You CAN Go Home Again: Researchers have learned that American Oystercatchers return to the same locations. Two birds are loyal to the sandbar at Milford Point
Jay Gil was birding at Milford Point on May 2 when he photographed this American Oystercatcher. The band identifies it as N29, which hatched in 2020 and barely survived. Photo courtesy of Jay Gil.
By Johann Heupel
August 25, 2025 — Each fall, thousands of shorebirds migrate south from their breeding grounds to warmer climates. Some, like the Red Knot, travel an astonishing 18,000 miles each year; others, like the American Oystercatcher, make shorter journeys along the Atlantic and Gulf coasts.
Many shorebirds show remarkable site fidelity, returning year after year to the same beaches to breed, rest, or spend the winter. To study individuals, researchers band them with unique color-and-number codes — a small piece of plastic that makes one bird distinguishable from a flock of lookalikes. These leg bands open a window into the private histories of individual birds.
I would like to share the fascinating stories of two birds that nest in our coastal sanctuary at Milford Point, remarkable yet modest birds that brave the predators and elements year after year to raise the next generation. They are both American Oystercatchers, a beach-nesting species that calls the shores of Connecticut home for the breeding season, from spring until early fall.
Of the many oystercatcher chicks that hatched in June 2020, one at Milford Point became entangled in a synthetic fishing net, leaving it unable to move freely and vulnerable to predators. A team of shorebird monitors and researchers from Connecticut Audubon and our colleagues at Audubon Connecticut rescued the chick and cut it free from the wire.
Beth Amendola of Audubon Connecticut took the opportunity to band the chick as N29. They released the bird back to the sandbar and watched it grow to the point where it migrated south in the fall. It was seen over a year later, overwintering on Seabrook Island in South Carolina. N29 returned in 2022 to the rocky foraging grounds near Milford Point, which are a crucial staging area for the birds to find oysters, clams, and mussels to eat during fall migration.
Members of Connecticut Audubon’s field staff, Kat Gillis, left, and Stefan Martin, worked together in 2020 to free a young oystercatcher caught in netting. Beth Amendola of Audubon Connecticut then afixed a yellow band, N29, to its leg. CTAudubon photo by Patrick Comins
After several years of being sighted bouncing between Connecticut and various islands in North and South Carolina, N29 returned to the Milford Point sandbar for a different purpose in 2024 – to attempt to raise young of its own. It made several nests over the year, each one destroyed by predators.
We coastal monitors work to fence off areas where eggs are laid, but the amount of protection afforded depends on the species. For the smaller Piping Plovers, wire cages can keep predators out, a strategy that has dramatically increased the number of young plovers hatching each year. Unfortunately, these “exclosures” cannot be used for larger birds, leaving American Oystercatcher nests vulnerable to foxes, raccoons, crows, and other egg predators.
Although we were happy to see N29 return this year (a visitor, Jay Gil, photographed her on May 2) the result was the same. N29 made four nests – predators destroyed each before the eggs could hatch.
That lack of success is not unique in Connecticut. Quite the contrary. And it has led to an interesting shift in nesting tactics. The frequency of predation on oystercatcher eggs on mainland beaches has forced this species to nest on the islands off the coast of Connecticut, where they generally have more success.
The Audubon Alliance for Coastal Waterbirds tracks oystercatcher breeding in the state; the number has continued to increase over the years, from a scattered 46 nesting pairs in 2011 to a substantial 92 pairs in 2024, of which around 80 percent were located on the coastal islands.
Yet there are still birds that manage to successfully mate on the mainland beaches of Connecticut, including one that has called Milford Point home for many years.
This American Oystercatcher, with the leg band 3T, has been observed at Milford Point for eight years.
The bird known as 3T has always been a character at Milford Point. A female that has nested on the sandbar for at least eight years, she was banded in 2018 and is easily recognized by both researchers and volunteers. Fiercely defensive of her territory, 3T will drive off other oystercatchers with such intensity that she has even injured rivals that ventured too close.
That protectiveness, however, sometimes works against her, as she has been known to leave her own eggs unattended in the heat of battle. Despite these challenges, she has produced several chicks over the years.
The last few seasons have been grim for oystercatcher breeding on the sandbar: none of the oystercatcher eggs managed to hatch in 2024 because of predation. The breeding season this year began similarly, with the constant presence of foxes resulting in the loss of over 20 nests (oystercatchers will try repeatedly if their nests are destroyed, so these 20 lost nests came from 5 pairs of would-be parents).
Against those odds, 3T became the bright exception. One of her eggs hatched, and the chick not only survived, but took its first flight on August 5 – a hopeful note in the struggles of our breeding birds.
Over 20 years ago, the decline in American Oystercatchers in North America to around 10,000 birds alarmed conservationists, sparking a flurry of initiatives aimed at discovering why they were disappearing. Before long, the findings of the new American Oystercatcher Working Group were turned into a comprehensive action plan to coordinate efforts to increase their population by 30 percent over the following 10 years. Oystercatchers have increased by almost 45 percent since 2008, the year their action plan was released.
There have been at least 75,000 sightings of the over 6,000 banded oystercatchers across the United States and Mexico, documented by researchers or volunteers. By standardizing banding practices and compiling a database that tracks the movement of banded oystercatchers, the working group has significantly enhanced our understanding of their migratory patterns and breeding behavior.
We have learned that the site fidelity shown by N29 and 3T is common, both in their breeding and overwintering areas. Although this is interesting to understand, the question remains —why is it so important to know where these birds breed year after year?
That knowledge can be used to guide efforts to preserve and restore habitat in the key areas where the birds are naturally inclined to return. Although American Oystercatchers can live for up to 17 years, they are unable to reproduce and survive if the beaches and islands of the Atlantic coast continue to be disrupted by development.
The stories of birds such as 3T and N29 may be ordinary for their species, yet they teach us more about how we can help this remarkable bird thrive along our coasts.
Although it may have a better chance at success on one of our offshore islands, as long as N29 continues nesting at Milford Point, we will do our best to help it succeed as we do with our Piping Plovers.
To learn more about the research of the American Oystercatcher Working Group or to report a banded oystercatcher, please visit their website at https://amoywg.org/.
— Johann Heupel is a coastal monitor for Connecticut Audubon. He has teamed with Matt Joyce to protect birds at Milford Point for the last three nesting seasons.
