Lobster and Fishes               Clamming and Oystering               Piping Plovers               Raptors              Forest Birds

State-Listed Species

The Connecticut Endangered Species Act, passed in 1989, recognizes the importance of our state’s plant and animal populations and the need to protect them from threats that could lead to their extinction. The overall goal is to conserve, protect, restore and enhance any endangered or threatened species and their essential habitat.

As detailed in the graph above, the total number of state-listed species has increased from 599 in 2005 to 624 in 2015, an increase of approximately 4.1 percent. The listing of species as endangered, threatened, and special concern, according to their level of risk and their status, should be reviewed every five years. However, there has been no update to the state-listed species list since 2015. The current list of state-listed species is as follows:

 Taxonomic Group  Endangered  Special Concern   Threatened   Grand Total
Amphibians 2
4 2 8
Birds  18 20 12 50
Fish 5 8   13
Invertebrates 33 117 44 194
Mammals 6 8   14
Plants 133 152 46  331


7 14
Grand Total 201  316  107  624

The Department of Energy and Environmental Protection (DEEP) uses Natural Diversity Data Base (NDDB) maps as a pre-screening tool to help identify potential impacts to state-listed species. These data are also used by groups wishing to identify areas of potential conservation concern. The NDDB maps, which are updated periodically (every 6 months or so), represent approximate locations of endangered, threatened, and special concern species and significant natural communities in Connecticut.

In 2005 and again in 2015, Connecticut developed Wildlife Action Plans* to identify the species of greatest conservation need (GCN), their key habitats, problems, research needs, and conservation actions.52  The Wildlife Action Plan for Connecticut is due to be updated by 2025.

Technical Note: *Formerly known as the Comprehensive Wildlife Conservation Strategy.

Resident Turtles

Quick Summary - dash x x

Five of the eight turtle species that live in Connecticut year-round are listed as endangered, threatened, or of special concern.

turtleTurtles are excellent indicators of ecological health. This indicator includes the eight species of turtle that live in Connecticut (but not the four marine species that visit Long Island Sound in summer, all of which are threatened or endangered). In 2015, five of the eight resident turtle species were listed as endangered or of special concern: bog turtle (endangered), eastern box turtle, wood turtle northern, diamondback terrapin, and spotted turtle (species of special concern). The ability for turtles to sustain a stable population will be difficult because turtles take a long time to reach sexual maturity and have low survivorship when newly hatched.


Goal: The goal for all endangered and threatened species is for recovery of their populations to a stable, sustainable level.



Quick Summary - x x x


Eight of the nine bat species are on the latest list of species that are endangered, threatened, or of special concern.

batBat populations in Connecticut have experienced a catastrophic decline that led to the classification in 2015 of three more bat species as endangered in Connecticut and has raised concerns about the future of bats in the state. This decline in bat population, between 2007 and 2010, is primarily due to an epidemic fungal disease called white-nose syndrome (WNS). The chart depicts data for the winter population of three cave-dwelling bat species at a sentinel hibernation site monitored annually by the Department of Energy and Environmental Protection (DEEP).53  This sentinel cave is one of Connecticut’s best remaining overwintering site for cave bats. Recovery, if one occurs, will be slow: adult female bats usually produce just one pup per year. Bats eat insects, including mosquitoes, a number of which may carry diseases that affect humans, birds, horses and other animals.


Goal: The goal for bats is for recovery of all nine species to a stable, sustainable population.

Technical Note: The horizontal axis for bats displays every other year between 1999 and 2007.


52 DEEP, 2015 Connecticut Wildlife Action Plan portal.ct.gov/-/media/DEEP/wildlife/pdf_files/nongame/CTWAP/CTWAPExecutiveSummarypdf.pdf
53 DEEP, Wildlife Division, Wildlife Diversity Program, and State and Tribal Wildlife Grants programs; personal communication from Brian Hess, February 17, 2021.