THE GOPHER TORTOISE:THE GOPHER TORTOISE:A SPECIES IN DECLINEA SPECIES IN DECLINE

“working to conserve the gopher tortoise and the fascinating world in which it lives”

A presentation by the Gopher Tortoise Council modified by Nora Demers for the Nature Place, City of

Bonita Springs onMay 11, 2009

This program was partially funded with grants from the Georgia Department of Natural Resources and the League of Environmental Educators in Florida

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

The Gopher TortoiseThe Gopher Tortoise((Gopherus polyphemusGopherus polyphemus))

Gopherus polyphemusGopherus polyphemus

Chordata- spinal cord and bony Chordata- spinal cord and bony vertebrae vertebrae

Reptilia- scales, amniotic eggs, Reptilia- scales, amniotic eggs, ectothermicectothermic

Testudines- flattened fused bones, ribs Testudines- flattened fused bones, ribs and vertebraeand vertebrae

Testidinoidea- clawed elephantine hind Testidinoidea- clawed elephantine hind feet, no webbingfeet, no webbing

Gopherus- burrowerGopherus- burrower Polyphemus- lives in cave (Greek)Polyphemus- lives in cave (Greek)

EvolutionEvolution

Tortoiselike fossils found from early Tortoiselike fossils found from early Triassic (250 mya)Triassic (250 mya)

originating in North America over 60 originating in North America over 60 million years agomillion years ago

Gophers first seen during Pleistocene Gophers first seen during Pleistocene (500,000 to 2 mya)(500,000 to 2 mya)

Only land turtle remaining in SE USOnly land turtle remaining in SE US (also only burrowing tortoise – is there a (also only burrowing tortoise – is there a

relationship?)relationship?)

Geographic Range of theGeographic Range of theGopher TortoiseGopher Tortoise

Legal StatusLegal Status AlabamaAlabama- state listed as - state listed as ProtectedProtected; federally listed ; federally listed

as as ThreatenedThreatened west of the Tombigbee and Mobile west of the Tombigbee and Mobile Rivers.Rivers.

FloridaFlorida- state listed as - state listed as ThreatenedThreatened (“harm” enters (“harm” enters protection terminology) protection terminology)

GeorgiaGeorgia- state listed as - state listed as ThreatenedThreatened..

LouisianaLouisiana- state and federally listed as - state and federally listed as ThreatenedThreatened..

MississippiMississippi- state listed as - state listed as EndangeredEndangered; federally ; federally listed as listed as ThreatenedThreatened..

South CarolinaSouth Carolina- state listed as - state listed as EndangeredEndangered..

Longleaf Pine SandhillLongleaf Pine Sandhill

ScrubScrub

Pine FlatwoodsPine Flatwoods

Coastal DunesCoastal Dunes

Disturbed SitesDisturbed Sites

The Ecological Role of FireThe Ecological Role of Fire

Regeneration after fire(tender vittles)

Promotes diversity

Cycles nutrients

Alleviates risk of wildfire

Keystone And Indicator SpeciesKeystone And Indicator Species

Gopher tortoises are keystone species. Gopher tortoises are keystone species. They alter the habitat by constructing and They alter the habitat by constructing and maintaining their burrows, which have over maintaining their burrows, which have over 350 commensals and associates. 350 commensals and associates.

Tortoises are also considered “indicator” Tortoises are also considered “indicator” species, used as an indicator of ecosystem species, used as an indicator of ecosystem health.health.

The Gopher Tortoise BurrowThe Gopher Tortoise Burrow

Burrow detailsBurrow details

Protect from temperature extremes and Protect from temperature extremes and predatorspredators

One openingOne opening Max. length 13 m (40 feet), depth 3m (10’)Max. length 13 m (40 feet), depth 3m (10’) Burrow has ledge at end where tortoise Burrow has ledge at end where tortoise

rests, nice humidityrests, nice humidity In SW Florida burrows are usually shorter In SW Florida burrows are usually shorter

and shallower (water table primary and shallower (water table primary influence)influence)

Adaptations for BurrowingAdaptations for Burrowing

Forefoot

Hind foot

Burrow AssociatesBurrow Associates

Gopher FrogGopher Frog((Rana capitoRana capito))

Spend most of their time in burrows, -species of special concern in FL

Eastern Diamondback RattlesnakeEastern Diamondback Rattlesnake((Crotalus adamanteusCrotalus adamanteus))

CAREFUL- there can be venomous snakes in those burrows!

Eastern Indigo SnakeEastern Indigo Snake((Drymarchon corais couperiDrymarchon corais couperi))

Largest (indigenous) snake in N.A. -glassy black with red head and chin

Federally protected threatened species

Florida MouseFlorida Mouse((Podomys floridanaPodomys floridana))

Occurs only in peninsular Fl. -Excavates side tunnels

Species of special concern in Fl.

Life History of theLife History of theGopher TortoiseGopher 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

Growth in Gopher TortoisesGrowth in Gopher Tortoises

Each annuli represents about 1 yearRates vary by location and environmental conditions

Sexual DimorphismSexual Dimorphismin Gopher Tortoisesin Gopher Tortoises

Female- slightly larger

Male- concave lower plastronthick gular projection

CourtshipCourtship

Typically breed April to JuneLots of head bobbing and nose rubbing

NestingNesting

Lay eggs May to June in apron or sunny sand nearbySingle 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)

Sex DeterminationSex Determination

The incubation temperature of the nest The incubation temperature of the nest determines sexdetermines sex

If over 30 degrees Celsius, female (80 If over 30 degrees Celsius, female (80 degrees F); if under 30 degrees, male.degrees F); if under 30 degrees, male.

Difficult to determine sex of juveniles and Difficult to determine sex of juveniles and sub-adultssub-adults

Males apparently mature sooner than Males apparently mature sooner than femalesfemales

Nest PredationNest Predation

A female may produce a successful nest no more than every 10 years

Nest PredationNest Predation

Also foxes, skunks, fire ants

Hatchling Gopher TortoisesHatchling 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

Hatchling predatorsHatchling predators

Domestic dogs, Fire ants, ‘coons, snakes, hawks

Food PlantsFood Plants

Stinging nettle

Wiregrass

Prickly pear cactus

Home Range SizeHome Range Size

Range depends on habitat Range depends on habitat usually stay near a burrow usually stay near a burrow Adult Females: Adult Females: 0.2 – 1.4 ac (0.1 – 0.6 ha) 0.2 – 1.4 ac (0.1 – 0.6 ha) (house lot size)(house lot size) Adult Males: Adult Males: 1.1 – 3.2 ac (0.4 – 1.3 ha)1.1 – 3.2 ac (0.4 – 1.3 ha) Juveniles (<4 yrs): Juveniles (<4 yrs): 0.02 – 0.9 ac (0.01 – 0.4 ha)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 Most have more than one burrow to call home- structure of burrow unique (left or

right turn)right turn)

Why Gopher Tortoise Why Gopher Tortoise Populations are in Decline:Populations are in Decline:

Problems and a Few SolutionsProblems and a Few Solutions

Races

Food “Hoover Chickens”

(GTC helped end legal harvest in 1988)

Mechanical tortoises in San Antonio Fl.

Upper RespiratoryUpper RespiratoryTract Disease (URTD)Tract Disease (URTD)

Caused by mycoplasm (obligate Caused by mycoplasm (obligate intracellular pathogen like t.b.)intracellular pathogen like t.b.)

Transmission by nose rubbing etcTransmission by nose rubbing etc SymptomsSymptoms

• Clear or white Clear or white

nasal dischargenasal discharge• Watery eyesWatery eyes• Swollen eyelidsSwollen eyelids

The Danger: Asymptomatic The Danger: Asymptomatic TortoisesTortoises

Or is it a danger? Regulations for testing under review

Habitat LossHabitat LossForestry Practices

Mining Agriculture

Development

Habitat lossHabitat loss Housing & other developments Housing & other developments Citrus groves give way to development in Estero (NDN 3/6/06)Citrus groves give way to development in Estero (NDN 3/6/06)

Photo by M Forter Daily News

Invasive SpeciesInvasive Species

Gopher Tortoises and RoadsGopher Tortoises and Roads

Direct effects: • habitat loss• mortality

Indirect effects:• habitat fragmentation• artificial habitat

Roads and Parking lotsRoads and Parking lots

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

Habitat DegradationHabitat Degradation

Mitigation Options in FloridaMitigation Options in Florida

Avoid impacting burrowsAvoid impacting burrows

Set aside on-site preserves/on-site Set aside on-site preserves/on-site relocationrelocation

Relocate tortoises off-siteRelocate tortoises off-site

Incidental Take/ Mitigation BankingIncidental Take/ Mitigation Banking

• Protect (and manage) habitat off-siteProtect (and manage) habitat off-site

Gopher Tortoise RelocationGopher Tortoise Relocation THE GOODTHE GOOD

• Saves individualsSaves individuals• RestockingRestocking• Increased knowledge of tortoise movementsIncreased knowledge of tortoise movements

Gopher Tortoise RelocationGopher Tortoise Relocation

THE BAD… AND THE UGLYTHE BAD… AND THE UGLY• Net loss of habitatNet loss of habitat• Tortoises often leave relocation siteTortoises often leave relocation site• Disruption of resident populationsDisruption of resident populations• Labor intensive/costlyLabor intensive/costly• Transmission of diseaseTransmission of disease• Diverts conservation fundsDiverts conservation funds

The FutureThe Future

Current ResearchCurrent Research

Upper Respiratory Tract Disease- distribution and Upper Respiratory Tract Disease- distribution and impacts- now believed to have co-evolved with tortoisesimpacts- now believed to have co-evolved with tortoises

Investigations into impacts of fire ants on gopher Investigations into impacts of fire ants on gopher tortoise populations in Federally threatened part of tortoise populations in Federally threatened part of rangerange

Studies of other upland species: southern hognose snake; Studies of other upland species: southern hognose snake; eastern indigo snake; red-cockaded woodpeckereastern indigo snake; red-cockaded woodpecker

Summer of ’04 first low frequency sound Summer of ’04 first low frequency sound communications (Eliz. von Miggenthaler- Prez. of Fauna communications (Eliz. von Miggenthaler- Prez. of Fauna Communication Society)Communication Society)

Land Management:Land Management:the Use of Prescribed Firethe Use of Prescribed Fire

Creative Conservation at WorkCreative Conservation at Work

The Nature Conservancy- habitat The Nature Conservancy- habitat acquisition and land stewardshipacquisition and land stewardship

Mitigation BankingMitigation Banking

County-wide land conservation measuresCounty-wide land conservation measures

Gopher Tortoise Conservation InitiativeGopher Tortoise Conservation Initiative

Tortoise Reserve ProgramTortoise Reserve Program

Local Mitigation optionsLocal Mitigation options

Lee County Lee County – Hickey’s Creek Mitigation Park--NOT a Hickey’s Creek Mitigation Park--NOT a

relocation centerrelocation center– Persimmon Ridge, Caloosahatchee Regional Persimmon Ridge, Caloosahatchee Regional

Park, 10-mile Canal Park relocation for private Park, 10-mile Canal Park relocation for private (developers) mitigation(developers) mitigation

– Gator Hole -20/20 lands (off Corkscrew Rd.) Gator Hole -20/20 lands (off Corkscrew Rd.) for public improvement (3-oaks expansion)for public improvement (3-oaks expansion)

Collier County- Maureen Bonness good Collier County- Maureen Bonness good contactcontact

What You Can DoWhat You Can Do

Landscape with native plant species (many are Landscape with native plant species (many are food plants of gopher tortoises)food plants of gopher tortoises)

Become active in conservation organizations Become active in conservation organizations that promote habitat protection and that promote habitat protection and managementmanagement

Be a watch dog for tortoisesBe a watch dog for tortoises

Write to your local politicians about issues that Write to your local politicians about issues that affect tortoises and their habitataffect tortoises and their habitat

Vote!Vote!

Listing in FloridaListing in Florida

FWC Draft Biological Status Report (Nov. ’05)FWC Draft Biological Status Report (Nov. ’05)Criteria for State Listing (Rule 68A-1.00 F.A.C.)Criteria for State Listing (Rule 68A-1.00 F.A.C.)

Population size reduction due to habitat loss –note that Population size reduction due to habitat loss –note that human population has increased 2,161% since 1910 human population has increased 2,161% since 1910 (2003 figure) and has been doubling every 20 years (2003 figure) and has been doubling every 20 years during the 1990’sduring the 1990’s

- pre-European settlement estimate of habitat: 10 pre-European settlement estimate of habitat: 10 million acres, today: 1.7 million acremillion acres, today: 1.7 million acre

Meets criteria for classification as Threatened Meets criteria for classification as Threatened

FWC requesting inputFWC requesting input

What to do if You Find aWhat to do if You Find a Stray Tortoise Stray Tortoise

On roads, move tortoise to nearest On roads, move tortoise to nearest habitat (preferably in direction it was habitat (preferably in direction it was heading) - BEWARE OF TRAFFIC!heading) - BEWARE OF TRAFFIC!

If injured, contact your local Game If injured, contact your local Game Commission or Department of Natural Commission or Department of Natural ResourcesResources

“Hands off” unless:

The Mission of the Gopher The Mission of the Gopher Tortoise CouncilTortoise Council

EducationEducation

Habitat protectionHabitat protection

ResearchResearch

For More Information:For More Information:

Write to us at the following address:Write to us at the following address:

Gopher Tortoise CouncilGopher Tortoise Council

c/o Florida Museum of Natural Historyc/o Florida Museum of Natural History

P.O. Box 117800P.O. Box 117800

University of FloridaUniversity of Florida

Gainesville, FL 32611-7800Gainesville, FL 32611-7800

Visit our web site:Visit our web site:

www.gophertortoisecouncil.orgwww.gophertortoisecouncil.org

Now a short quiz-Now a short quiz-

Can you find Can you find the tortoise?the tortoise?

images courtesy of Jill Kusbaimages courtesy of Jill Kusba

How big is this tortoise?How big is this tortoise?

HINT: It is a one-year HINT: It is a one-year old hatchlingold hatchling

Can you find the burrow?Can you find the burrow?

The FutureThe Future