Bird Migration and Danger Recognition

Although maternal imprinting in mammal and bird species represents the
best-documented studies of imprinting behavior, imprinting may be involved
in other types of learned behavior. In migratory bird species, ethologists
have attempted to explain how bird populations navigate from their
summer nesting sites to their wintering sites and back every year without error.
Different species manage to navigate in different fashions. The indigo
bunting, however, navigates via the patterns of stars in the sky at night. Indigo
bunting chicks imprint upon the celestial star patterns for their summer nesting site during a specific critical period, a fact that was determined
by the rearrangement of planetarium stars for chicks by research scientists.
Further research studies on birds also implicate imprinting in danger recognition
and identification of one’s species-specific call or song. Young
birds of many species identify predatory birds (for example, hawks, falcons,
and owls) by the outline of the predator’s body during flight or attack and by
special markings on the predator’s body. Experiments also have demonstrated
that unhatched birds can hear their mother’s call or song; birds may
imprint on their own species’ call or song before they hatch. These studies
reiterate the fact that imprinting is associated with a critical period during
early development in which survival-related behaviors must become firmly
established. 426