Migration - 2007
Migration home page
Status of our migration studies.
Old Birds: Updates
on birds tagged in '04, '05, and '06.
New Birds: I tagged
5 new fledglings this summer. I began with two in Delaware and then tagged three
on Martha's Vineyard. One of the Vineyard birds, Felix, was tagged at Felix
Neck, the Mass Audubon sanctuary on the Vineyard. The sanctuary has a long and
storied history with Ospreys on Martha's Vineyard (see the History section on
the main Osprey page).
This is the first year we have used GPS transmitters,
and the data are already showing us some amazing details of Osprey behavior.
migration websites (mostly raptors)
here to read the "bios" of the birds and notes on how
they were captured and see pictures of the Class of '07.
If you would like to be included in an email list to
receive a notice each time maps are updated, send me an e-mail: email@example.com
| New (and Old) Birds (click on the links below to
go to that bird's maps)
- First map
begins - Penultimate
map - Most
- First map
begins - Penultimate
map - Most recent
Brazil - Last
- First map
begins (Start here!) - Last
begins - Penultimate
map - Most
map - Penultimate
map - Most
map - Last
Spring Migration 2007
- Is back home for the first time and continuing his peripatetic ways!
- Back for his second trip home, now a 3 year old bird. His
transmitter seems to have finally given up. We hope we see him at a nest
next year, where we might be able to trap him and get the transmitter
- Our Rhode Island youngster from '05 started his migration from his
redoubt in the Zapata Swamps on Cuba's south shore, but did not even make
it all the way across the island.
- Our surviving Delaware bird is not migrating, but her month-by-month
movements are interesting. This link will take you back to Oct. 06 when
she stopped migrating. From there you can browse her monthly maps.
This is the eighth year of our study of
Osprey migration. Since 2004 we have been concentrating on tagging
juvenile birds. The migrations of more than 150 adult Ospreys have been
documented in North America, mostly by Mark Martell during his time at the
University of Minnesota's Raptor Center. As a result we have a quite
detailed understanding of how and when adult Ospreys migrate. We know the
routes they take. Almost all east-coast birds go through Florida to Cuba
to Hispaniola and on to South America. Some New England birds think
Florida or the Caribbean islands is far enough south, while some Florida
adults, for reasons difficult to fathom, migrate deep into South America. Other
Florida adults stick around for the winter.
Adult females migrate about a month before
males, and adults of both sexes are very faithful to their chosen wintering
grounds. Because young experience a very high mortality rate and satellite
transmitters are very expensive, only a handful of first-year Ospreys had been
tagged prior to 2004, and thus their migration is poorly understood. When do
they go south? How do they find a reliable wintering area? Do they spend time
exploring or chose the first good spot they find? We know from traditional
banding studies that they stay on the wintering grounds for at least a year and
a half. Do they all return in their second year? Do they go all the way home on
their first return?
With five young tagged in 2006 and five to be
tagged in 2007, we will have tagged 15 fledgling Ospreys, which more than
doubles the number of first-year birds that have been tagged anywhere else, as
far as I know. By "cherry picking" young from old, established
breeding pairs, and trapping young that have already been flying for a couple of
weeks, we have significantly beaten the odds--only one of the five young tagged
prior to this year did not make it to the Caribbean.
The Class of '04: On his migration south
in the fall of 2005, our only tagged adult Bluebeard was shot (almost
certainly) just a couple of hundred miles north of his wintering grounds. That
left only Jaws, a fledgling tagged in 2004, as a candidate to return to
Martha's Vineyard in the spring of 2006, and his safety was in question as the
year began. Our last signals from him were in December of 2005, and those were
intermittent. We suspected a malfunctioning transmitter, given that he had been
in what appeared to be Osprey heaven down in Colombia, with lots of fish and no
one around that shoots Ospreys. Lo and behold, in May someone spotted an Osprey
flying through eastern NC (when Jaws should have been moving back for his first
trip home). In late May his transmitter turned on for a couple of days as he
arrived back in his natal area. There's some sort of problem with his solar
panel, so we only get very sporadic messages from him, but he's out there. Since
then, he has returned to the Gulf of Venezuela to spend the winter of 2006-07
and returned again to Martha's Vineyard in April 2007.
The Class of '05: Homer spent
a year and a half down south in Venezuela before heading home. Homer made it
back to the Vineyard, while Conanicus started migrating but never made it
to the north coast of Cuba, probably another victim of shooting.
The Class of '06: We didn't have much luck
with the 5 birds tagged in the summer of '06. Of the 2006 birds, only Della,
tagged in the Delaware Seashore State Park, is left. She is down in the middle
of the Brazilian Amazon and should return in the spring of '08. But this is
pretty much what we expect--mortality in first year birds is probably between 80
and 90% over their first migration cycle.
(Click on the bird's name to get to its most
- Tagged in '04, this young male is back on the Vineyard with a
mal-functioning transmitter. With luck, we may be able to retrap him next year
and get the bad transmitter off him. We haven't had any signals from his radio
(nor any sightings) since May 6th. We hope he'll show up at a nest next year,
where we may be able to trap him and get the radio off his back.
- After turning a 3,500-mile migration into a 5,200-mile odyssey (he was
named for the pond near his nest, not in anticipation of his extended travels!),
Homer finally (March '06) settled down at a reservoir to his liking and in April
was making occasional trips some 30 miles to a mountain valley west of his
reservoir. He has shown a predilection to mountain rivers throughout his
migration. He arrived back on Martha's Vineyard on 20 May, 2007, a couple of
weeks after his second "hatchday".
- Our Rhode Island youngster, tagged as a recent fledgling in '05, frequented
the Zapata swamps in southwestern Cuba for a year and a half. He began his '07
migration on the 29th of April and sadly ended his trip at a fish farm.
NEW BIRDS for 2007
This year's trapping began on 25 July at the SPI-Pharma
facility next door to the Cape Henlopen State Park (CHSP). CHSP and the Friends
of Cape Henlopen are sponsors of the two Delaware transmitters this year. (As
above, click on the bird's name to go to its migration maps.)
- I grabbed this young male off his nest atop an 80' water tank at the PSI
Pharma facility that makes milk of magnesia from water taken from below CHSP.
The nest is rigged with a camera that feeds to a TV monitor at the State Park
Nature Center a half mile or so away. His sibling, hatched a full week after
Claws, was not ready to fly. As it turned out, Claws could indeed fly, he just
didn't know it yet.
||We took him down to ground level where we banded him
and outfitted him with his new GPS transmitter. When we returned him to
the nest, he leapt off the nest and sunk his talons into Holly Niederriter,
a DE Division of Fisheries and Wildlife Biologist who was helping me out. I was
already half way down the ladder when this happened. Holly pried the bird
off her and put him back on the nest. We gave her naming rights for the
ordeal, and she chose, appropriately enough, "Claws".
The next morning Claws was on the tower, but not
in the nest, which is on a platform several feet above the top of the
tower. I went up to make sure he was OK, and when I got to the top of the
tower he took one look at me and decided he was more scared of me than he
was of flying, so I got to watch his first flight. He flew beautifully
around the tower for
a few minutes. His landing on an adjacent tank was not so
beautiful, as first landings often lack much grace. Later that morning he
was in the nest, seen on the TV down at the Nature Center.
- This young female was tagged in the Delaware Seashore State Park, south of
Dewey Beach, just a mile or so north of the Indian River Inlet. The nest is the
neighbor of the nest where we tagged Della in '06.
||Patience and her sibling were already flying and
probably had been on the wing for at least a week. We arrived around 2PM
and set up our noose carpet with a couple of fresh mackerel under it.
Within fifteen minutes we caught the adult male, who landed on the nest
and tried to grab the fish, getting his talons tangled in the nooses in
the process. We quickly got him off the
noose carpet, banded and released. Fifteen minutes later we caught an
adult female, which we likewise removed from the trap. It turned out she
had been banded as a nestling 2 years before close by. When we caught her
we thought she was the adult female at this nest.
An hour later we caught the real adult female at the nest--setting a
record for most Ospreys caught that we didn't want to catch, and realized that
the first female we caught just happened to be flying over and, seeing the two
fish in the nest, decided that if no one else wanted them, she'd help herself.
At about 4PM the two young landed on the corners of the
nest (not on the noose carpet) and just sat there. We watched them for 3 hours,
as they preened, occasionally looked at the fish, and sometimes begged for food.
Clearly these youngsters are spoiled rotten. A bit after 6 the adult female
landed on a third corner of the nest and sat there for about 45 minutes.
Eventually, the screaming young got to her, so she hopped down on the fish to
feed them. At that point the hungrier of the two young landed near her and
walked over to her, getting caught in the process. After the long stake out,
CHSP's Director of Environmental Education, Richard Julian, suggested the name
for this bird, who is now wearing the transmitter I recovered from one of the DE
birds tagged last year.
On the 26th I flew to Martha's Vineyard for the final leg
of the trapping trip.
- Early on the 27th, Dick Jennings and I set up our noose carpet at the
Mink Meadows nest on the Vineyard's north shore. This has been one of the
most productive nests since I re-started the Osprey census in 1998 and
this year fledged two young. When we set up at 0630, there was not an
Osprey in sight, which made us needlessly nervous. Around 8 we had an
adult show up and by 9:15 a young bird landed on the nest and was caught.
We tagged this bird with a GPS transmitter. The bird is named in memory of
John Luke, a great friend of my family and a devoted Ospreyphile who lived
in the Mink Meadows Osprey's backyard--or is it vice-versa?
- On the 28th we set our noose carpet on the nest at Mass Audubon's Felix Neck
Wildlife Sanctuary. Mass Audubon has been a great supporter of the tracking
work, kindly processing all our finances, and the 60-70 Ospreys that now nest on
the Vineyard are pretty much there because of the efforts of long-time Sanctuary
Director Gus Ben David. Gus, who retired a couple of years ago, and his Osprey
crew are responsible for most of the 115 nest poles on the Island, so it was an
obvious place to tag a bird, and the name was similarly easy to come up with. We
were ready with "Felicity", had our bird turned out to be a female. In
fact, we're not completely sure we shouldn't have used Felicity to name this
bird. Female Ospreys, like all birds of prey, are larger than males. It's pretty
obvious when you have a small male or a really large female, but sometimes the
intermediate birds are a bit tricky to sex. Let's just say I wouldn't be
completely surprised if Felix comes back to the Vineyard in 3 or 4 years and
lays some eggs!
||Here are a couple of shots of setting the noose
carpet as we prepared to trap Felix, courtesy of Rick Solberg.
Trapping went fairly smoothly--no
problems with catching adults this time, and that was a good thing! The nest in
Delaware, where we caught 3 adults, was only about 12 feet off the marsh, so it
was no big deal to throw the ladder up to the nest and extract our birds. The
Felix Neck nest is about 40' high, so I have to use a ladder to go up the first
20' and then pole spurs then next 20'. I did not want to do that for anything
other than our target youngster, so we were ready to run up to the nest and
deflect any adults that came in on a landing approach.
We did have to wait until 11 for any action, because
when we arrived at 6AM to set up, breakfast was being served in the nest. The
early bird gets not only the worm, but occasionally the fish as well, it would
appear. One of the two young was around the nest most of the morning, but not
particularly hungry, having had sushi for breakfast. It made a few passes at the
nest, but was put off by the noose carpet and flared off just before landing.
Felix spent the latter part of the morning over on an
unoccupied nest pole, about 100 yds from the nest pole, waiting for Dad to bring
home a fish. Around 11 Dad did come home with an early lunch and went over to
land on the spare pole where the youngster was waiting. That would not have
helped us, so we flushed the adult male a couple of times as he tried to land on
the pole. After getting bumped off the pole the second time, he flew over to the
nest and landed on it, fish in talons. Felix flew over to him and got snagged in
the carpet around 1115. He is now wearing a GPS transmitter.
-- Our last transmitter was placed on a full sibling of Moshup, the
youngster we tagged in '06 at the very productive Lobsterville Nest, which
is located out on the southwest corner of the Island. Informed sources
tell me that "Conomo" means plenty of fish in the local Amer-Indian
(Wampanoag) dialect, so it's a hopeful name for the bird. This trapping
session went pretty smoothly, and we had our bird in hand again at 1115.
The year before we had to wait until about 2PM before we caught Moshup. We
recovered this transmitter after Moshup was shot in March down in the
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