Least terns have nested on the Vineyard for as long as I can remember. According to Ludlow Griscom and Guy Emerson, the least terns of the Vineyard were able to avoid “plume-hunting persecution” of the 1800s. They nested successfully along what was termed Great South Beach and at Cape Pogue in the 1900s. No doubt the plume hunters were not willing to walk for miles in soft sand for a few plumes. However, least terns have not fared well on the Island since skunks were introduced, off-road vehicles are a dime a dozen and dogs accompany the family to the beach.
These days the number of least terns nesting on South Beach from Wasque to Squibnocket as well as along a few sandy beaches of the North Shore varies annually. Chappaquiddick’s east-facing beaches have also provided good habitat for these colonies. These smallest of our terns are very fickle about their nesting sites and often, if something irritates them, they move all at once, leaving their eggs and chicks on the abandoned site. Needless to say, the chicks and eggs do not survive.
As a youngster I can remember small colonies of 10 to 15 pairs along South Beach by Black Point Pond and another larger colony by Crab Creek on Tisbury Great Pond and yet another on the West Tisbury side of the Great Pond. However, these colonies never seemed to be in exactly the same place year to year. Now these colonies no longer exist. Least terns tried to nest by the opening of Tisbury Great Pond this year and failed due to a combination of storm wash over, dog and human interference and skunk predation.
Why then has the least tern colony at Norton Point in Katama hosted 40 per cent of the state’s least tern population this summer? And why has this same area hosted 50 or more roseate terns, which are an endangered species, to create the fourth largest concentration of nesting roseates in the state?
The answer is simple: a two-foot high fence around the whole tern colony, limitation of vehicular and human traffic and a crew of devoted tern techies who put up the fences, patrol the beaches and record nesting activities.
It all started in mid-May when a crew from the Trustees of Reservations took three days to dig a trench six inches deep around an area about the size of three football fields in order to bury the base of the 24-inch-high fence to enclose the tern nesting area. They also built what are called exclosures for three of the five pair of piping plovers that had arrived, bred and chosen the area to lay their eggs and raise their young. Other structures were placed within the fenced area — small teepees made of snow fence (know as tern condos) and pvc pipe partially buried in the sand provided shade as well as protection from the elements and flying predators for the young terns and plovers. Least, roseate and a few common terns were occupying the area that was being fenced, as were two more pairs of piping plovers. The Trustees crew decided that to put up plover exclosures in the tern colony would be disruptive, so they chose to let those plovers fend for themselves.
All was going well until the northeast blow and storm surge in June that caused the ocean to wash over the beach and wipe out many of the least tern nests, not only at Norton Point, but on most Island beaches where small least tern colonies existed. It also wiped out the three piping plover nests in the exclosures at Norton Point. Part of the fenced-in tern colony was not affected by the June storm and those terns did well. The terns that lost their nests moved outside the fencing and started nesting again. The piping plovers did not re-nest. This meant that the Trustees had to put up more fencing. This time a plow was brought in from off-Island and what had taken a few days in May just took a few hours. Another trench and more fencing were completed in short order. The terns and plovers were joined by three pairs of American oystercatchers, all residing inside the fencing.
What amazing results — 1,500 terns, mainly least with a few common and around 50 roseates, successfully nested and fledged 155 young as of July 26. This is a rough count from outside the fence and does not include the youngsters hidden in vegetation or in the tern condos or pipes. This productivity is excellent. It means that Norton Point probably will have been a nesting site for more than 80 per cent of the least tern productivity in the state. The two piping plovers inside the tern colony without exclosures were the only successful breeders — fledging two birds. Of the three American oystercatchers, one pair fledged three and the other two, two each.
I went out to inspect the project and was amazed at the whole setup. Not only were the birds successful, but the area that had been bare sand now sported new growth. I am sure this vegetative cover is the result of all the tern guano. The plants that are growing will provide important stabilization for this part of the barrier beach as well as cover for the young birds. I discovered that all three species of terns came from both the Vineyard and Chappaquiddick to use Norton Point to nest because of the food availability and protection. An experiment by the Trustees has shown that we can help endangered species (roseate tern) and species of special concern (least and common terns) by limiting access and controlling predation. We can still use a good portion of the beach and be proud that we are one of the best in the sites for breeding terns in the state.
If I were a tern — least, common or roseate — I would choose Norton Point as a place to nest. It is right next to the breach between Katama Bay and the Atlantic Ocean so there is great fishing. My nest will be protected from skunks by the fencing. No cars will run over my eggs or young and no dogs will run my chicks into exhaustion. My chicks can escape northern harriers, black-backed gulls and other airborne predators by hiding in the tern condos or pvc pipes and because I have fertilized the area so well, the plants may hold the sand through the winter and I may be able to use the area next summer.
Susan B. (Soo) Whiting has been a columnist for the Vineyard Gazette for more than 25 years and is the author of Vineyard Birds and recently published Vineyard Birds II, available at local bookstores. Avian photographer Lanny McDowell is a frequent contributor to the Gazette; his work has been shown in numerous Island galleries and can be viewed at ottgallerymv.com.