Po pulations and Home Range Relationships of the Box Turtle

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Po pulations and Home Range Relationships of the Box Turtle. Emily Marquardt February 15, 2007. Box Turtle Life History. Live in mixed habitat woods (thick leaf litter), open fields, streams Omnivorous (mushrooms, berries, snails) Long-lived (human lifespan) Active April to October. - PowerPoint PPT Presentation

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<ul><li><p>Populations and Home Range Relationships of the Box Turtle</p><p>Emily MarquardtFebruary 15, 2007</p></li><li><p>Box Turtle Life HistoryLive in mixed habitatwoods (thick leaf litter), open fields, streamsOmnivorous (mushrooms, berries, snails)Long-lived (human lifespan)Active April to October</p></li><li><p>AmericanNaturalist</p><p>1886</p></li><li><p>Lucille Stickels 1950 paper Populations and Home Range Relationships of the Box TurtleGoals:1) To understand the home range relationships</p><p>2) To determine the size of thepopulation</p></li><li><p>Home RangeDefinition</p><p>An area over which an animal normally travels in the course of its daily activities</p><p>E. T. Go Home</p></li><li><p>MethodsCagle (1939)notching technique (mark-recapture)</p></li><li><p>Methods</p><p>Breder (1929)</p><p>Trailing Device with spindle of thread to track turtles</p></li><li><p>Travels of adult male during 8 days in 1945.Ranges of 15 turtles occupying parts of a 5 acre plot. Top: males, Bottom: females.</p></li><li><p>MethodsPopulation Size estimated 2 ways:By collections in one seasonCensus trips, standardized for time and procedure</p></li><li><p>Results2109 turtle collections in 3 yearsAdults occupy specific home rangesaverage male: 330 ft, female: 370 feetSome turtles have 2 home rangesPopulation size: 4.6 turtles/acre</p></li><li><p>Box Turtle Population Research</p><p>1950 to presentLong term studiesGeneticsHerbivoryConservation</p></li><li><p>Population Tracking Techniques Mark-Recapturefiling notches on marginal scutes Trailing devices Radio tagging GPS X-ray (eggs)</p></li><li><p>Long Term StudiesWildlife Research Center, MDChanges in Population (Stickel 1978)pronounced decline in population size -1965 to 1975 reduced by halfHome Range Behavior (Stickel 1989)-size of home range did not differ significantly over 40 years Fifty year trends in Population (Hall 1999)- greater than 75% decline in population-found individuals greater than 70 years old</p></li><li><p>GeneticsPromotion of Gene Flow by TransientsKiester et al. (1981)</p><p>Transient: turtle that moves through the environment without recrossing areas passed previously</p><p>Study documents true transients.-suggests their importance in maintaining genetic similarity between populations and in aiding spread of advantageous genes</p></li><li><p>Genetic Effects of Persistent BottleneckKuo &amp; Janzen (2004)</p><p>Loss of genetic diversity due to decrease in population size</p><p>Bottleneck effects are different for long-lived vs. short-lived species</p></li><li><p>Kuo &amp; Janzen 2004 cont. Used microsatellite markers asses genetic diversity of small disturbed vs. large undisturbed populationComputer simulations:effective population size for small pop. (to maintain 90% alleles) is:300 over 200 yrs Long-live species could mask accelerated rate of genetic drift!</p></li><li><p>HerbivorySeed Dispersal by Florida Box TurtleLiu et al. (2004)What plant species are dispersed? Does passage through turtle affect germination rate and percentage?</p><p>Current Study by Chris SwarthMeasuring stable isotopes of C and N in toenails and comparing to wetland food items to determine habitats</p></li><li><p>ConservationBox Turtle Population Decline</p><p>Habitat Loss and FragmentationPetsRoad Kill</p></li><li><p>ConservationNatural History of Box Turtle in Urbanized LandscapeBudischak et al. (2006)Turtles persist and grow more quickly in urbanized areas, but suffer higher mortality rates compared to forested landscapes</p></li><li><p>Estimating the Effects of Road Mortality on Turtle PopulationsGibbs and Shriver 2002Modeling study:integrated road maps &amp; traffic-volume data with movements of1)small-bodied pond turtles2) large-bodied pond turtles3) terrestrial &amp; semi-terrestrial land turtles</p><p>Roads networks of Eastern and Central US will limit (3) and (2) but not (1).</p></li><li><p>Translocated Box TurtlesCook (2004)Site: abandoned airport in NY, 500 ha335 turtles from Long IslandDispersal, home range establishment, initial survival monitored (radio tracked)Half developed home ranges28% died and 24% left site</p><p>Translocation potentially valuable but long term viability is uncertain</p></li><li><p>THE</p><p>END</p></li></ul>