Peril overcome, an American Oystercatcher returns home to Milford Point
In the sanctuaries …
July 12, 2022 — Life for the birds nesting on the Milford Point sandbar is always fraught, and the summer of 2020 was particularly perilous for the American Oystercatchers there.
High tides made even higher by coastal storms flooded nests. Two young birds survived only because their mother ratcheted up her maternal instincts and protected her eggs as the tide rose.
One of those hatchlings got its head tangled in a piece of plastic that probably would’ve prevented it from eating enough to survive. That bad luck however led to a key bit of information about bird migration and the importance of the Milford Point habitat.
The bird was too young to fly, so three staff members from Connecticut Audubon, and a colleague from Audubon Connecticut, were able to safely trap it and remove the plastic.
Then they fit its leg with an identification band.
These lightweight leg bands are issued by the U.S. Geological Survey and each has a unique color-number identification combo. We have several federally-licensed banders on our staff and among our volunteers and colleagues.
If and when someone sees a bird wearing a leg band, and reports it to the USGS, it adds one important piece of information about the movements of migratory birds to the scientific record.
In July 2020, the rescued oystercatcher was fitted with a yellow band, ID number N29. Its sibling was also banded, with number N28.
On July 1, 2022, Imani Rodriguez, who is working for Connecticut Audubon this season as a coastal ranger at Milford Point, reported an oystercatcher with a leg band.
And yes, it was N29.
The American Oystercatcher that survived only because its mother protected her eggs from a high tide, and because we were able to remove a length of plastic from its head, had returned to the place where it hatched.
Where had it been over the past two years? Further south. N29 was reported from Seabrook Island, South Carolina, in December 2021 and less than two months ago, in May 2022.
Breeding American Oystercatchers usually arrive at Milford Point from the south in March.
Migrating oystercatchers begin to gather there in July to prepare for southward migration. We’ve always assumed those birds came from the north.
But N29, a two-year-old too young to breed, came from the south on July 1.
(Its sibling, N28, the bird hatched from the other egg protected by the mother in July 2020, also showed up at Milford Point recently, although there’s no other sighting data on record to let us know where it had been.)
So does that mean Milford Point is a gathering place for American Oystercatchers from the south as they prepare to migrate?
Why would a bird that is already in the south fly to Connecticut in July to then migrate south again?
No answers yet, of course. But we’ve always known that Milford Point was a critical area for migrating shorebirds. The data from N29 might possibly indicate that it is important in different ways than we had thought.
Oystercatchers might gather there from various points on the compass to form pair bonds for future breeding. They might gather there to benefit from the safety in numbers.
That’s speculation, of course. N29 (and N28) provided just two small points of information.
But no matter what, you have to admire the tenacity. Storm tides, dangerous plastic debris, long migrations. N29 survived them all and managed to return home.