Increases in extreme environmental events are predicted to be major results of ongoing global climate change and may impact the persistence of species.We examined the effects of heat and cold waves during embryonic de...Increases in extreme environmental events are predicted to be major results of ongoing global climate change and may impact the persistence of species.We examined the effects of heat and cold waves during embryonic development of painted turtles(Chrysemys picta)in natural nests on the occurrence of abnormal shell morphologies in hatchlings.We found that nests exposed to extreme hot temperatures for>60 h produced more hatchlings with abnormalities than nests exposed to extreme hot temperatures for shorter periods,regardless of whether or not nesting females displayed abnormal morphologies.We observed no effect of extreme cold nest temperatures on the occurrence of hatchlings with abnormalities.Moreover,the frequency of nesting females with abnormal shell morphologies was approximately 2-fold lower than that of their offspring,suggesting that such abnormalities are negatively correlated with survival and fitness.Female turtles could potentially buffer their offspring from extreme heat by altering aspects of nesting behavior,such as choosing shadier nesting sites.We addressed this hypothesis by examining the effects of shade cover on extreme nest temperatures and the occurrence of hatchling abnormalities.While shade cover was negatively correlated with the occurrence of extreme hot nest temperatures,it was not significantly correlated with abnormalities.Therefore,female choice of shade cover does not appear to be a viable target for selection to reduce hatchling abnormalities.Our results suggest that increases in the frequency and intensity of heat waves associated with climate change might perturb developmental programs and thereby reduce the fitness of entire cohorts of turtles.展开更多
基金supported by National Science Foundation grant LTREB DEB-0089680 to F.J.Janzensupported by a United States EPA STAR fellowship+1 种基金supported by NSF LTREB DEB-0640932 to F.J.Janzensupported by the Iowa State University Program for Women in Science and Engineering.
文摘Increases in extreme environmental events are predicted to be major results of ongoing global climate change and may impact the persistence of species.We examined the effects of heat and cold waves during embryonic development of painted turtles(Chrysemys picta)in natural nests on the occurrence of abnormal shell morphologies in hatchlings.We found that nests exposed to extreme hot temperatures for>60 h produced more hatchlings with abnormalities than nests exposed to extreme hot temperatures for shorter periods,regardless of whether or not nesting females displayed abnormal morphologies.We observed no effect of extreme cold nest temperatures on the occurrence of hatchlings with abnormalities.Moreover,the frequency of nesting females with abnormal shell morphologies was approximately 2-fold lower than that of their offspring,suggesting that such abnormalities are negatively correlated with survival and fitness.Female turtles could potentially buffer their offspring from extreme heat by altering aspects of nesting behavior,such as choosing shadier nesting sites.We addressed this hypothesis by examining the effects of shade cover on extreme nest temperatures and the occurrence of hatchling abnormalities.While shade cover was negatively correlated with the occurrence of extreme hot nest temperatures,it was not significantly correlated with abnormalities.Therefore,female choice of shade cover does not appear to be a viable target for selection to reduce hatchling abnormalities.Our results suggest that increases in the frequency and intensity of heat waves associated with climate change might perturb developmental programs and thereby reduce the fitness of entire cohorts of turtles.
