Click here to: Subscribe to the email "New Maps Alert" list.
CONTENTS (click on the links to jump to that section.)
- Migration patterns for North American
2000 I began collaborating with Mark Martell, who was then working with The
Raptor Center at the University of Minnesota. At that point, Mark had already
put well over a hundred satellite transmitters on Ospreys all over the US and
followed their annual migrations from the breeding grounds to wintering areas in
Mexico and Central and South America. (Mark now works for the Minnesota Audubon
office as their Director of Bird Conservation.)
work elucidated several patterns
in Osprey migration across North America. The Pacific
Northwest birds all make a non-stop sprint migration over the western deserts
and winter in Mexico and Central America. None of these birds
went as far as
TRACKING ON MARTHA'S VINEYARD, RHODE ISLAND, SOUTH CAROLINA, NORTH
CAROLINA, DELAWARE, AND NEW
No new birds were tagged in 2002. KC returned from his wintering area in
Venezuela only to find a young male claiming his territory. He was late getting
back (he left his wintering grounds a week after the first Ospreys arrived on
the Vineyard), so I suspect he may have been an old bird. (Maps)
In 2004 the BBC contacted me and asked if I'd help with a series of documentaries they were planning entitled "Incredible Journeys." They wanted to start with Ospreys and offered to buy 4 transmitters if I would help them with their show. Never one to look a gift horse in the mouth, we put their transmitters on 4 Vineyard Ospreys and the transmitter recovered from KC on a fifth bird. On our first expedition to the Island we tagged an adult female (Elsie) at her nest in Edgartown and an adult male (Bluebeard) near the great clay cliffs of Aqunnah. We then ran out of luck and time and couldn't catch any more adults but still had 3 BBC transmitters to put on birds. So we came back in late July and put the transmitters of 3 young birds, Tasha, Bunga, and Jaws. Tasha and Jaws turned out to be the stars of the BBC's show. Bunga died near New London, CT. (We we were able to find the transmitter and use it in 2005.) Tasha made it to Hispaniola, where she went off the air. I suspect she wound up in a soup pot. Jaws made it to Colombia and settled down at an enormous lagoon, which was nothing short of Osprey heaven. Bluebeard, after an extended stay near the nest taking care of an apparently incompetent offspring, migrated deep into Columbia, almost at the Brazilian border. The documentary (Osprey Oddysey) aired in 2007 on the Animal Planet. (Maps)
In 2005, Bluebeard returned to his nest in the spring. We tagged a young bird (Homer) on Martha's Vineyard and a young bird (Conanicus) on Conanicut Island in Rhode Island. Conanicus migrated as far as Cuba and decided that that was far enough. (Our first bird to stop in Cuba.) Homer led us on a merry chase, which included migrating through NC three times on the same migration (see his maps for details)! Bluebeard made it all the way into Columbia and was on the home stretch of his migration when he disappeared. Suspiciously, our last signals from him were in an area with extensive human activity. We're quite sure he was shot. Jaws remained on his winter territory throughout 2005, although his transmitter went off the air in November, leading to much anxiety here at Osprey Central. (Maps)
In 2006, Thanks to the efforts of the staff and Friends of Cape Henlopen State Park, we expanded our project south and tagged three young Ospreys in Delaware. Rhode Island Audubon sponsored another transmitter for a bird in Jamestown, and we put another transmitter on a recent fledgling on Martha's Vineyard.
Meanwhile, Jaws was spotted flying north through North Carolina by a colleague in Wilmington in May, several months after I had deactivated his ID with the satellite company, ARGOS. A week after he was spotted, ARGOS contacted me to say that they were receiving intermittent transmissions from him and ask if we wanted his ID reactivated. We did indeed and had remarkable luck with his transmitter turning on exactly when we would have turned it on ourselves, had it been under our control. It came on just as he was crossing Rhode Island and landing on the Vineyard. Then it went off for a while, but came on in August, documenting his return to the very spot in eastern CT where he had spent a month prior to his first migration back in '04. This dovetailed beautifully with our observations of adults that commuted back and forth between freshwater areas in NY or CT and their nesting territories after a nest failure. It appears that some Ospreys have a favorite fishing hole in freshwater areas that they can rely on when the fishing is bad around the nests, and return periodically to the nests, 1-200 miles away to make sure no young upstart gets any ideas about the territory being vacant.
Jaws' transmitter went off for a while, but came on just as he was leaving FL and documented his trip across the Caribbean and return to the same general area where he spent his first year and a half in South America.
While Jaws was doing his first trip north and south, Homer had settled down in Venezuela, and Conanicus spent a year and a half in the Zapata Swamp on the south shore of Cuba.
The "Class of '06" provided some interesting new data. One of the DE birds made it as far as Savannah, GA, and decided that was far enough. Another headed south over the Atlantic from Bald Head Island, NC,--a route a fair number of birds take on a short-cut to FL, but this bird had a bit too much east in her internal compass and went down at sea about 150 miles from Turks and Cacos Islands in the eastern Bahamas. The third Delaware bird made it to the Amazon, where she is currently waiting out her year-and-a-half on the wintering grounds.
The two New England birds did not fare well. The RI bird, Comet, showed us a new route, heading due south from Cuba, passing over Jamaica before crossing the Caribbean the really long way, landing in Panama. From there he headed into South America, where we lost his signal in November. We don't know what happened--it may be a malfunctioning transmitter, or he might have died. Moshup, our lone Vineyard bird tagged in '06 settled down for the winter in the Dominican Republic and was shot in March by hunters who confused him for a Red-tailed Hawk (which they shoot because Red-tails will take chickens, and back-yard chickens are an important protein source for many in the D.R.) We were able to get his transmitter back, as well as the transmitter from the DE bird that was wintering around Savannah. We have no idea why he died, but West Nile Virus is always a suspect with birds of prey. Since the loss of this bird in a wooded area, we have had several others somewhat mysteriously die under similar circumstances. We now strongly suspect that Great-horned Owls have taken a number of our migrating Ospreys. When an apparently healthy bird in full migration spends the night in a large woods and doesn't come out the next morning, we take this as strong circumstantial evidence that a Great-horned Owl took down our bird. (Maps)
In 2007 we tagged five more birds--two in Delaware and three on Martha's Vineyard. Three of these transmitters are new, state-of-the-art GPS transmitters, two were the transmitters we recovered from Moshup in the D.R. and Lew near Savannah. Previous units provided locations that were at best within a hundred yards or so of the bird's true location, but often miles off. This level of accuracy is fine to study migration, but insufficient to really understand the fine details of migration and foraging ecology around the nests and wintering grounds. The new transmitters provide very accurate hourly locations, as well as speed, altitude, and direction of each fix. (Maps)
2008 was a busy
year! We tagged 7 young Ospreys. Duke was tagged on the Catawba River down in
Great Falls, SC; Little Ricky in Cape Henlopen, DE; Penelope, Mittark, and
Meadow on the Vineyard; and Sheri and Goody Hallett on Cape Cod.
In 2009 we continued tagging youngsters and initiated a new study of the foraging ecology of adult males. The new GPS transmitters are so accurate that we can now learn exactly where our birds are spending their time fishing. Six young (SC, RI, and MA) and four adult males (three on the Westport River in southeastern MA and one on Nantucket Island) were tagged. (Maps)
The 2010 season
began with tagging four more adult males. 2009 was going to be our last year for
the study of junvenile migration, but that didn't work out. Our Delaware
colleagues at the Friends of Cape Henlopen State Park had raised money for a
transmitter for a young bird in 2009, but their target nest did not produce any
young, so they deferred the deployment of their transmitter to 2010.
Additionally, we finally got Meadow's transmitter back, a year after the bird
was shot, so we had another transmitter to put on a young Osprey.
OOPS! Just discovered how behind the times I am on this page. Someday I'll catch up...