Threatened Species Management System – Listing Recommendations and Criteria

June 2011

Species recommended for listing as threatened (40)

American oystercatcher
Atlantic sturgeon
Barbour's map turtle
Big Cypress fox squirrel
Black Creek crayfish
Black skimmer
Blackmouth shiner
Bluenose shiner
Burrowing owl
Crystal darter
Everglades mink
Florida bog frog
Florida brown snake
Florida Keys mole skink
Florida mastiff bat
Florida pine snake
Florida sandhill crane
Georgia blind salamander
Key ringneck snake
Key silverside

Least tern
Little blue heron
Marian's marsh wren
Pillar coral
Reddish egret
Rim rock crowned snake
Sanibel Island rice rat
Saltmarsh topminnow
Santa Fe cave crayfish
Sherman's short-tailed shrew
Southern tessellated darter
Roseate spoonbill
Scott's seaside sparrow 
Short-tailed snake
Snowy plover
Southeastern American kestrel
Tricolored heron
Wakulla seaside sparrow
White-crowned pigeon
Worthington's marsh wren

Species recommended for removal from the list (16) 

Alligator snapping turtle
Brown pelican
Florida black bear
Florida mouse
Florida tree snail
Gopher frog
Lake Eustis pupfish
Limpkin

Peninsula ribbon snake*
Pine Barrens treefrog
Red rat snake*
Rivulus
Snowy egret
Striped mud turtle*
Suwannee cooter
White ibis

*Keys species only

Species recommended as SSC (5)

Eastern chipmunk
Harlequin darter
Homosassa shrew
Osprey (southern coastal population)
Sherman's fox squirrel

FWC criteria for listing

Listing criteria evaluate risk of extinction through the following biological indicators of populations that are threatened with extinction:

  • Rapidly declining population in past, present or future
  • Restricted geographic range and critical habitat
  • Small population size
  • Model indicating risk of extinction >10 percent in 100 years
  • Fluctuations in population or fragmentation

 Specifically the criteria are:

  1. Population decline of 50 percent or greater in the past where causes of the decline have stopped, OR
    Declines of 30 percent in past, present or future three generations or 10 years, whichever is longer.
  2. Range is less than 7,722 square miles, OR
    The critical habitat (area of occupancy) is less than 772 square miles, AND
    Two of the following:
    • Population severely fragmented
    • Continuing decline in habitat and numbers of populations or mature individuals
    • Extreme fluctuations in habitat, numbers of populations or mature individuals
  3. Population estimated to number fewer than 10,000 mature individuals, AND
    • Either a continuing decline of 10 percent of the population; OR
    • Continuing decline and at least one of
      • small subpopulations (<1,000) or all individuals in one location; OR
      • extreme fluctuations in number of individuals
  4. Population estimated to contain fewer than 1,000 individuals, OR
    Occupies less than 8 square miles
  5. Model showing the probability of extinction is at least 10 percent within 100 years. 

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FWC Facts:
The eastern indigo snake is the longest snake in the United States. Adults can reach 6 to 8 1/2 feet in length.

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