This page of "introduced species" covers several different types of introductions.  There are three main distinctions that people should be aware of when looking at introduced species in this region:

1. Some "introduced species" never historically occurred in our region, like the Italian Wall Lizard.  When these individuals are released they are truly "invading" an area that they never historically inhabited.

2. Other "introduced species" like the wood turtle, may have occurred in our area historically but are now extinct throughout the region.  Scattered individuals may be frequently released by people who find them in neighboring regions (upstate NY, northern NJ) where they still occur naturally. This may happen during a vacation or wilderness trip.  When the person or persons return home to the Long Island, Staten Island and Manhattan area they may release the captured animals where they are now extinct.

3. Some of our "introduced" reptiles and amphibians are so similar to our normal native species that they are called subspecies.  The term subspecies refers to animals that are identical in their genus and species status, yet have evolved slight differences due geographic isolation, climatic differences or other environmental factors.  Although different subspecies can interbreed in captivity, they are usually isolated from each other in the wild and do not interbreed.  Subspecies differences may be minute or may be easily observable.  The diamondback terrapin for example has seven subspecies that are found along the Atlantic and Gulf coasts. The native New York subspecies is the Northern diamondback terrapin, Malaclemys terrapin terrapin.  Yet the other six subspecies are sometimes released in the NY.  The danger of subspecies mixing is that individuals can interbreed when mixed, while they would normally never meet in the wild.  This can lead to genetic mixing and destruction of biodiversity.

As you read each individual species description you can learn for yourself which of the following situations occurred for each of the region's introductions.
 

23a. Painted Turtle - Chrysemys picta ssp.⁷
27.   Red Eared Slider - Trachemys scripta elegans⁷
28.   Redbelly Turtle - Pseudemys rubriventris⁷
29.   Yellowbelly Turtle - Trachemys scripta scripta⁷
51.   Wood Turtle - Clemmys insculpta^{5, 6, 7}
38a. Common Garter Snake - Thamnophis sirtalis ssp⁷
39a. Ribbon Snake - Thamnophis sauritus ssp.⁷
47.   Italian Wall Lizard - Podarcis sicula⁷
48.   Northern Fence Lizard - Sceloporus undulatus⁷
25.   Diamondback Terrapin - Malaclemys terrapin ssp⁵



1 = Federally Endangered Species
2 = Federally Threatened Species
3 = New York State Endangered Species
4 = New York State Threatened Species
5 = New York State Special Concern Species
6 = Species Extinct in our area
7 = Species Introduced to our area