Published on September 23, 2021

Mass Audubon Islands 2021 Shorebird Monitoring Summary

Every year during the summer breeding season, Mass Audubon's Coastal Waterbird Program (CWP) conducts shorebird nest monitoring field studies on both Martha's Vineyard and Nantucket. We're pleased to share a summary of this season's results from both locations.

Martha's Vineyard Season Summary

A Piping Plover searches the shoreline at a beach while children play nearby

The CWP team at Felix Neck, comprised of staff and volunteers, monitored Piping Plovers, terns, and American Oystercatchers at 18 sites on Martha’s Vineyard during the 2021 nesting season.

Over the course of the season 11 pairs of Piping Plovers successfully fledged six chicks with a final productivity of 0.55 fledglings/pair. The regional recovery goal set by the U.S. Fish & Wildlife Service for Piping Plover productivity is 1.5 fledglings/pair. Although this season’s productivity rate fell short of the regional recovery goal, more chicks fledged than last year with a significant increase in productivity up 0.55 chicks/pair from 0.33 in 2020.

There were 13 American Oystercatcher pairs observed on Mass Audubon-monitored sites during the 2021 season. Of these 13 pairs, nine of them fledged a total of 13 chicks. This season’s American Oystercatcher productivity rate was 1.0 fledglings/pair, greatly exceeding the recovery goal of 0.5 fledglings/pair.

Throughout the season approximately 200 Least, Common, and Roseate terns were observed across our 18 sites. Unfortunately, no chicks successfully fledged this season. According to monitors' observations, the leading causes of nest loss was tidal overwash and predation, although many nests failed due to unknown causes. However, the suspected predators for most of the failed nests were American Crows and skunks.

The Coastal Waterbird Program staff educated the island community through informal interactions during site visits and formal educational programming. The educational programming, geared towards a wide variety of audiences, included shorebird fencing tracking lessons with preschoolers and collaboration with the "Creature Feature" event at Mink Meadows. Approximately 40 people participated in educational programs offered by Mass Audubon's Coastal Waterbird Program on Martha's Vineyard in 2021.

Studies have shown that even the presence of a dog on a beach causes Piping Plovers, terns, and American Oystercatchers immense stress that negatively impacts their ability to nest and fledge chicks. Although dogs are not allowed on many beaches from April 1 through September 1, dogs and/or dog tracks were observed on nearly every site this season. To protect shorebirds from both dog and human disturbance, fencing was erected around historic nesting habitat and active shorebird nesting.

You can help protect endangered shorebirds in future seasons by respecting the rules of beaches that prohibit dogs during the shorebird season, and, when dogs are allowed, make sure to leash your pet and walk along the water’s edge.

Nantucket Season Summary

American Oystercatcher adult with its chick on a beach © Cameron Darnell
American Oystercatchers © Cameron Darnell

Mass Audubon's Nantucket CWP team regularly monitored 12 sites for protected bird species during the 2021 season.

On Nantucket and Muskeget Islands, 19 pairs of Piping Plovers successfully fledged 13 chicks with a final productivity of 0.68 fledglings/pair. Four American Oystercatcher pairs were observed on Mass Audubon monitored sites and successfully fledged six chicks with a productivity of 1.5 fledglings/pair.

At the season’s peak approximately 650 Common, Least, and Roseate terns were observed on Mass Audubon monitored sites. Unfortunately, no chicks successfully fledged this season.

Similar to the sites monitored on Martha’s Vineyard, the leading cause of nest loss across our species of concern was predation and tidal overwash, but the majority of nest losses could not be conclusively determined. American Crows have been identified as the primary predator for shorebird nests and were regularly observed at many sites.

High presence of crows on beaches makes it all the more important to limit human disturbance to nesting birds. If people pass too close to nesting areas, birds often become stressed and leave their nests, making them vulnerable to predation. Keeping your distance and not lingering near fenced areas can help to ensure that birds do not abandon their nests.

Although terns did not successfully nest on Muskeget this past season, flocks of terns in the hundreds used the area for staging after completing their nesting season in New England. Staging is an important step in shorebird migration when flocks of birds rest and feed before flying south. In fact, this year we partnered with the National Audubon Society’s Seabird Institute to establish a sensor on Muskeget that would scan for terns that had been tagged in Maine and New Hampshire earlier in the year. The findings of the study will help us better understand the importance of Muskeget as a staging destination in the region for terns preparing to migrate for the winter.

If you see large groups of birds resting along the shore in the late summer, they are likely staging. Even though the nesting season may be over you can still help protect endangered shorebirds by giving them space. They have a long journey ahead and need all the energy they can muster to propel them up to 4,000 miles away to central and southern America where they will overwinter.

Stories From the Field

Beach debris was also a threat to nesting birds in 2021. On June 23, a Piping Plover chick was observed swallowing a balloon string. The chick was the smallest of the brood and was not foraging as actively as its siblings on multiple visits. While the chick was able to overcome the odds and survive to fledge, it is recommended that CWP staff continue to educate beachgoers about keeping the environment clean to protect nesting birds.

Just as climate change has greatly impacted coastal communities with more frequent and severe storms, it also affects nesting shorebirds.

Tern colonies at State Beach and Haystack Island, Piping Plover nests at Quansoo and Mink Meadows, and an American Oystercatcher nest at Sarsons Island were all lost during the storm on Memorial Day this year. Exposure during adverse weather may have also led to American Oystercatcher chick losses at other sites. Storms directly affect nests and erode valuable habitat, so the role of CWP staff will be increasingly important to help shorebirds succeed.