By the time you read this, the annual spring bird migration will be well underway. Like water gathering behind a dam, each spring the dam (winter) breaks, and a flood of migratory birds wash over the frozen northland. Each bird in a race to return to the best breeding grounds.
The avian (bird) world is much like the mammalian (animal) world. There are two main objectives in life. Find food and reproduce. Migration is the answer (for many species) to both of these objectives. Finding food is a constant in a bird’s life. Every day-all day-birds are in a constant search for food. When the food supply runs low or worst yet runs out, such as insects in winter, the birds are forced to migrate.
Many species of birds are considered neotropical migrants. All of the swallows, including the Purple Martin are neotropical migrants. As I already mentioned, most species of warblers are, but some such as the Yellow-rumped Warbler are not. A species of hawk-the Broad-winged Hawk makes an annual trip to South America each year.
One might think that our beloved American Robin is a true neotropical migrant. Even its scientific name Turdus migratoris indicates it’s a migratory species. However, it moves only far enough south to find food and never sees the tropical forests of Central or South America. It is still considered a migratory bird but it’s not a neotropicals migrants.
Even the jewel of the prairie, the Eastern Bluebird only goes far enough south to get by for another winter. In fact, they don’t leave the northland until mid November and often return in the first couple weeks of March. The denizen of the grassland, the Horned Lark (North Americas only lark species) follows a similar pattern as the bluebird. It migrates back in mid February. None of these birds are neotropical migrants.
Ducks such as the Wood Duck and Hooded Mergansers are like the robin and bluebirds. Each spring they migrate north just as the small ponds and lakes thaw. Sometimes they fly north searching for open water, and finding none will return back south only to try again in a couple days. My Wood Ducks usually show up the day after the ice clears from the pond outside my window. Most Bald Eagles are the same way. It’s not uncommon to see them standing around on the icy surface of a frozen lake in spring.
Early migration usually results in securing the best habitat with plenty of food. Females seek out the males with the best territories thus the best food supply. A plentiful food supply means the baby birds will grow up quick and strong. Just by having the best habitat a bird insures a good food source and a chance at reproducing.
You see, its all about food and reproduction. This spring get out to witness the flood of migrants because it won’t be long before they will be heading south again for another winter.
Until next time…