Literaturdatenbank
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Cotter, J. (2010). Effects of natural incubation regimes and fitness of hatchling midland painted turtles (chrysemys picta marginata). Unpublished thesis , John Carroll University, University Heights, Ohio.
Added by: Sarina Wunderlich (30 Jun 2012 22:00:42 UTC) |
| Resource type: Thesis/Dissertation BibTeX citation key: Cotter2010 View all bibliographic details  |
Categories: General Keywords: Chrysemys, Chrysemys picta, Emydidae, Habitat = habitat, Nordamerika = North America, Schildkröten = turtles + tortoises, Zeitigung = incubation Creators: Cotter Publisher: John Carroll University (University Heights, Ohio) |
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| Abstract |
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The objectives of the current study were to understand how biotic and abiotic factors impact hatchling secondary sex ratios and indirect measures of fitness (i.e., sprint speed and righting time) of Chrysemys picta marginata in northeastern Ohio, U.S.A. It was predicted that canopy cover would lower nest temperatures relative to more open nest locations and therefore produce more male-biased hatchling secondary sex ratios, larger hatchlings, and hatchlings with greater indirect fitness measures. Biotic and abiotic factors recorded from each nest were directly correlated with mean nest temperatures, with north facing canopy cover having the largest influence. Additionally, clutch size was directly correlated with percentage of males; however,, mean nest temperatures were not. Male hatchlings were larger than their female cohorts and had faster sprint speeds along a 1-m water-track, whereas the female hatchlings were faster at righting themselves. Overall, this study has illustrated no direct correlation between the amount of canopy cover and hatchling secondary sex ratios as indicated by other studies. This may be due to insufficient variability in ambient temperatures during the course of the study. However, this study did indicate significant variation in the amount of canopy over the nests which affected hatchling righting time, but not hatchling sprint speed.
Added by: Sarina Wunderlich |