Breeding Bird Atlas 2 Species Accounts
Great Blue Heron
- Fairly widespread and strongly increasing
Perhaps no wading bird in Massachusetts is more familiar than the graceful and statuesque Great Blue Heron. This species has very adaptable feeding habits, readily taking fish, amphibians, crustaceans, reptiles, and sometimes even small mammals. Its broad menu has made it a common sight at ponds, rivers, lakes, streams, marshes, estuaries, coastal bays, and meadows across the state in recent years. That hasn’t always been the case, however. A century ago, breeding Great Blue Herons were all but absent from the Commonwealth of Massachusetts.
Historic StatusGifted with beautiful plumage, the Great Blue Heron was a “constant resident in Massachusetts” in the 1830s (Peabody 1839), hardy enough to withstand a New England winter and just as well suited for the more temperate days of summer. By the 1870s, the question was raised as to whether or not Great Blue Herons still nested in Massachusetts. Hunted for its beautiful plumes, the species became known as a common migrant but a “not common summer resident” (Allen, 1878). By the 1920s, Edward Howe Forbush described the species as having “bred not many years ago in Massachusetts” (Forbush 1925). The same year that Forbush's first volume of The Birds of Massachusetts and Other New England States was released in 1925, a Great Blue Heron nesting colony was located in the Harvard Forest in Petersham. The colony survived until it was destroyed by the hurricane of 1938, and no colonies of like size were found in Massachusetts for the next 30 years.
Atlas 1 DistributionWide-ranging Great Blue Herons were spotted in more than 60 blocks during Atlas 1, mostly in the central and western parts of the state. The highest western areas in the Taconic Mountains and Berkshire Highlands had little or no heron activity, but the Lower Berkshire Hills, Vermont Piedmont, and especially Berkshire Transition regions each held blocks supporting a handful of Great Blue Herons. Interestingly, the waterways coursing through the Connecticut River Valley had only 3 occupied blocks and no Confirmations, while the Worcester Plateau accounted for a quarter of all Atlas 1 records for the species. The Lower Worcester Plateau and Coastal Plains together contributed 22 out of 64 blocks, but the only region east of the Coastal Plains to report breeding Great Blue Herons was the Bristol/Narragansett Lowlands (3 blocks).
Atlas 2 Distribution and ChangeWith plume hunters no longer a threat, Great Blue Herons have returned to Massachusetts. Aided by the early-twentieth-century reintroduction of the beaver, Great Blues took to the newly created wetlands for which that toothy mammal is so well known with aplomb. The numbers alone reflect this situation: from 7% block occupancy in Atlas 1 to 46% in just 35 years. When looking at the blocks with the best survey data, every ecoregion in the state except the Vermont Piedmont underwent increases in the presence of this species, and the Vermont Piedmont maintained an even pace. To further illustrate the species’ growth, consider these facts: in the Berkshire Highlands, Great Blue Herons were found in 22 blocks where they were not detected in Atlas 1. In the Bristol/Narragansett Lowlands, they were found in 46 new blocks, and on the Coastal Plains, they were located in 140 new blocks. Great Blue Herons are back!
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||2||5.1||3.1||23||59.0||4.8||21||53.8|
|Lower Berkshire Hills||4||14.3||6.3||14||45.2||2.9||10||37.0|
|Connecticut River Valley||3||5.4||4.7||21||32.3||4.4||13||27.1|
|Lower Worcester Plateau||10||13.5||15.6||55||68.8||11.5||30||55.6|
|S. New England Coastal Plains and Hills||12||4.4||18.8||176||62.2||36.7||137||60.6|
|Bristol and Narragansett Lowlands||3||2.8||4.7||48||42.1||10.0||45||44.6|
|Cape Cod and Islands||0||0.0||0.0||16||11.1||3.3||15||12.5|