A study of the Red-Bellied Turtle Population, Pseudemys rubriventris, at Codorus State Park Rick...
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A study of the Red-Bellied Turtle Population, Pseudemys rubriventris, at Codorus State Park Rick Harabin Department of Biological Sciences, York College of Pennsylvania INTRODUCTION To better understand the population size and habitat use of red-bellied turtles, I conducted a mark-recapture study at Lake Marburg in Codorus State Park, PA. •The red-bellied turtle is located in the coastal plain of the mid-Atlantic region (Ernst et al. 1994) •The red-bellied turtle is a state (PA) threatened species due to habitat degradation and pollution (Swarth 1999) • Habitat diversity is crucial and consists of deep and shallow foraging areas, numerous basking sites and meadows or fields for reproduction (Swarth 1999) • Red-bellied turtle may be outcompeted by other native and invasive turtle species, in particular the red-eared slider (Trachemys scripta) (Polo-Cavia et al. 2008, Urban 2006 and Tran et al. 2007) • Habitat use may be partitioned seasonally, annually, or by the sexes etc.; The understanding of these different patterns, along with philopatry and home ranges are all important to the management and design of conservation techniques (Berstein et al. 2006 and Tran et al. 2007) OBJECTIVES To help determine placement of multiple protected reproductive sites How? • To begin to estimate population sizes for the four different turtles species (red-bellied, painted, red- eared slider and yellow-bellied) • To determine where the red-bellied turtles are and how they move between sample areas within Lake Marburg in order to help identify home range size and potential nesting locations. METHODS Three trap site locations were picked near already placed basking platforms. The traps were designed to minimized stress and danger placed on the captured turtles but to capitalize their natural behavior of basking. Each trap was checked for captives daily, for a time period spanning 7- 15 days per month. The captured turtles’ measurements (mass, carapace height, length and width) and # of parasites were recorded, and their carapace was marked for future identification (Ernst 1974). Population Estimation & 95% Confidence Intervals (Schnabel Method) RESULTS 0 10 20 30 40 Red-Bellied Painted R ed-Eared Slider Yellow -Bellied Slider Figure 4.Fourspecies ofturtles captured on Lake M arburg (C odurus State Park)at3 differentlocations. C aptured Location # ofT urtles CONCLUSIONS • My estimate of the red-bellied turtle population is a very low estimate making my work crucial for further and more elaborate work to protect the species (Table1.) • The red-bellied turtles’ mean masses (Data not shown) were consistent with previous known masses (Swarth 1999, Ernst 1985 and Ernst et al. 1994) • The red-eared slider’s population estimation could not be determined with no recaptures but this could be due to their excessively large population (Krebs 1999) • The greater number of painted turtles captured in July’s (Figure 1.), may be due to their higher tolerance of warmer water (Ernst 1994 and Polo-Cavia et al. 2008) • The red-bellied turtle exhibits a possible nesting and feeding area shown by the recapture at a different location (Table 2.) • There were lots of turtles located at Chapel Cove, making this a candidate for possible nesting locations at nearby fields (Figure 4.) LITERATURE CITED Bernstein, N.P., Rightsmeier, R.J. and Black, R.W. 2007. Home Range and Philopatry in the Ornate Box Turtle, Terrapene ornata ornata, In Iowa. The American Midland Naturalist . 157:162-174. Ernst, C.H., Lovich, J.E. and Barbour, R.W. 1994. Turtles of the United States and Canada . Smithsonian Institution Press, Washington, D.C. Polo-Cavia, N., Lopez, P. and Martin, J. 2008. Interspecific Differences in Responses to Predation Risk May Confer Competitive Advantages to Invasive Freshwater Turtle Species. Ethology 114:115-123. Swarth, C.W. 1999. Natural History and Reproductive Biology of the Red-Bellied Turtle (Pseudemys rubriventris). P73-83 In: Swarth, C.W., Roosenburg, W.M. and Kiviat, E. (eds.). Conservation and Ecology of Turtles of the Mid-Atlantic Region: A Symposium . Bibliomania! Publishing Co., Salt Lake City, Ut. Urban, C. 2006. Common Wealth of Pennsylvania, Pennsylvania Invasive Species Council Aquatic Invasive Species Management Plan. Available From http://www.agriculture.state.pa.us/agriculture/lib/agriculture/gisfiles/PA_AISMP.pdf. Accessed 09 September 09 . Tran, S.L., Moorhead, D.L. and McKenna, K.C. 2007Habitat Selection by Native Turtles in a Lake Erie Wetland, USA. The American Midland Naturalist. 158:16-28. Special Thanks, Dr. Jessica Nolan Assistant Professor Biology York College of PA Country Club Road York, PA 17405 (717)815-6449 [email protected] Andy St. John-Park Manager Bureau of State Parks Resource Management Section 8th. Fl. Rachel Carson State Office Building 400 Market Street - P.O. Box 8551 Harrisburg, PA 17105-8551 direct line - (717) 772-0242 [email protected] Sally Ray Zoologist Pennsylvania Natural Heritage Program Western Pennsylvania Conservancy 208 Airport Drive Middletown, PA 17057 [email protected] Home office: (717) 292-4881 Ct = total number of individuals captured in sample t Rt = number of individuals already marked in sample t Mt = total number of individuals marked in population at sample t June July August 0 1 2 3 Red-bellied Painted Red-eared slider Yellow-belly slider Figure 1. The mean (+/- SEM) # of turtles/per day that were captured over a period of 7-15 days per month. The mean with a * shows an significant difference (ANOVA test) between # painted captured to all other species with a P values 0.01. * Time (Month) # Of Turtles Captured
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Transcript of A study of the Red-Bellied Turtle Population, Pseudemys rubriventris, at Codorus State Park Rick...
A study of the Red-Bellied Turtle Population, Pseudemys rubriventris, at Codorus State Park
Rick Harabin
Department of Biological Sciences, York College of Pennsylvania
INTRODUCTION
To better understand the population size and habitat use of red-bellied turtles, I conducted a mark-recapture study at Lake Marburg in Codorus State Park, PA. •The red-bellied turtle is located in the coastal plain of the mid-Atlantic region (Ernst et al. 1994)•The red-bellied turtle is a state (PA) threatened species due to habitat degradation and pollution (Swarth 1999)• Habitat diversity is crucial and consists of deep and shallow foraging areas, numerous basking sites and meadows or fields for reproduction (Swarth 1999)• Red-bellied turtle may be outcompeted by other native and invasive turtle species, in particular the red-eared slider (Trachemys scripta) (Polo-Cavia et al. 2008, Urban 2006 and Tran et al. 2007)• Habitat use may be partitioned seasonally, annually, or by the sexes etc.; The understanding of these different patterns, along with philopatry and home ranges are all important to the management and design of conservation techniques (Berstein et al. 2006 and Tran et al. 2007)
OBJECTIVES
To help determine placement of multiple protected reproductive sitesHow?• To begin to estimate population sizes for the four different turtles species (red-bellied, painted, red- eared slider and yellow-bellied)• To determine where the red-bellied turtles are and how they move between sample areas within Lake Marburg in order to help identify home range size and potential nesting locations.
METHODS
Three trap site locations were picked near already placed basking platforms.
The traps were designed to minimized stress and danger placed on the captured turtles but to capitalize their natural behavior of basking.
Each trap was checked for captives daily, for a time period spanning 7-15 days per month.
The captured turtles’ measurements (mass, carapace height, length and width) and # of parasites were recorded, and their carapace was marked for future identification (Ernst 1974).
Population Estimation & 95% Confidence Intervals (Schnabel Method)
RESULTS
0
10
20
30
40Red-Bellied
Painted
Red-Eared Slider
Yellow-Bellied Slider
Figure 4. Four species of turtles captured on Lake Marburg(Codurus State Park) at 3 different locations.
Captured Location
# o
f T
urt
les
CONCLUSIONS
• My estimate of the red-bellied turtle population is a very low estimate making my work crucial for further and more elaborate work to protect the species (Table1.)• The red-bellied turtles’ mean masses (Data not shown) were consistent with previous known masses (Swarth 1999, Ernst 1985 and Ernst et al. 1994)• The red-eared slider’s population estimation could not be determined with no recaptures but this could be due to their excessively large population (Krebs 1999)• The greater number of painted turtles captured in July’s (Figure 1.), may be due to their higher tolerance of warmer water (Ernst 1994 and Polo-Cavia et al. 2008)• The red-bellied turtle exhibits a possible nesting and feeding area shown by the recapture at a different location (Table 2.)• There were lots of turtles located at Chapel Cove, making this a candidate for possible nesting locations at nearby fields (Figure 4.)
LITERATURE CITEDBernstein, N.P., Rightsmeier, R.J. and Black, R.W. 2007. Home Range and
Philopatry in the Ornate Box Turtle, Terrapene ornata ornata, In Iowa. The American Midland Naturalist. 157:162-174.Ernst, C.H., Lovich, J.E. and Barbour, R.W. 1994. Turtles of the United States and Canada. Smithsonian Institution Press, Washington, D.C.
Polo-Cavia, N., Lopez, P. and Martin, J. 2008. Interspecific Differences in Responses to Predation Risk May Confer Competitive Advantages to Invasive Freshwater Turtle Species. Ethology
114:115-123.Swarth, C.W. 1999. Natural History and Reproductive Biology of the Red-Bellied
Turtle (Pseudemys rubriventris). P73-83 In: Swarth, C.W., Roosenburg, W.M. and Kiviat, E. (eds.). Conservation and Ecology of Turtles of the Mid-Atlantic Region: A Symposium. Bibliomania!
Publishing Co., Salt Lake City, Ut. Urban, C. 2006. Common Wealth of Pennsylvania, Pennsylvania Invasive Species
Council Aquatic Invasive Species Management Plan. Available From http://www.agriculture.state.pa.us/agriculture/lib/agriculture/gisfiles/PA_AISMP.pdf. Accessed 09 September 09.
Tran, S.L., Moorhead, D.L. and McKenna, K.C. 2007Habitat Selection by Native Turtles in a Lake Erie Wetland, USA. The American Midland Naturalist. 158:16-28.
Special Thanks,
Dr. Jessica Nolan Assistant Professor Biology York College of PA
Country Club Road York, PA 17405 (717)815-6449 [email protected]
Andy St. John-Park Manager Bureau of State Parks Resource Management Section 8th. Fl. Rachel Carson State Office Building 400 Market Street - P.O. Box 8551 Harrisburg, PA 17105-8551 direct line - (717) 772-0242 [email protected]
Sally Ray Zoologist Pennsylvania Natural Heritage Program Western Pennsylvania Conservancy 208 Airport Drive Middletown, PA 17057 [email protected] Home office: (717) 292-4881
Ct = total number of individuals captured in sample tRt = number of individuals already marked in sample tMt = total number of individuals marked in population at sample t
June
July
August0
1
2
3Red-belliedPaintedRed-eared sliderYellow-belly slider
Figure 1. The mean (+/- SEM) # of turtles/per day that were captured over a periodof 7-15 days per month. The mean with a * shows an significant difference (ANOVA test) between # painted captured to all other species with a P values 0.01.
*
Time (Month)
# O
f T
urt
les
Cap
ture
d
