Thursday, February 10, 2011

Trash Birds

This post gives a new twist to the definition of "trash birds."  The term usually refers to birds, like starlings or House Sparrows, that are so ubiquitous that they are hardly worth noting.  In this case, however, the reference is to birds on trash bins.  Above is a male Satin Bowerbird in southeastern Australia.  This bowerbird builds a stick structure (the bower) and collects all things blue to entice his mate.  "Come see my blue stuff," he seems to proclaim as he dances in front of his bower.  Satin Bowerbirds collect all sorts of trash--feathers, buttons, clothespins, pieces of plastic, ballpoint pens, cellophane wrappers--all sorts of trash. Rival males even steal from rival's bowers.  If the female, who has visited the bowers when the male is absent, is interested, she enters the bower and copulation ensues. 
Our 17-month Ecuadorian research was interrupted by the opportunity for a two-week tour of the Galapagos Islands. Here Darwin began to hatch his theory of evolution and speciation.  He became impressed that the birds of the islands were not as diverse as those on the mainland.  Instead they appeared to have descended for a common colonizing ancestor.  Immediately upon landing on the islands, we encountered our first Darwin's Finches.  The birds, like the Medium-billed Ground Finch in the foreground and the Small-billed Ground Finch further back, although similar in appearance, had evolved slight differences..  Had Darwin never lived, I doubt that I would have been sufficiently brilliant to discover evolutionary biology.

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