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Articles 1 - 6 of 6

Full-Text Articles in Life Sciences

Widespread Rapid Reductions In Body Size Of Adult Salamanders In Response To Climate Change, Nicholas M. Caruso, Michael W. Sears, Dean C. Adams, Karen R. Lips Jun 2014

Widespread Rapid Reductions In Body Size Of Adult Salamanders In Response To Climate Change, Nicholas M. Caruso, Michael W. Sears, Dean C. Adams, Karen R. Lips

Ecology, Evolution and Organismal Biology Publications

Reduction in body size is a major response to climate change, yet evidence in globally imperiled amphibians is lacking. Shifts in average population body size could indicate either plasticity in the growth response to changing climates through changes in allocation and energetics, or through selection for decreased size where energy is limiting. We compared historic and contemporary size measurements in 15 Plethodon species from 102 populations (9450 individuals) and found that six species exhibited significant reductions in body size over 55 years. Biophysical models, accounting for actual changes in moisture and air temperature over that period, showed a 7.1 ...


Swimming Against The Tide: Resilience Of A Riverine Turtle To Recurrent Extreme Environmental Events, Abigail M. Jergenson, David A. W. Miller, Lorin A. Neuman-Lee, Daniel A. Warner, Fredric J. Janzen Mar 2014

Swimming Against The Tide: Resilience Of A Riverine Turtle To Recurrent Extreme Environmental Events, Abigail M. Jergenson, David A. W. Miller, Lorin A. Neuman-Lee, Daniel A. Warner, Fredric J. Janzen

Ecology, Evolution and Organismal Biology Publications

Extreme environmental events (EEEs) are likely to exert deleterious effects on populations. From 1996 to 2012 we studied the nesting dynamics of a riverine population of painted turtles (Chrysemys picta) that experienced seven years with significantly definable spring floods. We used capture–mark–recapture methods to estimate the relationships between more than 5 m and more than 6 m flood events and population parameters. Contrary to expectations, flooding was not associated with annual differences in survival, recruitment or annual population growth rates of the adult female segment of the population. These findings suggest that female C. pictaexhibit resiliency to ...


Population Genetics Of Blanding’S Turtle (Emys Blandingii) In The Midwestern United States, Arun Sethuraman, Suzanne E. Mcgaugh, Morgan L. Becker, Christopher H. Chandler, James L. Christiansen, Sue Hayden, Andrea Leclere, Jennifer Monson-Miller, Erin M. Myers, Ryan T. Paitz, Jeanine M. Refsnider, Terry J. Vandewalle, Fredric J. Janzen Feb 2014

Population Genetics Of Blanding’S Turtle (Emys Blandingii) In The Midwestern United States, Arun Sethuraman, Suzanne E. Mcgaugh, Morgan L. Becker, Christopher H. Chandler, James L. Christiansen, Sue Hayden, Andrea Leclere, Jennifer Monson-Miller, Erin M. Myers, Ryan T. Paitz, Jeanine M. Refsnider, Terry J. Vandewalle, Fredric J. Janzen

Ecology, Evolution and Organismal Biology Publications

Blanding’s turtle (Emys blandingii) has declined substantially in North America due to anthropogenic activities, leaving populations smaller and increasingly fragmented spatially. We sampled 212 turtles to evaluate variation at eight microsatellite loci within and among 18 populations of E. blandingii across its primary range in the midwestern United States (Illinois, Iowa, Minnesota, and Nebraska). All loci and populations were highly polymorphic. Our analyses also detected considerable genetic structure within and among the sampled localities, and revealed ancestral gene flow of E. blandingii in this region north and east from an ancient refugium in the central Great Plains, concordant with ...


Trans-Gulf Of Mexico Loop Migration Of Tree Swallows Revealed By Solar Geolocation, David W. Bradley, Robert G. Clark, Peter O. Dunn, Andrew J. Laughlin, Caz M. Taylor, Carol M. Vleck, Linda A. Whittingham, David W. Winkler, D. Ryan Norris Jan 2014

Trans-Gulf Of Mexico Loop Migration Of Tree Swallows Revealed By Solar Geolocation, David W. Bradley, Robert G. Clark, Peter O. Dunn, Andrew J. Laughlin, Caz M. Taylor, Carol M. Vleck, Linda A. Whittingham, David W. Winkler, D. Ryan Norris

Ecology, Evolution and Organismal Biology Publications

One of the greatest feats of avian migration is the non-stop crossing of extensive areas of inhospitable habitat such as deserts and seas. Differences in spring and autumn migration routes have been reported in species that cross such barriers, and are thought to have evolved in response to seasonal variation in prevailing wind direction. We tested the hypothesis that migration routes vary seasonally with respect to the Gulf of Mexico in the tree swallow Tachycineta bicolor using solar geolocators attached and retrieved at 4 breeding sites in central North America. We found that 100 % of birds (n = 10) made a ...


Exogenous Application Of Estradiol To Eggs Unexpectedly Induces Male Development In Two Turtle Species With Temperaturedependent Sex Determination, Daniel A. Warner, Elizabeth Addis, Wei-Guo Du, Thane Wibbels, Fredric J. Janzen Jan 2014

Exogenous Application Of Estradiol To Eggs Unexpectedly Induces Male Development In Two Turtle Species With Temperaturedependent Sex Determination, Daniel A. Warner, Elizabeth Addis, Wei-Guo Du, Thane Wibbels, Fredric J. Janzen

Ecology, Evolution and Organismal Biology Publications

Steroid hormones affect sex determination in a variety of vertebrates. The feminizing effects of exposure to estradiol and the masculinizing effects of aromatase inhibition during development are well established in a broad range of vertebrate taxa, but paradoxical findings are occasionally reported. Four independent experiments were conducted on two turtle species with temperature-dependent sex determination (Chrysemys picta and Chelydra serpentina) to quantify the effects of egg incubation temperature, estradiol, and an aromatase inhibitor on offspring sex ratios. As expected, the warmer incubation temperatures induced female development and the cooler temperatures produced primarily males. However, application of an aromatase inhibitor had ...


Immobile And Mobile Life-History Stages Have Different Thermal Physiologies In A Lizard, Rory S. Telemeco Jan 2014

Immobile And Mobile Life-History Stages Have Different Thermal Physiologies In A Lizard, Rory S. Telemeco

Ecology, Evolution and Organismal Biology Publications

Temperature affects multiple aspects of an organism’s biology and thus defines a major axis of the fundamental niche. For ectotherms, variation in the thermal environment is particularly important because most of these taxa have a limited capacity to thermoregulate via metabolic heat production. While temperature affects all life-history stages, stages can differ in their ability to respond to the thermal environment. For example, in oviparous organisms, free-living adults can behaviorally thermoregulate, whereas developing embryos are at the mercy of the nest environment. These differences in the realized thermal environment should select for life-history stages to have different thermal tolerances ...