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| Billions of songbirds migrate several thousand kilometers from
breeding to wintering grounds and are challenged with crossing
ecological barriers and facing displacement by winds along the
route. A satisfactory explanation of long-distance animal navigation
is still lacking, partly because of limitations on field-based
study. The navigational tasks faced by adults and juveniles differ
fundamentally, because only adults migrate toward wintering
grounds known from the previous year. Here, we show by radio
tracking from small aircraft that only adult, and not juvenile,
long-distance migrating white-crowned sparrows rapidly recognize
and correct for a continent-wide displacement of 3,700 km
from the west coast of North America to previously unvisited areas
on the east coast. These results show that the learned navigational
map used by adult long-distance migratory songbirds extends at
least on a continental scale. The juveniles with less experience rely
on their innate program to find their distant wintering areas and
continue to migrate in the innate direction without correcting for
displacement. | |
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