Literaturdatenbank
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Sajwaj, T. D., & Lang, J. W. (2000). Thermal ecology of blanding's turtle in central minnesota. Chelonian Conservation & Biology, 3(4), 626–636.
Added by: Admin (21 Nov 2009 11:53:23 UTC) |
| Resource type: Journal Article BibTeX citation key: Sajwaj2000 View all bibliographic details  |
Categories: General Keywords: Emydidae, Emydoidea, Emydoidea blandingii, Habitat = habitat, Nordamerika = North America, Physiologie = physiology, Schildkröten = turtles + tortoises Creators: Lang, Sajwaj Collection: Chelonian Conservation & Biology |
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| Abstract |
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We studied daily and seasonal patterns of body temperature (Tb) in free-ranging Blanding's turtles (Emydoidea blandingii) in central Minnesota at the northwestern edge of the species' range. We recorded the internal Tb of 29 turtles (11 males, 17 females, 1 juvenile) living in shrub swamps for intervals of 1 to 15 months, for two summers and an intervening winter, via surgically implanted, temperature-sensitive data loggers. External shell temperatures were monitored with temperature-sensitive radio transmitters. Turtles were active from May to October, and they exhibited three daily patterns of Tb:thermoregulating (Tb max-min 11C), thermoconforming (Tb max-min 6C), and intermediate (11C Tb max-min 6C). A daily sequence consisted of: a rapid or gradual heating phase, a plateau phase, a rapid cooling phase, followed by a prolonged phase of gradual cooling. On clear sunny days, the dominant pattern changed seasonally. In May, most turtles (90%) thermoregulated, whereas in July-October, only about half (45%) did. During November-April, turtles overwintered underwater beneath ice at Tb 2C. Sex differences in thermal behavior were apparent. In comparison with males, females thermoregulated more often and maintained higher Tb in the fall, but not in the spring. These differences may reflect different reproductive activities. The Tb of this aquatic turtle was dependent on water temperature and on exposure to solar radiation mediated by basking behavior. Blanding's turtle is an active thermoregulator in a northern climate. Our study highlights the profound influence of water temperature on turtle Tb throughout the annual cycle. Relevant conservation concerns include minimizing disturbances to thermoregulating turtles, and maintaining intact and diverse aquatic habitats in suitable wetlands.
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