|Orange and black oriole on a sprig of ocotillo|
Each spring what few trees there are along the upper Texas coast change color. The color comes not from leaves turning red, gold, and yellow as in the autumn, but from birds. Literally thousands of warblers, orioles, tanagers, grosbeaks, buntings, vireos, and other species give the landscape a spectacular display of living color.
The birds coming to Texas in April and May are known as neotropicals, a term describing birds that migrate from their nesting habitat in the United States and Canada to tropical habitats in Mexico and Central and South America rather than stopping along the Gulf Coast for the winter. Included in this huge category are more than 250 species of small songbirds, and they're the ones that become temporary Texans.
In early March, the birds begin gathering on the Yucatan peninsula in Mexico, resting from flights that may have already brought them a thousand miles. For several weeks they feed heavily to store energy and build up fat reserves, since the most demanding part of their northward migration lies ahead more than 600 miles across the Gulf of Mexico.
This is what makes the trees and bushes of the upper Texas coast so important; it is the first landfall the birds have after hours of nonstop flying. Although many continue northward for another hundred miles or so before landing, thousands stop at this first opportunity.
The trip might be as short as 12 hours if the migrants can take advantage of strong southerly winds, but several times each spring the birds run into a huge thunderstorm or an unseasonably fierce north wind that makes the trip 24 to 30 hours. Many migrants perish in the Gulf, but those that do reach Texas drop out of the sky totally exhausted.
This is known as a fallout, and it is one of the most unforgettable spectacles in all of ornithology. One tree may have 15 or more different species of warblers, another will be filled with orange and black orioles, scarlet tanagers, and rose-breasted grosbeaks. Even ruby-throated hummingbirds will be present.
Bird migrations have fascinated humankind for hundreds of years, and the migrations of the neotropicals are even more remarkable because of the small size of the birds. They are forced to migrate because winter brings an end to their food supply. Between August and October these same birds, many of them in their immature plumage, gather along the Texas coast before making the southern Gulf crossing. It is their return in the spring, however, when they have their brightly colored adult plumage, that draws the most attention. For many observers, the arrival of the neotropicals signals the true beginning of spring and the start of another of nature's wondrous cycles.
Details mentioned in this article were accurate at the time of publication