Literaturdatenbank
Literaturdatenbank |
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Crawford, R. L., & Doyle, M. J. (2010). Kinosternon subrubrum (eastern mud turtle). mass movement and mortality. Herpetological Review, 41(1), 71.
Added by: Sarina Wunderlich (12 Dec 2010 20:43:02 UTC) |
| Resource type: Journal Article BibTeX citation key: Crawford2010 View all bibliographic details  |
Categories: General Keywords: Habitat = habitat, Kinosternidae, Kinosternon, Kinosternon subrubrum, Nordamerika = North America, Schildkröten = turtles + tortoises Creators: Crawford, Doyle Collection: Herpetological Review |
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| Abstract |
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About 0930 h on 25 April 2009, after a night of heavy rain, we began a survey of paved secondary roads south of Winnie in Chambers County, Texas, USA looking for shorebirds (Scolopacidae, etc.) in rice fields. We drove west on St. Rd. 1985 and then north to and back east on St. Rd. 65, parallel roads about 13 km apart, and beginning and ending on the north-south running St. Rd. 124. We found few shorebirds, but instead encountered an extraordinary mass movement and associated road mortality of the mud turtle Kinosternon subrubrum. Especially on the eastern ends of both roads, and mostly on 1985, we saw hundreds of dead and smashed turtles, some moribund, and perhaps 20 or so more trekking across the roads. The movement we saw of live turtles was entirely north to south across the east-west running roads; we noticed little, if any similar mortality on Rd. 124. We estimated a very conservative 300 dead and dying mud turtles; the total was possibly much higher than this. Even crude quantification was difficult because ofheavy local farm traffic, but at times it was possible to count 20-30 dead turtles in a stretch of 20 m; the circumstances also prevented us from examining specimens and determining sex ratios. This was a monospecific event, as we otherwise noted only two large cooters (Pseudemys sp.), one living and one dead; we also saw a snake (Nerodia sp.) that successfully crossed the road before we could turn around to identify it. We are familiar with similar mass movements (and mortality) following rains by toads, frogs, and salamanders, but saw none of these in this instance, and we had not previously witnessed such a mQvement by turtles. Reports of other significant (though 1nuch smaller) movements of K. subrubrum seem associated with drying habitat (e.g., Strecker and Gibbons et al. In Ernst et al. 1994. Turtles ofthe United States and Canada, p. 172. Smithsonian Inst. Press, Washington, DC). Interpretation ofthe phenomenon we observed was confounded by the inundation of thousands of the surrounding hectares in 2-3 m of salt water .during the storm surge of Hurricane Ike on 13 September 2008. We overheard residents talking of flooding fields to leach the salt before rice could be planted. Nevertheless the movement we saw was coincident with a local deluge of rain. The nearest official rain gauge in Beaumont, Texas, 38 km to the east, recorded only 0.52 inches of rain 24-25 April (Donna Work, Texas Forest Service, pers. comm., 20 May 2009), but around Winnie the total was manifestly much more that that; we heard local commentary on the extraordinary rainfall the night of 24-25 April and saw abundant evidence in flooded fields and residential yards, and water overflowing drainage ditches onto the roads, so the local rainfall must have been considerable. We are grateful to D. Bruce Means and Lora L. Smith for helpful suggestions.
Added by: Sarina Wunderlich |