THE GOPHER TORTOISE:

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THE GOPHER TORTOISE

• A SPECIES IN DECLINE

A presentation by the Gopher Tortoise Council
modified by Nora Demers for the Nature Place,
City of Bonita Springs on May 11, 2009
working to conserve the gopher tortoise and the
fascinating world in which it lives
This program was partially funded with grants
from the Georgia Department of Natural Resources
and the League of Environmental Educators in
Florida
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Acknowledgments

• The following people generously donated
  photographs or slides for this presentation
• Joan D. Berish, C. Kenneth Dodd, Jr., George L.
  Heinrich, Sharon Hermann, Joseph W. Jones
  Ecological Research Center, Lee County Parks
  Recreation, Barry Mansell, Henry Mushinsky, Lora
  L. Smith, Jill Kusba, and Nora Demers
• Developed by Laura Wewerka and Lora L. Smith

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The Gopher Tortoise(Gopherus polyphemus)
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Gopherus polyphemus

• Chordata- spinal cord and bony vertebrae
• Reptilia- scales, amniotic eggs, ectothermic
• Testudines- flattened fused bones, ribs and
  vertebrae
• Testidinoidea- clawed elephantine hind feet, no
  webbing
• Gopherus- burrower
• Polyphemus- lives in cave (Greek)

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Evolution

• Tortoiselike fossils found from early Triassic
  (250 mya)
• originating in North America over 60 million
  years ago
• Gophers first seen during Pleistocene (500,000 to
  2 mya)
• Only land turtle remaining in SE US
• (also only burrowing tortoise is there a
  relationship?)

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Geographic Range of theGopher Tortoise
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Legal Status

• Alabama- state listed as Protected federally
  listed as Threatened west of the Tombigbee and
  Mobile Rivers.
• Florida- state listed as Threatened (harm
  enters protection terminology)
• Georgia- state listed as Threatened.
• Louisiana- state and federally listed as
  Threatened.
• Mississippi- state listed as Endangered
  federally listed as Threatened.
• South Carolina- state listed as Endangered.

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Longleaf Pine Sandhill
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Scrub
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Pine Flatwoods
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Coastal Dunes
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Disturbed Sites
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The Ecological Role of Fire
Promotes diversity Cycles nutrients Alleviates
risk of wildfire
Regeneration after fire (tender vittles)
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Keystone And Indicator Species

• Gopher tortoises are keystone species. They
  alter the habitat by constructing and maintaining
  their burrows, which have over 350 commensals and
  associates.
• Tortoises are also considered indicator
  species, used as an indicator of ecosystem health.

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The Gopher Tortoise Burrow
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Burrow details

• Protect from temperature extremes and predators
• One opening
• Max. length 13 m (40 feet), depth 3m (10)
• Burrow has ledge at end where tortoise rests,
  nice humidity
• In SW Florida burrows are usually shorter and
  shallower (water table primary influence)

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Adaptations for Burrowing
Hind foot
Forefoot
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Burrow Associates
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Gopher Frog (Rana capito)
Spend most of their time in burrows, -species of
special concern in FL
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Eastern Diamondback Rattlesnake(Crotalus
adamanteus)
CAREFUL- there can be venomous snakes in those
burrows!
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Eastern Indigo Snake (Drymarchon corais couperi)
Largest (indigenous) snake in N.A. -glassy black
with red head and chin Federally protected
threatened species
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Florida Mouse(Podomys floridana)
Occurs only in peninsular Fl. -Excavates side
tunnels Species of special concern in Fl.
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Life History of theGopher Tortoise

• Average length 10-12 inches (25-30 cm)
• Average weight 4 kg (9 lbs)
• Females slightly larger than males- sexually
  mature
• when 15-20 years old
• Slow growing
• (depending on environment)
• Can live more than 60 years

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Growth in Gopher Tortoises
Each annuli represents about 1 year Rates vary by
location and environmental conditions
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Sexual Dimorphismin Gopher Tortoises
Male- concave lower plastron thick gular
projection
Female- slightly larger
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Courtship
Typically breed April to June Lots of head
bobbing and nose rubbing
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Nesting
Lay eggs May to June in apron or sunny sand
nearby Single clutch per year (or not at all)
Average 6 eggs, up to 25! Size of ping pong
balls Incubation time 80-110 days (S to Northern
range)
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Sex Determination

• The incubation temperature of the nest determines
  sex
• If over 30 degrees Celsius, female (80 degrees
  F) if under 30 degrees, male.
• Difficult to determine sex of juveniles and
  sub-adults
• Males apparently mature sooner than females

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Nest Predation
A female may produce a successful nest no more
than every 10 years
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Nest Predation
Also foxes, skunks, fire ants
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Hatchling Gopher Tortoises

• Hatchlings are 1-2 inches long (25-30 cm)
• Use adult burrows or excavate their own
• Soft shell renders them
• vulnerable to predators
• for first 7 years

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Hatchling predators
Domestic dogs, Fire ants, coons, snakes, hawks
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Food Plants
Stinging nettle
Prickly pear cactus
Wiregrass
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Home Range Size

• Range depends on habitat
• usually stay near a burrow
• Adult Females
• 0.2 1.4 ac (0.1 0.6 ha)
• (house lot size)
• Adult Males
• 1.1 3.2 ac (0.4 1.3 ha)
• Juveniles (lt4 yrs)
• 0.02 0.9 ac (0.01 0.4 ha)
• Most have more than one burrow to call home-
  structure of burrow unique (left or right turn)

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Why Gopher Tortoise Populations are in
DeclineProblems and a Few Solutions
Races
Mechanical tortoises in San Antonio Fl.
Food Hoover Chickens (GTC helped end legal
harvest in 1988)
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Upper RespiratoryTract Disease (URTD)

• Caused by mycoplasm (obligate intracellular
  pathogen like t.b.)
• Transmission by nose rubbing etc
• Symptoms
• Clear or white
• nasal discharge
• Watery eyes
• Swollen eyelids

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The Danger Asymptomatic Tortoises
Or is it a danger? Regulations for testing under
review
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Habitat Loss
Forestry Practices
Development
Mining
Agriculture
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Habitat loss

• Housing other developments
• Citrus groves give way to development in Estero
  (NDN 3/6/06)

Photo by M Forter Daily News
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Invasive Species
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Gopher Tortoises and Roads

• Direct effects
• habitat loss
• mortality

• Indirect effects
• habitat fragmentation
• artificial habitat

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Roads and Parking lots

• Balance desire of humans to enjoy surroundings
  with needs of native species

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Habitat Degradation
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Mitigation Options in Florida

• Avoid impacting burrows
• Set aside on-site preserves/on-site relocation
• Relocate tortoises off-site
• Incidental Take/ Mitigation Banking
• Protect (and manage) habitat off-site

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Gopher Tortoise Relocation

• THE GOOD
• Saves individuals
• Restocking
• Increased knowledge of tortoise movements

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Gopher Tortoise Relocation

• THE BAD AND THE UGLY
• Net loss of habitat
• Tortoises often leave relocation site
• Disruption of resident populations
• Labor intensive/costly
• Transmission of disease
• Diverts conservation funds

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The Future
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Current Research

• Upper Respiratory Tract Disease- distribution and
  impacts- now believed to have co-evolved with
  tortoises
• Investigations into impacts of fire ants on
  gopher tortoise populations in Federally
  threatened part of range
• Studies of other upland species southern hognose
  snake eastern indigo snake red-cockaded
  woodpecker
• Summer of 04 first low frequency sound
  communications (Eliz. von Miggenthaler- Prez. of
  Fauna Communication Society)

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Land Managementthe Use of Prescribed Fire
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Creative Conservation at Work

• The Nature Conservancy- habitat acquisition and
  land stewardship
• Mitigation Banking
• County-wide land conservation measures
• Gopher Tortoise Conservation Initiative
• Tortoise Reserve Program

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Local Mitigation options

• Lee County
• Hickeys Creek Mitigation Park--NOT a relocation
  center
• Persimmon Ridge, Caloosahatchee Regional Park,
  10-mile Canal Park relocation for private
  (developers) mitigation
• Gator Hole -20/20 lands (off Corkscrew Rd.) for
  public improvement (3-oaks expansion)
• Collier County- Maureen Bonness good contact

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What You Can Do

• Landscape with native plant species (many are
  food plants of gopher tortoises)
• Become active in conservation organizations that
  promote habitat protection and management
• Be a watch dog for tortoises
• Write to your local politicians about issues that
  affect tortoises and their habitat
• Vote!

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Listing in Florida

• FWC Draft Biological Status Report (Nov. 05)
• Criteria for State Listing (Rule 68A-1.00 F.A.C.)
• Population size reduction due to habitat loss
  note that human population has increased 2,161
  since 1910 (2003 figure) and has been doubling
  every 20 years during the 1990s
• pre-European settlement estimate of habitat 10
  million acres, today 1.7 million acre
• Meets criteria for classification as Threatened
• FWC requesting input

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What to do if You Find a Stray Tortoise
Hands off unless

• On roads, move tortoise to nearest habitat
  (preferably in direction it was heading) - BEWARE
  OF TRAFFIC!
• If injured, contact your local Game Commission or
  Department of Natural Resources

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The Mission of the Gopher Tortoise Council

• Education
• Habitat protection
• Research

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For More Information

• Write to us at the following address
• Gopher Tortoise Council
• c/o Florida Museum of Natural History
• P.O. Box 117800
• University of Florida
• Gainesville, FL 32611-7800
• Visit our web site
• www.gophertortoisecouncil.org

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Now a short quiz-

• Can you find the tortoise?

images courtesy of Jill Kusba
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How big is this tortoise?

• HINT It is a one-year old hatchling

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Can you find the burrow?
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The Future