“To everything there is a season, A time for every purpose under heaven:” (Ecclesiastes 3:1 NKJV)
Here are some interesting statements from an article on All About Birds. The research that Cornell Lab of Ornithology scientists are discovering with weather radar data is assisting the ornithologist. They are learning more about the 4 Billion birds that migrate during this time of the year.
“An average of 4 billion birds passed from Canada across the northern border of the U.S. in autumn, with 2.6 billion birds returning across the Canada–U.S. border in spring. Activity across the southern border was on an even grander scale: an average of 4.7 billion birds left the U.S. for Mexico and other points south each autumn, with 3.5 billion birds heading north across the U.S. southern border each spring.”
That is quite a few birds heading south, with fewer returning in the spring. It appears the birds that go further south have a better survival rate than the ones that winter here in the United States.
” For birds crossing the U.S. northern border—which includes many short-distance migrants such as sparrows, Snow Buntings, and Dark-eyed Juncos that fly from Canada to spend winter in the Lower 48 states—the average rate of return was 64 percent. But for birds crossing the U.S. southern border—which includes more of the long-distance migrants such as warblers, tanagers, and orioles that travel to Central and South America, three to four times farther than the short-distance migrants—the average rate of return was 76 percent.”
My first thoughts were why are so many not surviving here in North America. Yet, those traveling further south, seem to fare better. I knew from previous articles I’ve read that many birds die from impact with tall buildings and glass windows. Here is what they had to say:
One explanation for the higher mortality among birds that overwinter in the U.S. may be a higher number of hazards. “All birds need to stay safe from predators, find enough food, and not get hit by a car,” says Ken Rosenberg, research coauthor and conservation scientist at the Cornell Lab. “Birds wintering in the U.S. may have more habitat disturbances and more buildings to crash into, and they might not be adapted for that.”
They also discuss in this article the differences in different breeding strategy between short distant and long distant migrants.
“And He changes the times and the seasons;” (Daniel 2:21 NKJV)
Here in Florida, I have begun seeing more of the migrants that spend time near here. The Boat-tailed Grackles are invading my feeders already. I have also spotted more Bald Eagles, and the Heron, Egrets, and Sandhill Cranes seem to be more populous. Yeah, for the Winter Visitors!!
4 Billion Birds Will Fly Through American Airspace This Fall by Carley Eschiman, All About Birds, Sept 17,2018