• Lush vegetation on the top of Spectacle Island's North drumlin dominates the foreground. Boston's skyline can be seen in the distance.  The park's logo with tag line minutes away, worlds apart empashises the stark contrast between the city and islands.

    Boston Harbor Islands

    National Recreation Area Massachusetts

Color Banding American Oystercatchers

Sean Murphy
Sean Murphy
College of Staten Island
(718) 982-4209
e-mail author
 
Delivered at 2008 Boston Harbor Islands Science Symposium.

The American Oystercatcher (Haematopus palliatus) has experienced a dramatic range expansion along the Atlantic Coast, reaching Massachusetts only 40 years ago. The Massachusetts' population continues to grow with the largest concentrations occurring on the islands associated with Cape Cod and Boston Harbor. At the same time, recent evidence shows this species is declining in its core areas and has recently been named as a species of concern by the US Shorebird Plan. From 2004 to 2007, 115 adult oystercatchers in Massachusetts were captured and individually marked using a coded color band in an effort to estimate critical demographic parameters.

As of spring 2008, 92% of the marked adults have been observed at non-breeding sites. Observations of marked birds have been recorded along the U.S. Atlantic and Gulf Coasts providing information on the movement of the population. Furthermore, mark-resight models employ return rates to estimate a minimum adult survival of 0.82 (0.028 SE). Oystercatchers nesting on the Boston Harbor Islands contain one of the northernmost breeding populations.

In 2009, we anticipate expansion of the color banding study area to include the islands of Boston Harbor. In order for the state to develop effective conservation and management techniques for this species, it is important to better understand the role of the Boston Harbor population in the total state population. Auxiliary markings will continue to provide information about the biology of oystercatchers in Massachusetts, but it is contingent on the reporting of resights by researchers and the public along the Atlantic Coast.

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