The resulting difference in fitness-limiting factors necessitates a separate consideration of female and male reproductive strategies. Although the focus here is on male strategies, male ...

As you begin to see nests full of baby chicks and fledgling birds hopping around in your backyard, you may wonder: how do ...

This asymmetry leads to Bateman's principle, whereby female reproduction is primarily limited by their access to resources to nourish and produce these large gametes, whereas male reproduction is ...

Female and juvenile cowbirds are mostly brown with cream-colored wing bars. All species of cowbirds are obligate brood parasites. “That is a fancy way of saying that they never build nests and ...

Adult male: the glossy black body, with a greenish iridescence, contrasts with a brown head. The eyes are dark; the bill and legs are black. Adult female: dull brownish throughout, with darker ...