal and vertical age-dependence approaches shows that the trait was positively related to expected lifespan. After examining several alternative explanations, we conclude that wing patch size indicates genetically based viability. This is the first study to demonstrate a good genes viability benefit conferred by a depigmented plumage patch