Question

Southern yellow-billed hornbills live in the Kalahari Desert, which has low rainfall and high summertime temperatures. Yellow-billed hornbills live in breeding pairs or small family groups. When they begin their courtship, the male feeds the female for up to a month by bringing her small bits of food. Females are attracted to males with richly pigmented bills and less likely to choose a male with dull bills. However, males with richer pigmentation have trouble regulating their body temperature in warmer weather and often don’t survive to adulthood. On the other hand, females become more insistent on brighter pigmentation in hotter climates. As the effects of climate change increase, what pattern of natural selection would we expect with respect to the amount of pigment in males?

Answer 1

y