Download - Po pulations and Home Range Relationships of the Box Turtle

Populations and Home Range Relationships of the

Box Turtle

Populations and Home Range Relationships of the

Box Turtle

Emily MarquardtFebruary 15, 2007

Emily MarquardtFebruary 15, 2007

Box Turtle Life HistoryBox Turtle Life History

Live in mixed habitatwoods (thick leaf litter), open fields, streams

Omnivorous (mushrooms, berries, snails)

Long-lived (human lifespan)

Active April to October

Live in mixed habitatwoods (thick leaf litter), open fields, streams

Omnivorous (mushrooms, berries, snails)

Long-lived (human lifespan)

Active April to October

QuickTime™ and aTIFF (Uncompressed) decompressor

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AmericanNaturalist

1886

AmericanNaturalist

1886



Lucille Stickel’s 1950 paper Populations and Home Range Relationships of the Box Turtle

Lucille Stickel’s 1950 paper Populations and Home Range Relationships of the Box Turtle

Goals:1) To understand the home range relationships

2) To determine the size of thepopulation

Goals:1) To understand the home range relationships

2) To determine the size of thepopulation

Home RangeHome Range

Definition

An area over which an animal normally travels in the course of its daily activities

Definition

An area over which an animal normally travels in the course of its daily activities

“E. T. Go Home”

MethodsMethodsCagle (1939)notching technique (mark-recapture)

Cagle (1939)notching technique (mark-recapture)



MethodsMethods

Breder (1929)

Trailing Device with spindle of thread to track turtles

Breder (1929)

Trailing Device with spindle of thread to track turtles

QuickTime™ and aTIFF (LZW) decompressor




Travels of adult male during 8 days in 1945.

Ranges of 15 turtles occupying parts of a 5 acre plot.

Top: males, Bottom: females.



MethodsMethods

Population Size estimated 2 ways:

1) By collections in one season2) Census trips, standardized for

time and procedure

Population Size estimated 2 ways:

1) By collections in one season2) Census trips, standardized for

time and procedureQuickTime™ and a

TIFF (Uncompressed) decompressorare needed to see this picture.

ResultsResults

2109 turtle collections in 3 years Adults occupy specific home

rangesaverage male: 330 ft, female: 370 feet

Some turtles have 2 home ranges Population size: 4.6 turtles/acre

2109 turtle collections in 3 years Adults occupy specific home

rangesaverage male: 330 ft, female: 370 feet

Some turtles have 2 home ranges Population size: 4.6 turtles/acre

Box Turtle Population Research

1950 to present

Box Turtle Population Research

1950 to present Long term studies Genetics Herbivory Conservation

Long term studies Genetics Herbivory Conservation



Population Tracking Techniques

Population Tracking Techniques

Mark-Recapturefiling notches on marginal scutes

Trailing devices Radio tagging GPS X-ray (eggs)

Mark-Recapturefiling notches on marginal scutes

Trailing devices Radio tagging GPS X-ray (eggs)

Long Term StudiesWildlife Research Center, MD

Long Term StudiesWildlife Research Center, MD

Changes in Population (Stickel 1978)

pronounced decline in population size -1965 to 1975 reduced by half

Home 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

Changes in Population (Stickel 1978)

pronounced decline in population size -1965 to 1975 reduced by half

Home 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

GeneticsGenetics

Promotion of Gene Flow by TransientsKiester et al. (1981)

Transient: turtle that moves through the environment without recrossing areas passed previously

Study documents true transients.- suggests their importance in maintaining

genetic similarity between populations and in aiding spread of advantageous genes

Promotion of Gene Flow by TransientsKiester et al. (1981)

Transient: turtle that moves through the environment without recrossing areas passed previously

Study documents true transients.- suggests their importance in maintaining

genetic similarity between populations and in aiding spread of advantageous genes

Genetic Effects of Persistent Bottleneck

Genetic Effects of Persistent Bottleneck

Kuo & Janzen (2004)

Loss of genetic diversity due to decrease in population size

Bottleneck effects are different for long-lived vs. short-lived species

Kuo & Janzen (2004)

Loss of genetic diversity due to decrease in population size

Bottleneck effects are different for long-lived vs. short-lived species



Kuo & Janzen 2004 cont.Kuo & Janzen 2004 cont.

Used microsatellite markers asses genetic diversity of small disturbed vs. large undisturbed population

Computer 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!

Used microsatellite markers asses genetic diversity of small disturbed vs. large undisturbed population

Computer 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!

HerbivoryHerbivorySeed Dispersal by Florida Box

TurtleLiu et al. (2004)What plant species are dispersed? Does passage through turtle affect germination

rate and percentage?

Current Study by Chris SwarthMeasuring stable isotopes of C and N in toenails and comparing to wetland food items to determine habitats

Seed Dispersal by Florida Box Turtle

Liu et al. (2004)What plant species are dispersed? Does passage through turtle affect germination

rate and percentage?

Current Study by Chris SwarthMeasuring stable isotopes of C and N in toenails and comparing to wetland food items to determine habitats

ConservationConservation

Box Turtle Population Decline

Habitat Loss and Fragmentation Pets Road Kill

Box Turtle Population Decline

Habitat Loss and Fragmentation Pets Road Kill



ConservationConservation

Natural History of Box Turtle in Urbanized Landscape

Budischak et al. (2006)

Turtles persist and grow more quickly in urbanized areas, but suffer higher mortality rates compared to forested landscapes

Natural History of Box Turtle in Urbanized Landscape

Budischak et al. (2006)

Turtles persist and grow more quickly in urbanized areas, but suffer higher mortality rates compared to forested landscapes

Estimating the Effects of Road Mortality on Turtle PopulationsEstimating the Effects of Road Mortality on Turtle PopulationsGibbs and Shriver 2002

Modeling study:integrated road maps & traffic-volume data

with movements of1)small-bodied pond turtles2) large-bodied pond turtles3) terrestrial & semi-terrestrial “land” turtles

Roads networks of Eastern and Central US will limit (3) and (2) but not (1).

Gibbs and Shriver 2002

Modeling study:integrated road maps & traffic-volume data

with movements of1)small-bodied pond turtles2) large-bodied pond turtles3) terrestrial & semi-terrestrial “land” turtles

Roads networks of Eastern and Central US will limit (3) and (2) but not (1).

Translocated Box TurtlesCook (2004)

Translocated Box TurtlesCook (2004)

Site: abandoned airport in NY, 500 ha335 turtles from Long Island

Dispersal, home range establishment, initial survival monitored (radio tracked)

Half developed home ranges28% died and 24% left site

Translocation potentially valuable but long term viability is uncertain

Site: abandoned airport in NY, 500 ha335 turtles from Long Island

Dispersal, home range establishment, initial survival monitored (radio tracked)

Half developed home ranges28% died and 24% left site

Translocation potentially valuable but long term viability is uncertain

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