Cryptosporidium serpentis Surveillance in Free-Ranging Snakes to Inform a Reintroduction Strategy for the Eastern Indigo Snake (Drymarchon couperi).

Understanding risk factors associated with reintroductions is important for making informed decisions within an adaptive framework. Biosecurity measures minimizing the risk of the introduction or spread of transmissible diseases are a priority when considering the release of captive-reared wildlife. Eastern indigo snake (EIS; Drymarchon couperi) reintroductions have been occurring in Alabama since 2010 and in Florida since 2017. During this effort the pathogen Cryptosporidium serpentis was detected, affecting several of the captive breeding snakes. Infected snakes were quarantined and removed from breeding efforts, which reduced snakes available for the reintroduction projects. To make informed management decisions about future reintroduction strategies, 155 free-ranging snakes were sampled at the two release sites and a third site in Georgia to evaluate the natural occurrence of C. serpentis. Additionally, 72 free-ranging EIS and other species incidentally encountered throughout the EIS range were tested opportunistically. All snakes sampled at the three focal sites tested negative, but one opportunistically tested EIS from South Florida tested positive. These results indicate that C. serpentis is present in the environment in at least one location, but at low levels. Our results suggest that, pending additional surveillance, C. serpentispositive snakes should not be included in reintroduction efforts, and that maintaining a high level of biosecurity is important in captive breeding programs.

Leaf litterbag sampling for larval plethodontid salamander populations in Georgia.

Survey techniques for larval salamanders vary in their effectiveness and efficiencies. In this study, the leaf litterbag sampling technique was employed to gather data on larval salamander populations in perennial streams of southern Georgia. Salamanders were collected monthly for 12 months to analyze capture counts and population size-class structure. Simultaneous dipnet sweep data were used to examine potential count data biases of the leaf litterbag sampling technique. In both leaf litterbag and dipnet sweep surveys, adult and larval Southern Two-lined Salamanders (Eurycea cirrigera) and larval Southern Red Salamanders (Pseudotriton ruber) were sampled. In leaf litterbags, larval E. cirrigera were captured most frequently, followed by adult E. cirrigera and larval P. ruber, respectively. However, the efficiency of collecting adult E. cirrigera and larval P. ruber could not be determined because of small sample sizes. Larval E. cirrigera counts detected from leaf litterbags were frequently lower than those associated with dipnet sweeps, suggesting that the former may underestimate larval salamander counts. Leaf litterbags successfully detected all E. cirrigera size-classes (i.e., first-year, second-year, and adult), further indicating that larvae in Georgia spend 2 years in the aquatic phase. Leaf litterbags are an effective method of sampling larval salamanders when used to assess species assemblage and age-class distribution.