An American Oystercatcher in Flight (photo courtesy of Vernon Laux).
In our last blog post, we discussed the many preparations currently underway in our Science and Stewardship Department for the arrival of our seasonal field assistants and the start of the 2013 field season. Although many of our vegetation-related projects do not get underway until plants begin to bloom and leaf out in late spring, our wildlife monitoring work often begins when it still feels like winter outside. One of the earliest projects we initiate every year is shorebird monitoring, and one of the first species to arrive on Nantucket to herald the beginning of the breeding season is the American oystercatcher (Haematopus palliates). The first oystercatcher to arrive on Nantucket in 2013 was observed by our colleague, Edie Ray, on March 3rd on the rocks of the west jetties entrance to Nantucket Harbor. Since then, numerous additional birds have come back to our island from their wintering grounds in the southern United States. Let the season begin!
During the spring, summer, and fall, the American oystercatcher is a common sight on Nantucket’s beaches, tidal flats, and salt marshes. This large, conspicuous shorebird has a long, bright orange bill, bright yellow eyes, and sharply-contrasting brown, black and white plumage. Its preferred prey is mollusks, marine worms, and shellfish obtained while feeding along the shoreline and tidal flats. Oystercatchers begin laying eggs in late March. They nest directly on the open beach or in patches of sandy habitat within salt marshes. Both parents incubate 1-3 eggs, which hatch after about 3 weeks. The chicks learn to fly within 4 weeks of hatching, and family groups usually remain together long after the breeding season has ended. Oystercatchers often linger on Nantucket until late fall or early winter – in fact, it is not unheard of for them to be sighted on Nantucket’s Christmas Bird Count in late December.
An oystercatcher chick hiding in the marsh grass at Medouie Creek.
On NCF properties, American oystercatcher nesting sites are found at Coatue, The Haulover, Eel Point, Pocomo, and Medouie Creek. Our Science and Stewardship Department hires a seasonal field assistant each year to monitor and protect the oystercatchers, piping plovers, and least and common terns that nest on our beaches. This year, Mara Plato will be joining our seasonal staff to fill this important role, and will be working closely with Danielle O’Dell and Karen Beattie from our year-round staff. Our Coatue Ranger is a key participant in these efforts, and this year we are fortunate to have Jonathan Shuster, a former NCF shorebird monitor from 2011, coming back for this position. We also regularly communicate with numerous colleagues working on abutting conservation properties and town-owned beaches to gain information about the island-wide population of this species.
Jonathan Shuster monitors oystercatchers at Coatue Point.
Although American oystercatchers are not legally protected under either the Massachusetts or Federal Endangered Species Act, the U.S. Shorebird Conservation Plan (produced by Manomet Center for Conservation Sciences in 2001) identified oystercatchers as one of several species with declining populations in need of special attention. As a result, the American Oystercatcher Working Group (consisting of federal, state and non-governmental agencies and scientists responsible for managing this species) was formed to address research and management priorities. One of their first actions was to conduct a complete population estimate of wintering American oystercatchers in 2002-2003 using a combination of aerial surveys, photography, and ground counts along the contiguous coastline starting in New Jersey and ending in Texas. As a result of this work, the range-wide population of this species was estimated at only 11,000 birds. The survey was just repeated this winter to detect population changes, but results are not yet available.
American oystercatchers on their wintering grounds in Cedar Key, Florida.
For the past six years, our Department has been one of many partners participating in the American Oystercatcher Working Group’s mission “to develop, support and implement range-wide research and management efforts that promote the conservation of Atlantic coast American Oystercatchers and their habitats.” This includes collaborating with researchers along the Atlantic coast on a coordinated, widespread effort to band and re-sight oystercatchers to learn about their complex patterns of movement and dispersal. There are currently active color-banding and/or re-sight projects underway in Massachusetts, New Jersey, Virginia, North and South Carolina, Georgia, Florida, and Texas. The color-bands used contain a unique 2-3 character code with a color combination specific to the state where the bird was banded (Massachusetts bands are yellow with black codes). Researchers are thus able to identify and track individual birds in the field without re-capturing them.
As a result of the hard work of many colleagues, a large percentage of Nantucket’s oystercatchers are now individually color banded: of the 21 pairs that nested on NCF’s beaches during the 2012 season, 22 adults and 7 chicks were banded. Oystercatchers can be extremely long-lived – it is not uncommon for birds to live at least 10 years, and there are records of banded individuals surviving up to age 17. Therefore, color banded individuals are often re-sighted for multiple years on both the breeding and wintering grounds. This data provides invaluable information about nest site fidelity (the tendency to return to the same breeding site), movement patterns between wintering and breeding ranges, and many other important population trends. Breeding birds banded in Massachusetts have been re-sighted in Connecticut, New Jersey, Maryland, North Carolina, South Carolina, and the ocean and gulf coasts of Florida. Conversely, birds banded in New Jersey, Virginia, North Carolina, South Carolina, and Georgia have subsequently been observed here in Massachusetts.
A specific, local example of how this research can reveal some very interesting and remarkable information came to light last year. “E2”, an oystercatcher that was banded in July of 2005 as an adult bird nesting on NCF property at Eel Point, has been observed for several years wintering in Cedar Key, Florida (on the Gulf coast just southwest of Gainesville). On Monday, March 19, 2012 at 12:30 PM, Charlie Muise (a researcher from Georgia visiting Cedar Key with his family) observed E2 feeding with a group of 24 oystercatchers. On Friday, March 23, 2012 at 11:30 AM, Danielle O’Dell observed E2 back on its nesting territory at Eel Point with several other oystercatchers. The straight line distance between these two sites is 1,109 miles; therefore, E2 travelled an average of 277 miles per day (at least) on its journey back to Nantucket! Needless to say, we are eagerly watching and waiting for E2’s arrival this spring.
This oystercatcher, C1, is one of several birds that nest on Nantucket and have been observed during the winter in Cedar Key, Florida (photo courtesy of Patrick Leary).
If you are out and about on Nantucket’s beaches this season and observe a color-banded American oystercatcher, please call us with the code and the date, time and location where you saw it. As demonstrated by Charlie’s re-sight report described in the paragraph above, this data can lead to some extremely valuable information. Check out the American Oystercatcher Working Group’s excellent website page, which contains all kinds of information about this species, including a detailed explanation about how to identify banded birds. This site also contains a recently-launched portal for entering color band re-sight information and finding out more about where each bird was banded and subsequent re-sightings. Massachusetts banding data has not yet been uploaded to this new website tool, but this is expected to happen within the next several months. However, NCF’s Science staff are familiar with most of our local banded birds and can likely provide you with information – so please call us (ask for Danielle or Karen) with your observations!
**Update!** Two of our banded oystercatchers have returned to our beaches! Danielle O’Dell saw E2 and its mate with black/yellow/silver bands at 10:30am on March 27th at Eel Point! Let the fun begin!