When parents play favorites: brood demand shapes parental preference for offspring UV color.

Parents might initially produce more offspring than they might be able to raise. However, when offspring demand exceeds their parents´ rearing capacity, parents might shift care towards the offspring which yield greater fitness returns to achieve their optimal brood size via brood reduction. Such favoritism could rely on offspring signaling traits if these inform parents about offspring quality and hence about the pay-offs of their investment.