The battles over immigration in the other Washington got me thinking about the annual migration of song birds.  While human immigration is a complex mixture of economics, sociology, and politics, the avian migration is just as complex but involves evolution, physiology, ecology, and navigation.  The birds travel from southern Mexico, the Caribbean, and Central and South America, a biogeographical region known as the neotropics.  Humans give them the clinical sounding name of neotropical migrants but I would call them amazing migrants.  Many migrants visit us in the spring and summer so let’s look at some.

Swallows are one of the first amazing migrants that come to mind.  Their arrival signals spring and their graceful flight is inspiring.  The barn swallow (Hirundo rustica) winters in the eastern lowlands of Mexico to Argentina and can cover 600 miles a day while migrating.  Interestingly, they migrate at a height of about 100 feet eating on the wing.

Swainson’s thrush (Cathartus ustulatus) is a favorite amazing migrant that is challenging to observe but thankfully not to hear.  Birders eagerly wait for the day when they once again hear the rising flute of their voice.  Our Swainson’s thrush, those of the Pacific coast spend the winter from southern Mexico to Costa Rica.  But the story is more complicated.  The Swainson’s thrush that summer in the interior first migrate east to Florida then south, to winter from Panama to Bolivia.

The black-headed grosbeak (Pheucticus melanocephalus) will winter in Mexico and migrate here in the spring.  A bird wary of humans, it sings like a drunken robin and males are a dazzling orange, black and white.  This species prefers deciduous forests and is actually increasing in numbers here in the Puget Sound region.  This is because the lowland coniferous forest has been cut and the preferred broadleaf trees have grown in some of the semi-rural and treed suburban areas.  However, as concrete suburbia spreads, you can expect these amazing migrants to decline.

 

            Like the Swainson’s thrush, osprey (Pandion haliaetus) of the east and west winter in different regions.  The Caribbean and South America is where osprey of the east prefer to winter.  Our osprey will travel to Mexico and Central America.  If you would like to see a migration in progress, check out this web site - http://www.dnr.state.oh.us/wildlife/Resources/osprey/migration.htm.  The Ohio Department of Natural Resources has satellite tagged a male and female and you can see their progress as they migrate north.  Here in our backyard, we have one of the largest breeding colonies on the west coast.  The osprey of Port Gardner need our attention.  They nest on bundles of pilings called dolphins, but these may be removed in the near future.  The Pilchuck Audubon Society is concerned that the colony will die out if this happens and would like to see nest platforms installed as the dolphins are removed. 

It is thought that the primary reason birds migrate is to take advantage of a better climate.  Why not?  Humans do, we call them “snow birds.”  This spring, take a moment to reflect on where that black-headed grosbeak on your feeder has been and the journey the Swainson’s thrush has made to sing in the woods near you.  You can also celebrate International Migratory Bird Day (IMMBD).  There are many activities in which to participate and you can have your own celebration at your feeder.  See http://www.fws.gov/birds/imbd/ for more information about IMMBD.


(Article written & provided by J. Baker)

 

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