Spring Bird Migration: Time To Fly Back HomeMar 31st, 2017 | Category: Coastal Corner, MDC News
By Lisa D. Mickey
When you live in a Florida coastal community, bird migration is a noticeable event that happens twice a year. Migration is when birds move between their wintering and nesting areas.
This seasonal transit brings a variety of ducks, white pelicans and a host of other birds to Florida each fall. Florida marshes and shorelines provide an excellent place for our northern avian neighbors to spend several months eating, socializing and preparing for a busy nesting season.
In the spring, those flocks of Northern Robins we noticed in our yards during the winter months, fly home. Common Loons, visiting Florida waters each winter, tend to return to their northern homes in May. It is there that they develop their amazing seasonal checkerboard feather patterns and begin to call for mates.
Some birds, such as the red knot, have been known to fly more than 325,000 miles in a lifetime between wintering grounds in Tierra del Fuego, Argentina – the southern tip of South America — and their nesting grounds in the Arctic tundra north of Hudson Bay in Canada. These robin-size birds may be seen on our shores during the winter months resting and refueling during a 9,000-mile journey north.
Amazingly, red knots time their migration north to coincide with the spring season in which horseshoe crabs lay their eggs at Delaware Bay. The red knots consume massive quantities of food prior to leaving South America, so when they reach Delaware Bay in late May, they are ravenous. A single red knot can eat up to 8,000 horseshoe crab eggs a day, rebuilding its fuel store and preparing to continue its final 2,000-mile trip to the Canadian Arctic.
Seasonal migration for birds is fairly predictable and occurs twice each year. Birds may migrate because their food source is less abundant in certain colder climates during the winter months or weather conditions are too harsh for them to remain. According to The Sibley Guide To Bird Life and Behavior, “of more than 650 bird species that nest in North America, 75 percent engage in some form of migratory behavior.”
Heavy bird migration takes place each spring in April through May on the Gulf Coast, with birds migrating from the tropics into Texas and Tampa Bay. In one of the world’s most active areas of migration, avian migrants spread out throughout coastal areas, forests and plains. Cornell Lab of Ornithology estimates that up to 600 birds per cubic kilometer participate in trans-Gulf migration from the Yucatan and beyond.
But migration can be a dangerous time for birds. Not only can long trips leave them exhausted and famished, but they may also encounter storms, predators, windows of tall buildings or confusion by urban sky glow (light). Wisely, these high fliers take advantage of southerly winds in the spring and northerly winds in the fall as they transition between regions.
Climate change also may impact the timing of bird migration. In a recent Cornell Lab of Ornithology webcast, scientists discussed the possibility of a mismatch with the availability of food and the arrival of birds at seasonal destinations.
So while certain species of birds come and go in our coastal community, rest assured you will see them again when the wind changes direction, the temperatures in these birds’ nesting areas become unfavorable and “snow-bird season” brings avian guests back to town.
Just when we get used to seeing them, it’s time to go. And just when the blaze of a Florida summer has lifted and temperatures begin to fall, our feathered friends return to start the process all over again.