Progress 01/01/05 to 12/31/05
Outputs
I am using mark-recapture techniques to determine the population abundance, structure, and movement patterns of painted turtles. Although many populations of freshwater turtles have declined in abundance presumably due to habitat loss and fragmentation, few quantitative studies of such a relationship have occurred. The study focuses on 5 wetland complexes that include 5 permanent wetlands and about 90 temporary wetlands. Most of the temporary ponds dry up during summer, leaving only the deeper permanent ponds available as over-wintering sites. In 3 field seasons, I captured over 2,000 individual turtles and have a total of over 10,000 recaptures. Recapture data of marked individuals will be used to estimate turtle survival and movement rates. Road mortality surveys have also been conducted weekly along a 4-mile stretch of Highway 93 and along 2 miles of secondary roads. All mortalities were examined to determine individual identification, sex, and age class when
possible. Between 230 and 420 turtles have been killed on Highway 93 each year.
Impacts
This research addresses the potential effects of fragmentation due to highways on turtle populations and movements.
Publications
- No publications reported this period
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Progress 01/01/04 to 12/30/04
Outputs
I am using mark-recapture techniques to determine the population abundance, structure, and movement patterns of painted turtles. Although many populations of freshwater turtles have declined in abundance presumably due to habitat loss and fragmentation, few quantitative studies of such a relationship have occurred. My research addresses the potential effects of fragmentation due to highways on turtle populations and movements. The study focuses on 5 wetland complexes that include 5 permanent wetlands and about 90 temporary wetlands. Most of the temporary ponds dry up during summer, leaving only the deeper permanent ponds available as over-wintering sites. Painted turtles were captured using a variety of techniques including basking traps, seines, and dip nets. In the 3 field seasons, I marked over 2,000 individual turtles and have a total of over 10,000 captures. Recapture data of marked individuals will be used to estimate turtle survival rates and movements. Road
mortality surveys have been conducted approximately once a week during all 3 field seasons. Our crews documented road-killed turtles and other wildlife species along a 4-mile stretch of Highway 93 and also along 2 miles of secondary roads. All mortalities were examined to determine individual identification, sex, and age class when possible. Between 230 and 420 turtles have been killed on Highway 93 each year.
Impacts
This research will elucidate the potential effects of highways on populations. The results of the road mortality portion of the study will also help determine placement of new wildlife crossing structures for the Highway 93 reconstruction project.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
The primary objective of this study is to determine to what extent highways and secondary roads act as barriers to turtle movements. In order to determine this, the amount of turtle movement, distance of movements, and what segment of the population is moving are also being studied. We recorded approximately 6,330 captures of 1,640 individual painted turtles during the 2002 and 2003 field seasons. All individuals were measured, weighed, tagged, and released into the original pond of capture. Movements between ponds were detected both years. Most of the movements were observed in adult males, although females, juveniles, and hatchlings were all observed to move between ponds. Most movements were less than 300 m. We observed 354 road-killed turtles in the 4-mile section of Highway 93 and six in the 1.5-mile section of Mollman Pass Trail Road during the summer of 2002, and 415 road-killed turtles in 2003. Other road-killed animals included 50 muskrats, 60 birds, numerous
snakes and small mammals, one deer and one coyote. One more field season (2004) will precede analysis of data and a dissertation.
Impacts
Native American mythology suggests that the earth rides on the back of a turtle. The proposed widening of US Highway 93 has the potentially to cause additional mortality on the turtle population south of Ronan, Montana. The effects of the current fragmentation of this population and the potential effects of widening the highway are being evaluated.
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
The primary objective of this study is to determine to what extent highways and secondary roads act as barriers to turtle movements. In order to determine this, the amount of turtle movement, distance of movements, and what segment of the population is moving are also being studied. We recorded 2,015 captures of 915 painted turtles individuals. All individuals were measured, weighed, tagged, and released into the original pond of capture. Preliminary results indicate that 26 movements between ponds were observed based on recapture data. Most (69%) of the movements were observed in adult males, although females, juveniles, and hatchlings were all observed to move between ponds. Most movements were less than 300 m, however the longest recorded distance was approximately 1,200 m. None of the turtles were observed to cross Highway 93, but six turtles have crossed Mollman Pass Trail Road, a paved secondary road. We observed 354 road-killed turtles in the 4-mile section of
Highway 93 and six in the 1.5-mile section of Mollman Pass Trail Road. Most (44%) road mortalities were unidentifiable as to sex or age of the turtle, although approximately 32% were adults. Slightly more males (10%) were identified than females (9%). Twelve road-killed turtles appeared to be marked but only five of these could be positively identified.
Impacts
Native American mythology suggests that the earth rides on the back of a turtle. The proposed widening of US Highway 93 has the potentially to cause additional mortality on the turtle population south of Ronan, Montana. The effects of the current fragmentation of this population and the potential effects of widening the highway are being evaluated.
Publications
- No publications reported this period
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