Black Crowned Night Heron on Boston Harbor Islands
Black-crowned Night-Heron chick and eggs.

Carol Lynn Trocki

Birds on the Islands
Field surveys have identified more than 200 bird species including gulls, terns, herons, ducks, geese, hawks, plovers, sandpipers, doves, owls, woodpeckers, and perching birds. During migration, large numbers of shorebirds utilize the mudflats and salt marshes around the harbor, while transient hawks and songbirds regularly make use of the more remote islands, or those with suitable habitat. In late fall and winter, great flocks of waterfowl gather in harbor waters.
2010 Field Season Summary Cover

Inventory & Monitoring
Birds are an important component of park ecosystems, and a good indicator species of local and regional ecosystem change. Researchers finalized a protocol to obtain information on the relative abundance of coastal breeding species at Boston Harbor Islands. With the assistance of volunteers, they estimated or directly counted all nests, incubating adults, or territorial nesting pairs on all islands where waterbirds have been known to nest in the past. Visit Northeast Temperate Network to view the protocol, annual reports, and to learn more about the birds in the park.

A European Rabbit is caught on camera while burying domestic quail eggs in a dummy nest. Did this happen to the tern eggs?

Lauren Nolfo-Clements

What Happened to the Terns on Lovells Island?

Historically, Lovells Island supported a breeding colony of Least Terns (Sternula antillarum), but during the 2007 breeding season the colony suffered a complete decimation. Volunteer monitors noticed that some nests had been attacked by predators. In an effort to uncover the culprit, motion sensing and infrared detection remote cameras were set near the nesting area, where scientists placed dummy nests baited with domestic quail eggs. It appears both mammalian and avian species, including American Crow, rats and European Rabbits were identified as nest destroyers and predators. The terns did not return to Lovells in 2008 or 2009, but in July 2010, scientists counted 35 Least Tern nests. On August 1, 2010, 10 fledglings were counted near the nests. The colony was active in 2011 with 75 nests detected in June, and in July there were 35 adults, several chicks and fledglings spotted, suggesting good productivity. In 2012, a colony returned in early June, but nests were washed away in a storm. Despite a second attempt at nesting, the colony was unsuccessful.

Massachusetts Department of Conservation and Recreation is working to improve Least Tern habitat on Lovells Island. In early April 2013, the park's Stewardship Saturday crew and volunteers from State Street worked to clear the beach of vegetation, making it more hospitable for the nesting pairs.

» Tern Predation Study (PDF - 448kb)

Tern nest after a rainstorm
This is a tern nest after a rainstorm.  Can you see the outline of the adult tern that protected the eggs and kept them dry?

Carol Lynn Trocki

Last updated: February 26, 2015

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