Literaturdatenbank
Literaturdatenbank |
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Wilson, T. P. (2004). Ecology of the spotted turtle, clemmys guttata at the western range limit. Unpublished thesis , Eastern Illinois University.
Added by: Sarina Wunderlich (06 Jul 2014 16:17:30 UTC) |
| Resource type: Thesis/Dissertation BibTeX citation key: anon2004.16606 View all bibliographic details  |
Categories: General Keywords: Habitat - habitat, Nordamerika - North America, Schildkröten - turtles + tortoises Creators: Wilson Publisher: Eastern Illinois University |
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| URLs http://thekeep.eiu.edu/theses/1188 |
| Abstract |
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Clemmys guttata is a northeastern and coastal species which reaches the western range limit in Illinois. Three small populations of this species occur along the Des Plaines River in Will Co., IL. The ecology of a northern Illinois population of Spotted turtles, Clemmys guttata, was investigated using capturerecapture and biotelemetric techniques from May 1992 to June 1993 at Lockport Nature Preserve in Will Co. This study was conducted to gather the ecological data necessary to design a management plan for the species. These research criteria included extent of turtle movements within the study site, habitat use, estimate population size, determine annual activity cycle, estimate average home range, and determine how the ecology of this species in Illinois differs from eastern populations. Turtles were captured by hand or mUddling. A total of 98 turtles have been captured at the Lockport site. Population size was estimated at 115 turtles using the Schnabel method from recapture data. Population density was calculated to be 2.2 turtles/ha via the Schnabel method. Radiotelemetry was used to follow the movements of eight adult spotted turtles. Lockport spotted turtle's home ranges averaged 1.36 ha. Females had significantly larger home ranges than males. Terrestrial long distance movements were restricted to nesting females and core areas within the home range shifted seasonally. In Illinois this turtle is closely associated with cattail marsh and sedge meadow habitat. Spotted turtles were diurnal except for nesting females. Annually the turtles emerge from brumation in March; are active until late June; aestivate from July to September; are active for shorter periods from October to early November; and enter brumation in late November and December. Peak activity periods were· correlated with temperature and changed seasonally. Typically, turtles were active until their core temperatures reached the mean preferred temperature (21-25 C), and above that they retreat to the water or shade. Biophysical temperatures were taken to determine the relationship between cloacal and environmental temperatures. Cloacal temperatures of spotted turtles ranged form 4.4 C to 33.0 C. Cloacal temperatures varied depending upon the ambient temperature and behavior, but were strongly correlated to the environmental temperature that was in close association with the turtle. Lockport spotted turtles were observed copulating from March through May. Nesting was observed from June 18 to 26. A single clutch is laid containing 3 to 5 eggs with hard expansible shells. Turtles grew rapidly through the early years but growth rates leveled off at seven years (approximate age of maturity). Males were significantly larger than females at age classes 2-6. Shell abnormalities of several types occurred among members of this population including supernumerary scutes, cracking, and erosion of scutes. Causes may include inbreeding and/or environmental factors.
Added by: Sarina Wunderlich |