Tuesday, March 27, 2007

Hummer Migration facts

From the migration page on hummingbirds.net:

Most Ruby-throated Hummingbirds winter between southern Mexico and northern Panama. Since hummingbirds lead solitary lives and neither live nor migrate in flocks, an individual bird may spend the winter anywhere in this range where the habitat is favorable, but probably returns to the same location each winter. Ruby-throats begin moving north as early as January, and by the end of February they are at the northern coast of Yucatan, gorging on insects and spiders to add a thick layer of fat in preparation for flying to the U.S. Some will skirt the Gulf of Mexico and follow the Texas coast north, while most apparently cross the Gulf, typically leaving at dusk for a nonstop flight of up to 500 miles, which takes 18-22 hours depending on the weather. Although hummingbirds may fly over water in company of mixed flocks of other bird species, they do not "hitchhike" on other birds. Some hummingbirds land on offshore oil rigs or fishing boats to rest. Individual birds may make landfall anywhere between southern Texas and central Florida. Before departing, each bird will have nearly doubled its weight, from about 3.25 grams to over 6 grams; when it reaches the U.S. Gulf coast, it may weigh only 2.5 grams. It's also possible that a few Ruby-throats island-hop across the Caribbean and enter the U.S. through the Florida Keys.

Males depart Yucatan first, followed about 10 days later by the first females. But the migration is spread over a three-month period, which prevents a catastrophic weather event from wiping out the entire species. This means that a few birds will arrive at any location very early (the dots on the migration map), but the bulk of the population will follow later, so you may not see your first hummingbird for several more weeks. Each individual has its own internal map and schedule, and "your" birds may arrive early, late, or anywhere within a two-month span.Once in North America, migration proceeds at an average rate of about 20 miles per day, generally following the earliest blooming of flowers hummingbirds prefer. The northward migration is complete by late May. Banding studies show that each bird tends to return every year to the same place it hatched, even visiting the same feeders.



Well, in that case: Welcome Home, little fellows!