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Amphibian populations, including those of lungless salamanders (Plethodontidae), are susceptible to population declines, especially considering current and predicted climate change. Like many organisms, plethodontid salamanders exhibit reproductive plasticity to maximize population growth in response to environmental conditions. A better understanding of the external causes of reproductive plasticity can provide more accurate population models through the explicit incorporation of such drivers. To this end, we sampled Southern Pygmy Salamanders (Desmognathus wrighti) along a 1345-m elevational gradient in Great Smoky Mountains National Park, USA, to determine the effects of body size and elevation on reproductive investment. Using Bayesian mixed effects models, we assessed whether body size, elevation, or a combination of these factors best explained the probability an individual was gravid, the number of ova in gravid females, and the number of testis lobes in mature males. We found that the interaction of body size and elevation best explained each reproductive measure. Larger females were generally more likely to be gravid, with annual reproduction in fully mature females at low to mid-elevations and roughly biennial reproduction at high elevations. We also found a positive relationship between body size and ova counts at low and mid-elevations, but despite a reduction in reproductive frequency at higher elevations, we found no effect of body size on ova count. In addition, the addition of testis lobes, which has commonly been used as a proxy of age in plethodontid salamanders, occurred at larger body sizes with increasing elevation. Our findings support previous work showing a relationship between body size and reproductive ecology in desmognathine salamanders while providing insight into the complexity of this relationship in the context of elevational clines. Reproductive ecology significantly influences population dynamics; thus, further refinement of these observed patterns and their underlying causes is necessary to advance plethodontid salamander population ecology. [ABSTRACT FROM AUTHOR]

Maladaptive movement behavior is a leading cause of failure for reptile reintroductions, thus characterizing movement for translocated populations is important to project success. From 2014–2016 we radio‐tracked 183 immature reintroduced alligator snapping turtles (Macrochelys temminckii) using very high frequency telemetry in a stream in southern Illinois, USA. We assessed environmental, temporal, morphometric, and microhabitat factors influencing movement, including post‐release dispersal from reintroduction sites, movement probability, and step length. We used directional statistics to investigate the effects of precipitation and age on directional movement in the stream. Numerous factors influenced active movement, including ambient temperatures, time since release, use of log jams, turtle size, and age. Precipitation had an age‐biased effect on movement. Directional analyses suggested that movement was largely passive as turtles were swept downstream with increased discharge. Overall, the behavior of reintroduced alligator snapping turtles was similar to that reported in wild populations. Passive downstream transport has implications for reintroduced and natural populations as a force for unintentional emigration in channelized streams under current conditions and future high flow regimes. [ABSTRACT FROM AUTHOR]

Fire is a vital management tool for maintaining prairie ecosystems. Prescribed burns control invasive species, regulate succession, stimulate plant growth, and are a cheap and effective method for removing excess biomass; however, fire can also inadvertently cause wildlife mortality, placing land managers in a challenging situation. Turtles are especially at risk of mortality from fire because of their low mobility and population sensitivity to reductions in adult survival. We studied ornate box turtles (Terrapene ornata) at 3 sites in Illinois, USA, from 2019–2022 to determine the best predictors of above‐ground activity so land managers can conduct prescribed burns when turtles are underground. We used turtle shell temperature, air temperature, soil temperature, and precipitation data to develop a predictive model of above‐ground activity. The best model for predicting above‐ground activity included an interaction between day of year and current air temperature. Earlier in spring and later in fall, above‐ground activity is more likely at higher air temperatures compared to later in spring and earlier in fall when the same likelihood of above‐ground activity is predicted at lower air temperatures. In spring, we recommend burning in Illinois ornate box turtle habitat before 1 April when air temperature is <10°C and in fall after 1 November when air temperature is <15°C. Above these temperature thresholds, there is a >5% likelihood that turtles in northern populations are above ground. [ABSTRACT FROM AUTHOR]

Herein we briefly provide a background context for and summary overview of the articles comprising this special issue of the Southeastern Naturalist on Macrochelys spp. (alligator snapping turtles). We also make a case for standardization in collecting and reporting morphometric data on these species, clarify the current taxonomic status within the genus, provide updated information on the distribution of Macrochelys in the US, and include a current bibliography and categorical analysis over time of the rapidly growing collection of literature focused on these iconic turtles. [ABSTRACT FROM AUTHOR]

Understanding feeding performance can inform feeding ecology and niche dynamics. Macrochelys temminckii (Alligator Snapping Turtle) and Chelydra serpentina (Common Snapping Turtle) are closely related, sympatric species with documented interactions. To understand ontogenetic and interspecific differences in bite performance, we measured bite force in an ontogenetic series of 62 Alligator Snapping Turtles and 33 Common Snapping Turtles. Within species, bite force positively correlated with size but scaled differently by species. Alligator Snapping Turtles produced higher maximum bite forces overall throughout ontogeny than Common Snapping Turtles, although Alligator Snapping Turtles reach significantly larger maximum sizes than Common Snapping Turtles, thereby enabling them to produce higher maximum bite forces. Differences in bite force between these species provide biomechanical context for distinctions in the ecologies of both species. [ABSTRACT FROM AUTHOR]

Innate immunity provides a fast‐acting and nonspecific defense against microbial infection, and appears to have particular importance in the immune response of ectothermic vertebrates. Chelonians are a globally distributed and diverse group, yet little is known about their basic immune function. The chelonian family Chelydridae is made up of two genera (Chelydra and Macrochelys), represented in our study by the widespread common snapping turtle (Chelydra serpentina; CST) and the southeast USA endemic alligator snapping turtle (Macrochelys temminckii; AST). Our goal was to quantify the innate immune response of the family Chelydridae, using the antibacterial activity of plasma as a measure of immune function. Our results show that the plasma of both species has strong antibacterial properties, but CST plasma kills a higher percentage of bacteria than AST plasma. In addition, while both species showed the highest antibacterial activity at 25 to 30°C, CST plasma retained its antibacterial properties at lower and higher temperatures than AST plasma. Our results indicate that, like many ectotherms, Chelydridae have a relatively strong innate immune response. The stronger, more robust immune response of CSTs compared with ASTs is likely correlated to the differences in geographic ranges but may also have implications for each species' tolerance to anthropogenic habitat degradation and global climate change. Thermal profile of antibacterial activity in common and alligator snapping turtle plasma. HIGHLIGHTS: The plasma of common snapping turtle (CST) and alligator snapping turtle (AST) both exhibit potent, broad‐acting antibacterial activities.The antibacterial activities are rapid, peaking within 20 min of exposure to microbes.The thermal profiles of the antibacterial properties of plasma derived from AST and CST are reflective of their latitudinal distributions.The antibacterial activities are heat labile and inhibited by protease and ethylenediaminetetraacetic acid, which are characteristics of innate immune activity mediated by serum complement. [ABSTRACT FROM AUTHOR]

The article presents distribution records of herpetofauna from state-managed properties in Illinois as of December 2015. These include Ambystoma Texanum or small-mouthed salamander, Pseudacris Crucifer or Spring peeper, Chelydra Serpentina or snapping turtle, and Eumeces Fasciatus or five-lined skink.