The Effects of Prescribed Fire on a Population of Eastern Box Turtles (Terrapene carolina) in Southwest Michigan

We report here on previous and ongoing efforts to understand how prescribed fires affect a population of Eastern Box Turtles (Terrapene Carolina) in Southwest Michigan. Work with the animals began in 2007, and a larger proportion of animals we have found have burn injuries. Those animals which are burned show varying degrees of resilience to their injuries with some animals succumbing quickly and dying over a short period of time while others with extensive injuries are able to recover over several years

Reducing the Potential for Human–Snake Encounters in a Recreational Park

Parks and outdoor recreation areas often struggle to balance management for outdoor recreation with the protection of native flora and fauna. Additional complications can arise for land managers when recreation occurs in areas shared with wildlife that are perceived by humans to be dangerous. Despite these issues, many parks may inadvertently increase the potential for human–wildlife encounters through the creation of artificial forest gaps used for recreational purposes. We determined the potential for human encounters with venomous copperhead snakes (Agkistrodon contortrix) at a recreational park in southern Indiana before and after several simulated closures of recreational forest gaps. By restricting human access to artificial forest gaps, encounters with copperheads could be reduced by 1.5 to 8 times the observed encounter rate. We discuss conservation implications and provide suggestions for recreational park managers facing related concerns of human–wildlife encounters

Climatic and geographic predictors of life history variation in Eastern Massasauga (Sistrurus catenatus): A range-wide synthesis

Elucidating how life history traits vary geographically is important to understanding variation in population dynamics. Because many aspects of ectotherm life history are climate-dependent, geographic variation in climate is expected to have a large impact on population dynamics through effects on annual survival, body size, growth rate, age at first reproduction, size-fecundity relationship, and reproductive frequency. The Eastern Massasauga (Sistrurus catenatus) is a small, imperiled North American rattlesnake with a distribution centered on the Great Lakes region, where lake effects strongly influence local conditions. To address Eastern Massasauga life history data gaps, we compiled data from 47 study sites representing 38 counties across the range. We used multimodel inference and general linear models with geographic coordinates and annual climate normals as explanatory variables to clarify patterns of variation in life history traits. We found strong evidence for geographic variation in six of nine life history variables. Adult female snout-vent length and neonate mass increased with increasing mean annual precipitation. Litter size decreased with increasing mean temperature, and the size-fecundity relationship and growth prior to first hibernation both increased with increasing latitude. The proportion of gravid females also increased with increasing latitude, but this relationship may be the result of geographically varying detection bias. Our results provide insights into ectotherm life history variation and fill critical data gaps, which will inform Eastern Massasauga conservation efforts by improving biological realism for models of population viability and climate change

Evolution of the Aging Brain Transcriptome and Synaptic Regulation

Alzheimer's disease and other neurodegenerative disorders of aging are characterized by clinical and pathological features that are relatively specific to humans. To obtain greater insight into how brain aging has evolved, we compared age-related gene expression changes in the cortex of humans, rhesus macaques, and mice on a genome-wide scale. A small subset of gene expression changes are conserved in all three species, including robust age-dependent upregulation of the neuroprotective gene apolipoprotein D (APOD) and downregulation of the synaptic cAMP signaling gene calcium/calmodulin-dependent protein kinase IV (CAMK4). However, analysis of gene ontology and cell type localization shows that humans and rhesus macaques have diverged from mice due to a dramatic increase in age-dependent repression of neuronal genes. Many of these age-regulated neuronal genes are associated with synaptic function. Notably, genes associated with GABA-ergic inhibitory function are robustly age-downregulated in humans but not in mice at the level of both mRNA and protein. Gene downregulation was not associated with overall neuronal or synaptic loss. Thus, repression of neuronal gene expression is a prominent and recently evolved feature of brain aging in humans and rhesus macaques that may alter neural networks and contribute to age-related cognitive changes

Lifelong testicular differentiation in Pleurodeles waltl (Amphibia, Caudata)

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens