Status in New England


Origin categories, as defined by Mass Nature are as follows:

  • Native to New England. When this single word alone is applied to birds, it generally indicates that at least some individuals breed in New England and at least some individuals overwinter in New England.
  • Native (Breeding): Used for birds or other taxa that breed in New England but overwinter outside of New England.
  • Native (Nonbreeding/Overwintering): Used for birds or other taxa that overwinter in New England but breed outside of New England.
  • Native Migrant: Used for birds or other taxa that migrate through New England but do not breed or overwinter there.
  • Introduced (intentionally or unintentionally) to New England by people. (Note: a plant taxon may be native to one part of New England but introduced to another part of New England. Some populations or subspecies of organisms may be native to New England while others of the same species are non-native. If the word “introduced” is used alone it indicates that the taxon (including all its populations, subspecies, etc.) is not native to any part of New England).
  • Recent: Used for birds or other taxa that have recently (during the colonial period or more recently) moved into New England by natural means (without being directly introduced by people; although changes in the environment caused by people may have been a factor in the species expansion or movement into New England).
  • Recent (Breeding): Used for birds or other taxa that may have been previously only non-breeding/overwintering in New England but in recent times at least some have begun breeding in New England.
  • Introduced Subspecies: Used for plants. Are subspecies that are not native to New England. This term is used instead of “Introduced” when a species has one or more subspecies that are native to New England and one or more subspecies that are not native to New England.
  • Extirpated: Indicates a species that was native to New England, but was entirely eliminated from New England. For example, mountain lions and wolves were entirely eliminated from New England as a result of hunting.
  • Extirpated (Breeding): Used for birds. Indicates that breeding populations were extirpated from New England (but nonbreeding individuals may have still been observed in New England).
  • Reintroduced: Species was released back into the area where it formerly lived. For example, Wild Turkeys from New York were released in New England to replace populations that had been extirpated.

Note, in some cases a combination of factors may apply.

Example 1: The origin for the plant Prunella vulgaris is described as “Native, Introduced Subspecies” because there is a native subspecies in New England and a subspecies that is introduced (non-native) to New England.

Example 2: The origin for the plant Aristida basiramea is described as “Native, Introduced” because the species is native to part of New England but has been introduced to other parts of New England (where it did not originally occur).

Example 3: The origin for the Mallard (Anas platyrhynchos) is described as “Native (Nonbreeding/Overwintering), Introduced, Recent (Breeding)” because it was originally an uncommon nonbreeding visitor to New England. Later it was introduced to New England for hunting purposes, and the introduced population became permanent residents. More recently naturally occurring populations of Mallards from the Midwest expanded their range eastward, into New England.

Sources of Origin Data

Invasive, Pest or Pathogen

This section indicates whether the particular species is considered invasive, potentially invasive, or a pest or pathogen in New England. If so, it provides sources for these classifications. The sources are listed below.

For Invasive Plants (terrestrial or aquatic)

For Other Terrestrial Invasive Species, Pests or Pathogens

For Marine and Aquatic Invasive Species

Rarity Designations

Information on rarity is provided for any taxon considered by state or federal government to be rare or potentially rare or vulnerable in New England. This information includes the source (e.g., Massachusetts Endangered Species Act List), location for which the taxon is considered rare (e.g. within the Commonwealth of Massachusetts), and the rarity designation (e.g., Threatened).

Most taxa listed as rare within a state have two rarity descriptions: a state (subnational) rank (e.g., S1, S2, S3) and a state listing (e.g., Endangered, Threatened). Mass Nature provides the state listing designation if available. If there is no state listing designation, then Mass Nature provides the taxon’s state/subnational rank. You should refer to a state’s rare species list and associated regulations for definitions for rarity designations. Also, you should always check the original source (state or federal rarity listing) to make sure that the rarity designation you obtained from Mass Nature is accurate and up to date.

Although rarity categories in rare species lists vary somewhat from state to state, all states use the same conservation status ranks. The state/subnational ranks range from S1 (Critically Imperiled) to S5 (Secure). Some taxa have a status of "Unranked/Not State Ranked", which means their status within the state has not yet been assessed. Species with a status of "Unrankable” cannot currently be ranked due to conflicting or insufficient information. A rank of “Not Applicable” is used for species that are not considered to be suitable targets for conservation efforts. A full list of status ranks and their definitions may be found on the NatureServe Explorer website:

Rarity designations were obtained from the following sources:

State Lists of Rare Species

Federally Listed Species

  • U.S. Fish & Wildlife Service. Endangered Species website. This website allows you to obtain lists of species protected under the Endangered Species Act that occur within a given state or look up the status of a given species. Website: Accessed July 1, 2017.

State Wildlife Action Plans

Note: These are abbreviated WAP (Wildlife Action Plan) or SWAP (State Wildlife Action Plan). The plans identify and provide guidance for the management and protection of Species of Greatest Conservation Need (SGCN) (also abbreviated GCN for Greatest Conservation Need).


DeGraaf, R.M. and M. Yamasaki. 2001. New England Wildlife. Habitat, Natural History, and Distribution. University Press of New England, Hanover, NH. 482 pages.

Last edited: 13 Sept. 2017