Patterns of stopover habitat use by migrating landbirds are striking when source
stopover habitats are highly isolated. Birds departing habitat fragments or
islands represent the most pronounced examples of this phenomenon. The animation
below depicts birds departing several islands in northern Lake Michigan. In some
cases bird echoes reveal the locations of islands where the map does not.
This series also shows the time course of migratory exodus. Although most birds
appear to depart shortly after twilight, bird echoes continue to stream off island
habitats and the Door Peninsula more than an hour into the nocturnal migration.
The animation clearly shows these birds moving directly south off the islands
and Upper Peninsula of Michigan. Birds departing the Door County peninsula in
Wisconsin however, appear to be moving southeast. This is perhaps in response
to different wind conditions associated with the storm visible to the
west-southwest.
Frames 3-5 show strong concentrations of birds along the northeastern
coast of the Lower Peninsula of Michigan, suggesting that at times, these areas (Leelanau
Peninsula, Charlevoix, Petoski) may be particularly important stopover habitats. In this
closeup of frame 4, these "hot spots" and 8 islands are distinctly visible in the echo
pattern of birds during takeoff.
The University of
Southern Mississippi. Last modified:
15 July, 2004 4:50 PM
. Questions for Webmaster
College of Science
and Technology
URL: http://www.usm.edu/biology/islands/index.html