Roads can act as barriers to animal movement through mortality during crossing attempts or behavioral avoidance. This barrier effect has negative demographic and genetic consequences that can ultimately result in local or regional extinction. Here we use radio-telemetry data on three terrestrial vertebrates (eastern massasauga Sistrurus catenatus, eastern box turtle Terrapene carolina and ornate box turtle Terrapene ornata) to test whether roads acted as barriers to movement. Specifically, we test whether individuals avoided crossing roads by comparing the number of observed crossings with the number of road crossings predicted by randomizations of individual movement paths. All species crossed roads significantly less often than predicted by chance, indicating strong road avoidance. Results of this study showing behavioral avoidance and previous studies on road mortality indicate that roads are strong barriers to these species. High mortality during crossing attempts would select for road avoidance, reducing the number of individuals killed on roads over time but leading to genetically partitioned subpopulations due to a lack of gene flow. In species that are long-lived and latematuring, negative genetic effects might not be observable over short time-scales, thus placing populations at high risk of extinction because of a failure to detect an incrementally worsening problem. Formulating successful management strategies for many species in decline will require integrating data on road mortality, animal behavior and population genetics in order to understand more clearly the barrier effect of roads.

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Snake fungal disease (SFD) is a clinical syndrome associated with dermatitis, myositis, osteomyelitis, and pneumonia in several species of free-ranging snakes in the US. The causative agent has been suggested as Ophidiomyces ophiodiicola, but other agents may contribute to the syndrome and the pathogenesis is not understood. To understand the role of O. ophiodiicola in SFD, a cottonmouth snake model of SFD was designed. Five cottonmouths (Agkistrodon piscivorous) were experimentally challenged by nasolabial pit inoculation with a pure culture of O. ophiodiicola. Development of skin lesions or facial swelling at the site of inoculation was observed in all snakes. Twice weekly swabs of the inoculation site revealed variable presence of O. ophiodiicola DNA by qPCR in all five inoculated snakes for 3 to 58 days post-inoculation; nasolabial flushes were not a useful sampling method for detection. Inoculated snakes had a 40% mortality rate. All inoculated snakes had microscopic lesions unilaterally on the side of the swabbed nasolabial pit, including erosions to ulcerations and heterophilic dermatitis. All signs were consistent with SFD; however, the severity of lesions varied in individual snakes, and fungal hyphae were only observed in 3 of 5 inoculated snakes. These three snakes correlated with post-mortem tissue qPCR evidence of O. ophiodiicola. The findings of this study conclude that O. ophiodiicola inoculation in a cottonmouth snake model leads to disease similar to SFD, although lesion severity and the fungal load are quite variable within the model. Future studies may utilize this model to further understand the pathogenesis of this disease and develop management strategies that mitigate disease effects, but investigation of other models with less variability may be warranted.

Disturbances often help structure ecological communities, and their impacts may have consequences on population dynamics and long-term species persistence. Should disturbances affect resources, a trade-off may result between reproduction and individual growth, which in turn could affect the timing of sexual maturity in animals dependent on reaching a requisite size for the onset of maturation. We used a 14-year mark-recapture dataset to determine the effects of catastrophic storms and the removal of nonindigenous vegetation on individual growth rates of a longlived turtle Terrapene carolina bauri. Adult male growth rates increased 19% after the disturbances, whereas female growth rates decreased by a similar percentage. Juvenile growth rates briefly increased, but as these animals became subadults, their growth rates slowed after disturbance, a change more pronounced in females than males. After the disturbances, the onset of male sexual maturity decreased by c. 1 years (from 10.8 to 9.5 years), female maturity was delayed by 2.5 years (from 8.5 to 11.0 years), and the subadult life stage was extended from 2 to 3.5 years. With resources and habitats similarly available to adults, we hypothesize that adult females diverted resources from growth to reproduction, whereas males allocated available resources to growth. Subadult growth rates decreased regardless of sex, implying that fewer or lower quality prey were available to smaller sized turtles in the years following disturbance. The results of this study suggest that habitat disturbances affected individual growth rates differently according to sex and life stage, which in turn affected the timing of maturation. In long-lived vertebrates, such perturbations on life-history traits such as growth rates likely affect population recovery, and may help to explain why turtle populations recover slowly following catastrophic disturbance, even when adult survivability is high.