Breeding Bird Atlas 2 Species Accounts
- Local and likely increasing
- Action/monitoring needed
- Species of Special Concern
The appropriately named Least Tern is the smallest of the tern species that breed in Massachusetts, but that in no way has stopped it from becoming big news. Its preference for nesting on sandy mainland beaches rather than the islands favored by many terns has brought the species into conflict with humanity time and time again. Currently sharing top conservation billing and some prime beach real estate with the Piping Plover, this listed Species of Special Concern is doing its best to hold on.
Historic StatusAlexander Wilson called the Least Tern the Lesser Tern, and the early ornithologists of Massachusetts knew it as the Silvery Tern, but by any name the Least Tern was a ”not uncommon” summer resident and breeder along the state coastline in the early and mid-1800s. Joel Asaph Allen called it, “Common along the coast in summer” in 1878, but when gunners employed by the millinery trade moved in the Least Tern suffered. The species gave up historic breeding grounds at Ipswich and other places, gradually retreating to a few, more southerly haunts. Edward Howe Forbush estimated that 300 birds remained in the breeding colonies on the Cape and Islands, on the South Shore, and South Coast, but by the 1930s Massachusetts State Ornithologist Joseph “Archie” Hagar estimated almost three times that many. Under full legal protection, the population in Massachusetts increased throughout the middle decades of the twentieth century.
Atlas 1 DistributionBy the time of Atlas 1, the recovering Least Tern population was still not free of its conflicts with humans. The Least Tern’s preference for the same sandy beaches valued by humans for recreation has always created a rocky relationship between the terns and humans in many areas. However, it has not been a problem at protected sites like the Parker River National Wildlife Refuge on Plum Island in the Coastal Plains, where Least Terns nested in several adjacent blocks. The Boston Basin had a single, somewhat surprising block in the heart of Boston Harbor, and the Bristol/Narragansett Lowlands also hosted breeding Least Terns around the southwestern coast. Cape Cod and the Islands were unquestionably the places favored by Least Terns, accounting for 43 of 54 occupied blocks, many of which were located on popular tourist beaches.
Atlas 2 Distribution and ChangeLeast Tern block occupancy jumped to 89 blocks during Atlas 2. The species’ persistence was remarkable – they were found in a total of 50 blocks during Atlas 1 and persisted in at least 50 of those blocks during Atlas 2. With new additional blocks, and very few losses, Least Terns have seemingly gained ground. More precise estimates of the change in this species’ breeding status (see Note below) support an increasing abundance in the state, although there is considerable variability in this population.
Atlas 1 Map
Atlas 2 Map
Atlas Change Map
|Atlas 1||Atlas 2||Change|
|Ecoregion||# Blocks||% Blocks||% of Range||# Blocks||% Blocks||% of Range||Change in # Blocks||Change in % Blocks|
|Marble Valleys/Housatonic Valley||0||0.0||0.0||0||0.0||0.0||0||0.0|
|Lower Berkshire Hills||0||0.0||0.0||0||0.0||0.0||0||0.0|
|Connecticut River Valley||0||0.0||0.0||0||0.0||0.0||0||0.0|
|Lower Worcester Plateau||0||0.0||0.0||0||0.0||0.0||0||0.0|
|S. New England Coastal Plains and Hills||7||2.6||12.7||15||5.3||16.9||6||2.7|
|Bristol and Narragansett Lowlands||4||3.8||7.3||8||7.0||9.0||2||2.0|
|Cape Cod and Islands||43||31.6||78.2||61||42.4||68.5||14||11.7|