exact details of the Arctic tern's migraion, as with most
bird migrations, are unknown. The
route is not necessarily direct, and the birds make stops
along the way.
Naturalists catch birds, place identification
bands on their legs, then release them. If
these birds are caught again, the bands help provide a
record of where the birds came from.
An Arctic tern banded in the Arctic Ocean was captured
again three months later11,000
of the Arctic tern report that they can be found for three
to four months in the Arctic region, and for
three to four months in the Antarctic region.
The blackpole warbler cannot swin,
yet it migrates over the open ocean from New England to
South America, a nonstop trip
of over 4000 miles.
Birds have been seen at elevations
of 30,000 feethigher
than Mount Everest. One
bird crashed into an airliner
at 37,000 feet.
Carrier pigeons have been clocked
at speeds of 35 mph.