Breeding Bird Atlas 2 Species Accounts
- Very local, trend not established
A common denizen of wetlands in the southern part of the country, the Tricolored Heron is one of three species in the genus Egretta that breeds in Massachusetts. Of the three, it is also the most recent to become a breeder in the state and, correspondingly, the least abundant. Massachusetts is on the very northern fringe of its breeding range.
Historic StatusThe Tricolored, formerly known as the Louisiana Heron, first appeared in Massachusetts with a visit to Ipswich in 1940. That event took place at the dawn of a three-decade-long northern expansion of the East Coast population, as the birds eventually appeared as far north as Maine. From 1960 onward, Tricolored Herons occurred annually in the Bay State. By the early 1970s, suspicions of breeding began to arise since the species was seen regularly heading for an evening roost on Clark’s Island in Duxbury Bay along with other herons and egrets. A search, however, failed to turn up any breeding evidence (Petersen & Meservey 2003).
Atlas 1 DistributionNot surprisingly, breeding Tricolored Herons barely registered a blip on the proverbial radar during Atlas 1. The only locality where nesting occurred during the Atlas period was at the House Island heronry just off the coast of Manchester in Essex County. Since then, at least three pairs of Tricolored Herons are known to have nested there, but despite occasional sightings no substantial evidence of breeding was recorded anywhere else in the state during Atlas 1.
Atlas 2 Distribution and ChangeBy the time of Atlas 2, Tricolored Herons had given up their residence at House Island, but they found a new one on Tuckernuck Island off Nantucket. At the extreme northern end of its range, the Tricolored Heron might best be considered a tale of extralimital adventure by pioneers in regard to its nesting status in Massachusetts. With the climate changing, who knows what we might expect from this species in the future?
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||1||0.4||100.0||0||0.0||0.0||-1||-0.4|
|Bristol and Narragansett Lowlands||0||0.0||0.0||0||0.0||0.0||0||0.0|
|Cape Cod and Islands||0||0.0||0.0||1||0.7||100.0||1||0.8|