When Charles Darwin first came upon the Galapagos Islands, he wasn't as impressed with the diversity of bird life he found there as is widely believed. It was later, at home, that his observations of the beaks of finches led him toward his revolutionary theory of evolution. Still, the finches of the Galapagos have an unparalleled place in the minds of conservationists.
Now, on the island of Santiago, the fourth largest in the Galapagos Archipelago, a bird resurgence is poised to begin. And it's all because of goats.
More accurately, the decline in local finches resulted from the feral goats released on the island in the 1920s. In their first 70 years, they chewed through every bit of brush on the 226-square-mile island (that's about the size of Manhattan and Galveston islands combined). In their wake: grass ... and fewer birds.
The story of the Galapagos is that similar species developed unique adaptations to living on different islands, each with different habitats. The woodpecker finch, on Santiago Island, learned to use a twig, stick, or cactus spine as a tool to dislodge grubs and insects from trees.
The island was declared goat-free in February, after the largest "invasive mammal eradication" effort ever completed, according to the American Bird Conservancy. Now, the birds are free to return, following the island's shrubs and trees.
Meanwhile, in Texas ... the 600-mile long and growing border fence being constructed in an attempt to keep illegal Mexican migrants south of the border is threatening birds and other wildlife closer to home, according to the Cornell Lab of Ornithology. The fence is creating island-like environments where populations are cut off from one another; unlike in the Galapagos, this is more likely to lead to extinction than evolution, given that the Galapagos wildlife had millions of years to adapt. Because so much of the surrounding landscape has already been developed, this border area is some of the most important wildlife habitat around.
"Birders come to the Rio Grande Valley for glimpses of tropical species that make their only appearance in the U.S. right here," the lab reports. "Species including the improbable yellow-green-and-blue Green Jay and fiery Altamira Oriole. Two unusual sizes of kingfisher live here, the burly Ringed and the almost dainty Green. Flashy Great Kiskadees, intensely mauve Red-billed Pigeons, and so-small-you-might-miss-them Least Grebes and Ferruginous Pygmy-Owls are just some of the species you would otherwise have to leave the country to see. A few dont occur any farther than a dozen miles north of the border.
"Two small wildcat species the ocelot and the jaguarundi are also rare inhabitants of the South Texas border. In states farther west, desert bighorn sheep and Sonoran pronghorn live a tenuous existence on limited stretches of habitat straddling the border. In each case, the fences twin side-effects, habitat destruction and disconnection, reduce the likelihood that these species will persist in the small patches of habitat that remain north of the border."
If you want to help preserve the birds in your backyard, you can do a lot to create good bird habitat on your property. The National Audubon Society and The Daily Green teamed up recently to provide 25 bird conservation tips anyone can do, including 15 tips for making your garden friendly to birds and other wildlife. Try them.
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