The effects of predators in aquatic ecosystems have been widely examined on the morphology, behavior, and life history of larval prey organisms. The ability of the Mole Salamanders (Family Ambystomatidae) to display phenotypic plasticity in response to environmental factors of has been extensively documented in the attempt to produce greater understanding of their complex larval stage and the general effects of predators on their survival. In this paper, I explored the empirical results of 16 ambystomatid egg predation studies and 121 larval ambystomatid predation studies and then compared them with several prevalent models of predator induced plasticity. A longer time and a larger total size at hatching was found in 75% of the egg predation studies. In the larvae predation studies, 27% found an earlier time and smaller size and 27% found a later time and larger size at metamorphosis. Only 11 of the 121 larvae predation reviewed studies tested both the time and size at metamorphosis. Fewer studies than expected were found to meet the specific predictions of the various models of predation risk on the growth, morphology, and behavior, but many followed the general directionality predicted. Overall however, predation risk caused reduced growth rates, smaller morphological traits, reduced behavior, and reduced survival. Future studies should continue data collection to complete metamorphosis and test larval growth, morphology, and behavior in more realistic experimental designs.

Acknowledgements: We thank J. Alex Baecher for help with sampling and Daniel Douglas for assistance on micro-gastropod identification. We would also like to thank Robert Watts and Curtis Cox for their invaluable knowledge of LCW. Lastly, we would like to thank the Division of Natural Areas (EKU) for field station access and support.

Aim: Population dynamics are often tightly linked to the condition of the landscape. Focusing on a landscape impacted by mountaintop removal coal mining (MTR), we ask the following questions: (1) How does MTR influence vital rates including occupancy , colonization and persistence probabilities, and conditional abundance of stream salamander species and life stages? (2) Do species and life stages respond similar to MTR mining or is there significant variation among species and life stages?

Location: Freshwater and terrestrial habitats in Central Appalachia (Southeastern Kentucky, USA).

Methods: We conducted salamander counts for three consecutive years in 23 headwater stream reaches in forested or previously mined landscapes. We used a hierarchical, N-mixture model with dynamic occupancy to calculate species-and life stage-specific occupancy, colonization and persistence rates, and abundance given occupancy. We examined the coefficients of the hierarchical priors to determine population variation among species and life stages.

Results: Over 3 years, reference sites had greater salamander abundances and were occupied at a much higher rate than streams impacted by MTR. At sites im-pacted by MTR mining, most salamander species and life stages exhibited reduced initial occupancy, colonization rates, persistence rates and conditional abundance relative to reference stream reaches. Furthermore, the rates in MTR sites showed low variance, reinforcing that species and life stages were responding similar to MTR.

Main conclusions: Salamander populations in landscapes modified by MTR mining exhibited significantly reduced vital rates compared to reference sites. Yet, similarity in responses across species suggests that management or restoration may benefit the entire salamander assemblage. For example, reforestation could reduce landscape resistance, repair altered hydrologic regimes and allow for higher rates of colo-nization and persistence in streams impacted by MTR.

In the Central Appalachians (USA), mountaintop-removal mining accompanied by valley fills often leads to streams with elevated specific conductivity (SC). Thus, the ionic composition of fresh waters in this region is hypothesized to be a driver of the distribution and abundance of freshwater taxa, including stream salamanders.We examined the association between SC and stream salamander populations by conducting salamander counts in 30 southeastern Kentucky streams across a continuous gradient of SC that ranged from 30 to 1966lS/cm. Wecounted 2319 salamanders across 5 species and, using a hierarchical Bayesian version of the N-mixture model,found a negative association between SC and salamander occupancy rates. This finding was consistent across adults and larvae of the 5 species we examined. Furthermore, we found that most salamander species and life stages showed reduced abundances given occupancy at greater SC levels. For example, estimated mean abundance given occupancy of larval Southern Two-lined Salamanders (Eurycea cirrigera) was 67.69 (95% credible interval 48.31–98.25) ind/10 m at 250lS/cm and 2.30 (95% credible interval 1.46–3.93) ind/10 m at 2000lS/cm. The consistent negative association across all species and life stages supports the hypothesis that salamander distributions and abundances are negatively associated with elevated SC of streams in southeastern Kentucky, even though physical and chemical environmental attributes, such as forest cover within stream catchments, were correlated with SC.Restoration of streams affected by mountaintop-removal mining should focus on restoring the ionic compositions that naturally occur in this region.

Changes in land use, such as mountaintop removal mining with valley fills (MTR-VF), often results in headwater streams with elevated specific conductivity (SC). Stream salamanders appear to be particularly sensitive to elevated SC, as previous studies have shown occupancy and abundance decline consistently among all species and life stages as SC increases. Yet, the proximate mechanism responsible for the population declines in streams with elevated SC have eluded researchers. We sampled salamander assemblages across a continuous SC gradient (30-1966 μS/ cm) in southeastern Kentucky and examined the diet of larval and adult salamanders to determine if the ratio of aquatic to terrestrial prey (autochthony), total prey volume, aquatic prey importance (I x), and body condition are influenced by SC. Further, we asked if threshold points for each diet component were present along a gradient of SC. Larval salamanders experienced a 12-fold decline in autochthony at 153 μS/cm, a 4.2-fold decline in total prey volume at 100 μS/cm, a 2.2fold decline in aquatic I x at 135 μS/cm, and a rapid decline in body condition as SC increased. Adult salamanders experienced a 3-fold decline in autochthony at 382 μS/cm, no change in prey volumes, a 2-fold decline in aquatic I x at 163 μS/cm, and a decline in body condition as SC increased. Our results indicate that SC indirectly affects stream salamander populations by changing the composition of diet, which suggests that food availability is a proximate mechanism that leads to reduced population occupancy, abundance, and persistence in streams with elevated SC.

Is dietary or microhabitat specialization associated with environmental heterogeneity in horned lizards (Phrynosoma)? Ecol. Evol. 9:5542-5550.-, i. t. cliFton, and t. k. VaZqueZ. 2019b. Developmental plasticity of thermal ecology traits in reptiles: trend, potential benefits, and research needs. J. Therm. Biol. 84:74-82. sannolo, M., F. M. barroso, and M. a. carretero. 2018. Physiological differences in preferred temperatures and evaporative water loss rates in two sympatric lacertid species. Zoology 126:58-64. sinerVo, b., F. MéndeZ

CRYPTOBRANCHUS ALLEGANIENSIS ALLEGANIENSIS (Eastern Hellbender). LARVAL PREDATION. Salmonids have been identified as dominant predators of larval amphibians, particularly salamander larvae (Barr and Babbitt 2007. Freshw. Biol. 52:1239-1248). The presence of trout in lakes has been linked to lower survival in Gyrinophilus porphyriticus (Spring Salamander; Resetarits 1995. Oikos 73:188-198) and reduced larval salamander densities for Ambystoma macrodactylum (Long-toed Salamander; Tyler et al. 1998. Conserv. Biol. 12:94-105). In some extreme cases, the presence of Oncorhynchus mykiss (Rainbow Trout) led to nearly zero survival of larval A. macrodactylum (Pearson 2009. Can. J. Zool. 87:948-955). Larval salamanders such as Salamandra salamandra (Fire Salamander) may increase their use of refuge habitat in the presence of Salmo trutta (Brown Trout; Bylak 2018. Can. J. Zool. 96:213-219). Indeed, larval Cryptobranchus alleganiensis bishopi (Ozark Hellbender) can actively retreat into interstitial spaces when disturbed (Pitt et al. 2016. Herpetol. Bull. 138:36-37). However, they may show altered, weak anti-predatory behavioral responses to introduced non-native or naturalized predators such as O. mykiss (Gall 2009. Ethology 116:47-58). On 8 April 2020, angler Austin Hall discovered a partially digested, gilled larval C. a. alleganiensis, inside the stomach contents of an O. mykiss (ca. 30 cm total length) he had caught on private property in Hatchery Supported Trout Waters of the South Toe River, Yancey County, North Carolina, USA (794 m elev.; specific GPS point is withheld but is on file with the North Carolina Wildlife Resources Commission, NCWRC). The NCWRC, as well as private groups, routinely stock trout in this system at numerous bridge and roadside access points throughout the year, and self-sustaining populations of both O. mykiss and S. trutta occupy the river. The NCWRC's most recent stocking event in the South Toe River prior to the date of capture was on 26 March 2020, when an estimated 520 O. mykiss were released along with 10 S. trutta and 1,970 Salvelinus fontinalis (Brook Trout). The closest known upstream and downstream stocking points to this capture are ca. 4.3 and 1.6 km linear stream distance away, respectively. A recent study in western North Carolina found that 71% of radio tagged,

In the Central Appalachians (USA), mountaintop-removal mining accompanied by valley fills often leads to streams with elevated specific conductivity (SC). Thus, the ionic composition of freshwaters in this region is hypothesized to be a driver of the distribution and abundance of freshwater taxa, including stream salamanders. We examined the association between SC and stream salamander populations by conducting salamander counts in 30 southeastern Kentucky streams across a continuous gradient of SC that ranged from 30 to 1966 lS/cm. We counted 2319 salamanders across 5 species and, using a hierarchical Bayesian version of the N-mixture model, found a negative association between SC and salamander occupancy rates. This finding was consistent across adults and larvae of the 5 species we examined. Furthermore, we found that most salamander species and life stages showed reduced abundances given occupancy at greater SC levels. For example, estimated mean abundance given occupancy of larval Southern Two-lined Salamanders (Eurycea cirrigera) was 67.69 (95% credible interval 48.31-98.25) ind/10 m at 250 lS/cm and 2.30 (95% credible interval 1.46-3.93) ind/10 m at 2000 lS/cm. The consistent negative association across all species and life stages supports the hypothesis that salamander distributions and abundances are negatively associated with elevated SC of streams in southeastern Kentucky, even though physical and chemical environmental attributes, such as forest cover within stream catchments, were correlated with SC. Restoration of streams affected by mountaintop-removal mining should focus on restoring the ionic compositions that naturally occur in this region.