During their lifetime, many female birds establish a pair bond with a single male with whom they build a nest and rear young. Many of those females, however, also copulate with other males outside the pair bond; the young they raise are fathered by more than one male. If we want to understand the role of genes and the environment in shaping this behavior, we want to understand its:

Many female birds establish a pair bond with a single male with whom they build a nest and rear young. Many of those females, however, also copulate with other males outside the pair bond; the young they raise are fathered by more than one male. If we want to understand how this behavior originated and how it may have changed over time, we want to understand its:

Stimulus recognition is carried out by _____, specialized sensory receptors or groups of sensory receptors.