THE GOPHER TORTOISE:

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THE GOPHER TORTOISE:. A presentation by the Gopher Tortoise Council modified by Nora Demers for the Nature Place, City of Bonita Springs on May 11, 2009. A SPECIES IN DECLINE. “working to conserve the gopher tortoise and the fascinating world in which it lives”. - PowerPoint PPT Presentation

Text of THE GOPHER TORTOISE:

  • THE GOPHER TORTOISE:A SPECIES IN DECLINEworking to conserve the gopher tortoise and the fascinating world in which it livesA 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

  • AcknowledgmentsThe 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

  • The Gopher Tortoise(Gopherus polyphemus)

  • Gopherus polyphemusChordata- spinal cord and bony vertebrae Reptilia- scales, amniotic eggs, ectothermicTestudines- flattened fused bones, ribs and vertebraeTestidinoidea- clawed elephantine hind feet, no webbingGopherus- burrowerPolyphemus- lives in cave (Greek)

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

  • Geographic Range of theGopher Tortoise

  • Legal StatusAlabama- 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.

  • Longleaf Pine Sandhill

  • Scrub

  • Pine Flatwoods

  • Coastal Dunes

  • Disturbed Sites

  • The Ecological Role of FireRegeneration after fire(tender vittles)Promotes diversity

    Cycles nutrients

    Alleviates risk of wildfire

  • Keystone And Indicator SpeciesGopher 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.

  • The Gopher Tortoise Burrow

  • Burrow detailsProtect from temperature extremes and predatorsOne openingMax. length 13 m (40 feet), depth 3m (10)Burrow has ledge at end where tortoise rests, nice humidityIn SW Florida burrows are usually shorter and shallower (water table primary influence)

  • Adaptations for BurrowingForefootHind foot

  • Burrow Associates

  • Gopher Frog(Rana capito)Spend most of their time in burrows, -species of special concern in FL

  • Eastern Diamondback Rattlesnake(Crotalus adamanteus)CAREFUL- there can be venomous snakes in those burrows!

  • Eastern Indigo Snake(Drymarchon corais couperi)Largest (indigenous) snake in N.A. -glassy black with red head and chinFederally protected threatened species

  • Florida Mouse(Podomys floridana)Occurs only in peninsular Fl. -Excavates side tunnelsSpecies of special concern in Fl.

  • 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

  • Growth in Gopher TortoisesEach annuli represents about 1 yearRates vary by location and environmental conditions

  • Sexual Dimorphismin Gopher TortoisesFemale- slightly largerMale- concave lower plastronthick gular projection

  • CourtshipTypically breed April to JuneLots of head bobbing and nose rubbing

  • NestingLay 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 ballsIncubation time 80-110 days(S to Northern range)

  • Sex DeterminationThe incubation temperature of the nest determines sexIf over 30 degrees Celsius, female (80 degrees F); if under 30 degrees, male.Difficult to determine sex of juveniles and sub-adultsMales apparently mature sooner than females

  • Nest PredationA female may produce a successful nest no more than every 10 years

  • Nest PredationAlso foxes, skunks, fire ants

  • 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

  • Hatchling predatorsDomestic dogs, Fire ants, coons, snakes, hawks

  • Food PlantsStinging nettleWiregrassPrickly pear cactus

  • Home Range SizeRange 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 (
  • Why Gopher Tortoise Populations are in Decline:Problems and a Few SolutionsRacesFood Hoover Chickens(GTC helped end legal harvest in 1988)

    Mechanical tortoises in San Antonio Fl.

  • Upper RespiratoryTract Disease (URTD)Caused by mycoplasm (obligate intracellular pathogen like t.b.)Transmission by nose rubbing etcSymptomsClear or white nasal dischargeWatery eyesSwollen eyelids

  • The Danger: Asymptomatic TortoisesOr is it a danger? Regulations for testing under review

  • Habitat LossForestry PracticesMiningAgricultureDevelopment

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

    Photo by M Forter Daily News

  • Invasive Species

  • Gopher Tortoises and Roads Direct effects: habitat loss mortality Indirect effects: habitat fragmentation artificial habitat

  • Roads and Parking lotsBalance desire of humans to enjoy surroundings with needs of native species

  • Habitat Degradation

  • Mitigation Options in FloridaAvoid impacting burrowsSet aside on-site preserves/on-site relocationRelocate tortoises off-siteIncidental Take/ Mitigation BankingProtect (and manage) habitat off-site

  • Gopher Tortoise RelocationTHE GOODSaves individualsRestockingIncreased knowledge of tortoise movements

  • Gopher Tortoise RelocationTHE BAD AND THE UGLYNet loss of habitatTortoises often leave relocation siteDisruption of resident populationsLabor intensive/costlyTransmission of diseaseDiverts conservation funds

  • The Future

  • Current ResearchUpper Respiratory Tract Disease- distribution and impacts- now believed to have co-evolved with tortoisesInvestigations into impacts of fire ants on gopher tortoise populations in Federally threatened part of rangeStudies of other upland species: southern hognose snake; eastern indigo snake; red-cockaded woodpeckerSummer of 04 first low frequency sound communications (Eliz. von Miggenthaler- Prez. of Fauna Communication Society)

  • Land Management:the Use of Prescribed Fire

  • Creative Conservation at WorkThe Nature Conservancy- habitat acquisition and land stewardshipMitigation BankingCounty-wide land conservation measuresGopher Tortoise Conservation InitiativeTortoise Reserve Program

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

  • What You Can DoLandscape with native plant species (many are food plants of gopher tortoises)Become active in conservation organizations that promote habitat protection and managementBe a watch dog for tortoisesWrite to your local politicians about issues that affect tortoises and their habitatVote!

  • Listing in FloridaFWC 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 1990spre-European settlement estimate of habitat: 10 million acres, today: 1.7 million acreMeets criteria for classification as Threatened FWC requesting input

  • What to do if You Find a Stray TortoiseOn 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

    Hands off unless:

  • The Mission of the Gopher Tortoise CouncilEducation

    Habitat protection

    Research

  • For More Information:Write to us at the following address:Gopher Tortoise Councilc/o Florida Museum of Natural HistoryP.O. Box 117800University of FloridaGainesville, FL 32611-7800

    Visit our web site: www.gophertortoisecouncil.org

  • Now a short quiz-Can you find the tortoise?images courtesy of Jill Kusba

  • How big is this tortoise?HINT: It is a one-year old hatchling

  • Can you find the burrow?

  • The Future