August 30, 2005
Wintering Grounds
Nest Update: Lightning has been the main osprey at the nest the last few days, although we've seen Thunder popping in and out, and she was there this afternoon. We haven't had a clear sign of the parents recently. I won't make any declarations about the parents being gone, because when I do they reappear! But it looks like the family might be thinning out.
On this day last year, during our 2004 cam season, one chick was seen at the nest, and two days later the eagles took over, as both osprey chicks had left for migration. But as we've mentioned before, our 2005 family started a bit late, so the chicks are still with us.
The Hawk Mountain website in Pennsylvania is reporting that 32 ospreys have already been spotted migrating past their mountain ridge since August 9, so it's clear that ospreys in the north are beginning their move to the southern wintering grounds. As the migration season officially starts, we can't help but wonder where our cam ospreys will eventually go once they decide to leave.
Ospreys are just as loyal to their wintering grounds as they are to their breeding grounds, so it's highly likely that the mother and father ospreys will head to the same places where they spent their previous winters. As for the chicks, they'll be picking out a winter home for the first time.
Technology, such as radio transmitters and satellites, have enabled us to learn a great deal about osprey migration. By putting a radio transmitter on an osprey, ornithologists can tell where the ospreys are stopping along their migration route and where they ultimately settle in for the winter.
Below is a hypothetical itinerary for our ospreys based on information taken from ospreys in the Martha's Vineyard area of Massachusetts that were tracked with a satellite during migration. In this scenario, the bird settles in the Orinoco River Delta of Venezuela, which is a popular area for ospreys; but keep in mind that mid-Atlantic ospreys could settle anywhere in Central or South America. Click on the map to follow the route:
* Leave Blackwater Refuge in Maryland in late August or early September
* Fly down the Delmarva Peninsula, across the Delaware Bay, and stop at Albemarle Sound, near Hertford, North Carolina
* Fly to Cape Fear, North Carolina and stop to rest and feed
* Leave the coast at Cape Fear, North Carolina and move out over the Atlantic Ocean
* Fly back over land near Osceola, Florida and the St. Johns River (a popular river for ospreys)
* Head down toward Miami, Florida and prepare to cross the Gulf of Mexico towards Cuba (Cuba is one of the major migration corridors for ospreys -- most breeding ospreys from eastern North America will make a stop in Cuba)
* Fly 120 mi. over the Gulf of Mexico to Cuba in less than a day
* Move slowly through Cuba, resting and feeding, and cross over to Hispaniola, northeast of Port-au-Prince (a popular spot for migrating ospreys arriving from Cuba)
* Fly almost 400 miles across the Caribbean Sea into South America and rest on the Guajira Peninsula in northern Venezuela
* Move gradually southeast across Venezuela -- resting and feeding -- and settle for the winter near the fish-laden Orinoco River Delta, which drains many of the rainforests of Venezuela
The ultimate destination will vary according to each osprey -- some will head west to Central America, some will stop as soon as they hit the South American mainland, and some will go farther south, possibly all the way into Bolivia.
Including side trips and time spent for feeding and resting, ospreys from the Chesapeake Bay area could fly 2000-4000+ miles during their individual journeys and take around 15-50 days to reach their final destinations.
One noteworthy thing about ospreys is that they are very powerful flyers -- even more so than other raptors such as eagles. The ospreys' strong flying abilities mean that ospreys are not reliant on thermals and updrafts for migration, so they are able to spend long periods of time flying over areas like the Gulf of Mexico, the Caribbean Sea, or the Sahara desert (for European ospreys), which is something other raptors can't do.
Besides increasing our admiration for the osprey's flying abilities, this itinerary also highlights something else important -- the need for bird conservation efforts in foreign countries.
When the ospreys are here in North America, we think of them as "our" birds and assume that they're relatively safe. But ospreys -- like most migrating birds -- spend much of their time in countries that do not have the political support or money for protecting migratory birds and their habitat. These are areas where habitat is being drained or overfished, where forests are being felled, where water pollution laws are weak, and where many raptors are shot because they are seen as a threat to livestock.
Over the decades, environmentalists have worked hard to use tools such as the Endangered Species Act, the Migratory Bird Treaty Act, neotropical research projects, environmental education, and events like International Migratory Bird Day to create the international support needed to ensure that all birds can move safely between their northern breeding grounds and their southern wintering grounds. We thank these groups and their volunteers for trying to provide a safe global home for so many intercontinental bird species, such as the osprey.
If you'd like to learn more about the lives of migratory birds, visit the interesting Migratory Bird section of the National Wildlife Federation website.
Until next time,
Lisa - webmaster