scholarly journals Environmentally induced phenotypic plasticity explains hatching synchrony in the freshwater turtle Chrysemys picta

2018 ◽  
Vol 329 (6-7) ◽  
pp. 362-372 ◽  
Author(s):  
Jessica K. McGlashan ◽  
Michael B. Thompson ◽  
Fredric J. Janzen ◽  
Ricky-John Spencer
Keyword(s):  
Phenotypic Plasticity ◽  
Chrysemys Picta ◽  
Freshwater Turtle ◽  
Hatching Synchrony

scholarly journals An Examination of Limiting Factors of Chrysemys picta bellii (Western painted turtles) in the Lower Willamette River Basin, Oregon

2021 ◽  
Author(s):  
◽  
James Holley ◽  
Keyword(s):  
River Basin ◽  
Chrysemys Picta ◽  
Limiting Factors ◽  
Freshwater Turtle ◽  
Willamette River ◽  
Turtle Species ◽  
Chrysemys Picta Bellii ◽  
Nesting Activity ◽  
Willamette River Basin ◽  
The Impact

Oregon’s two native freshwater turtle species, Chrysemys picta bellii (Western painted turtle) and Actinemys marmorata (Northwestern pond turtle), have seen significantly reduced population sizes since the founding of Portland in 1845, with estimates of up to 90% for A. marmorata. This project examined turtle nesting activity at 25 sites across a range of turtle populations and habitats around the Lower Willamette River Basin. All discovered turtle nesting activity was found in areas of high solar exposure. We found 93% of over 400 nest attempts to have been depredated across the 25 sites, well above most other reported rates. At several sites, many aborted nest attempts were found atop gravel roadbeds, indicating that lack of appropriate substrate is potentially limiting nesting success. The presence of greater than five pedestrians per hour at turtle nesting areas was correlated with a substantial decrease in nesting attempts suggesting that management of recreational activities may play a role in the amount of nesting activity occurring. Hence, site-specific solutions, such as importing substrate, alteration of path locations or seasonal trail closures to lessen human foot traffic disturbance of turtle nesting attempts, are likely to improve recruitment rates of native turtles in the Lower Willamette Basin. Further studies that improve knowledge of population demographics, the impact of human activities on turtles, and habitat needs of juvenile turtles are needed to support long-term self-sustaining turtle populations.

scholarly journals Reproductive Deficits in Male Freshwater Turtle Chrysemys picta from Cape Cod, Massachusetts1

2007 ◽  
Vol 76 (3) ◽  
pp. 346-352 ◽  
Author(s):  
Noppadon Kitana ◽  
Seung Jae Won ◽  
Ian P. Callard
Keyword(s):  
Chrysemys Picta ◽  
Cape Cod ◽  
Freshwater Turtle

Gonadotropin and estrogen responses in freshwater turtle (Chrysemys picta) from Cape Cod, Massachusetts

2006 ◽  
Vol 149 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Noppadon Kitana ◽  
Wichase Khonsue ◽  
Seung Jae Won ◽  
Valentine A. Lance ◽  
Ian P. Callard
Keyword(s):  
Chrysemys Picta ◽  
Cape Cod ◽  
Freshwater Turtle

Elevated levels of δ15N in riverine Painted Turtles (Chrysemys picta): trophic enrichment or anthropogenic input?

2013 ◽  
Vol 91 (12) ◽  
pp. 899-905 ◽  
Author(s):  
Natalie R. Hofmeister ◽  
Megan Welk ◽  
Steven Freedberg
Keyword(s):  
Trophic Position ◽  
Abiotic Factors ◽  
Chrysemys Picta ◽  
Trophic Levels ◽  
Inorganic Fertilizer ◽  
Freshwater Turtle ◽  
Agricultural Activity ◽  
Painted Turtles ◽  
Animal Populations ◽  
Trophic Enrichment

The natural abundance of stable isotopes of elements in animal tissue is influenced by both biotic and abiotic factors. Biotically, animals feeding at higher trophic levels are enriched in the ratio of 15N:14N (δ15N) relative to their food resources owing to the preferential excretion of 14N. Abiotically, increases in δ15N may also reflect different sources of biologically available nitrogen, including nitrogen resulting from denitrification of inorganic fertilizer. We studied variation in δ15N among freshwater turtle populations to assess spatial variation in δ15N and to determine whether this variation can be attributed to differences in nitrogen source or trophic enrichment. We examined nitrogen and carbon stable isotope ratios in duckweed (genus Lemna L.) and in Painted Turtles (Chrysemys picta (Schneider, 1783)) in aquatic ecosystems expected to be differentially affected by agricultural activity and denitrification of inorganic fertilizer. Across sites, C. picta δ15N was strongly correlated with Lemna δ15N and was elevated in sites influenced by agricultural activity. Furthermore, trophic position of turtles was not associated with δ15N but was consistent with expected values for primary consumers in freshwater systems, indicating that differences in tissue δ15N could be attributed to differences in initial sources of nitrogen in each ecosystem. Our results suggest that care must be taken when attributing differences in isotopic values of animal populations to trophic factors.

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