Literaturdatenbank
Literaturdatenbank |
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Robinson, C. (1989). Orientation and survival of hatchlings and reproductive ecology of the common snapping turtle (chelydra serpentina) in southern quebec. Unpublished thesis , McGill University.
Added by: Sarina Wunderlich (28 Aug 2011 21:15:20 UTC) |
| Resource type: Thesis/Dissertation BibTeX citation key: Robinson1989 View all bibliographic details  |
Categories: General Keywords: Chelydra, Chelydra serpentina, Chelydridae, Habitat = habitat, Nordamerika = North America, Schildkröten = turtles + tortoises, Verhalten = ethology, Zeitigung = incubation Creators: Robinson Publisher: McGill University |
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| Abstract |
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The orientation and survival of neonate snapping turtles (Chelydra serpentina) were studied in 1986 and 1987. Orientation mechanisms were tested in an outdoor parabolic arena. These experiments suggested that positive geotaxis was a dominant cue directing neonate snapping turtles to water. Hatchling survival and movement from nest to water were studied in Calumet, Quebec using isotope tagging. A highly significant number of hatchlings (95%) released on sloped nest sites were positively geotactic. Hatchlings released on level ground moved in random directions. Eighty-two percent of hatchlings from nests within 18 m of the shoreline were successful in reaching water. Incidence of mortality was greatest for hatchlings from nests between 121 and 165 m from water. Mortality resulted from vehicles and predation by bullfrogs (Rana catesbieana) and meadow voles (Microtus pennsylvanicus). Female carapace length was positively correlated with clutch size and mean egg diameter. Egg diameters were positively correlated with hatchling weights. Clutch sizes of nests more than 100 m from water were larger than those closer to water.
Added by: Sarina Wunderlich |