Editor’s Note: Brooklin author/photographer Richard J. Leighton creates the popular “In the Right Place” posts online about life and nature in Maine. He will share a post the second Thursday of each month in The Ellsworth American.
Have you noticed that many of those huge nests on man-made platforms and in the tops of large trees are abandoned now? Just a little while ago, they were the homes of frenetic osprey parents trying to raise families of high-performance youngsters.
Ospreys breed in Maine during the spring and summer, usually raising a family of three big fledglings. However, September is the peak month for our “fish hawks” to go their separate ways and migrate south alone for winter vacations. They make a perilous journey to their second homes many miles away. Thousands of them are on their way as you read this.
But, it wasn’t always this way. Life has improved for ospreys here during the 21st century. As with bald eagles, the numbers of ospreys decreased to dangerous levels in the 1950s and ’60s due in large part to pesticides such as DDT in fish, which are ospreys’ almost exclusive food. Since the banning of those pesticides, osprey and bald eagle numbers have resurged, creating an irony in Maine, where bald eagles are now driving ospreys from their nesting areas in some places.
Virtually all of Maine’s healthy ospreys migrate south, according to reports. The birds’ existence depends on their ability to plunge-dive for fish that are swimming near the surface of water. Freezing temperatures make diving into iced-up lakes and rivers impossible or dangerous, while winter diving into the sea becomes unproductive when many fish swim at lower, warmer depths. However, as temperatures increase due to the climate warming, the odds increase for ospreys to become year-round Maine residents.
But now, our ospreys are seasonal residents and continue to undertake heroic spring and fall migrations. Researchers recently have been able to study those flights more closely, thanks to compact tracking devices placed on the backs of sample birds and organized web-based census efforts. The result has been a trove of amazing and troubling discoveries about the brave birds.
As for the fall migration, we now know that the majority of our ospreys set out to spend the winter along the coasts and rivers of Central and South America, but many do not survive the trip. Among other reported catastrophes, the migrators get electrocuted by power lines, hit by cars and trucks, shot by chicken and fish farmers and blown off course by hurricanes and other high-wind events.
Unlike many raptors, ospreys don’t rely on updrafts and thermal air currents to fly long distances. They are extraordinarily powerful fliers that usually fly early and late in the day when thermals are not much of a factor. And, ospreys are the only migrating hawks that dare to take shortcuts over deserts and vast expanses of open sea.
Also, unlike other hawks, they don’t “fatten-up” energy reserves for migration; they eat when they can during the journey and some even have been seen “packing lunches” — carrying fish with them as they fly over inhospitable places.
Our northeastern ospreys usually fly south alone or in small groups, funneling between the Appalachian Mountains and the coast until they run out of rivers and land. Without hesitation, they fly over the Caribbean Sea to rest a bit in Cuba or other Caribbean islands. From there, they tack west and southwest over to Central and South America.