Ecology of the Squirrel Treefrog (Hyla squirella) in Southern Arkansas

We conducted an ecological study of the Squirrel Treefrog, Hyla squirella near El Dorado, Union Co., Arkansas from May-Oct. 2013. We extended the known distribution by ~2 km and documented the first breeding occurring on 28 May and the first transformation of juveniles on 27 Aug. Three endoparasites were documented: Opalina sp., Nyctotherus cordiformis, and Physaloptera sp. larvae. We also provide information on endoparasites of Florida H. squirella as well as a summary of helminths of this frog

THE ART OF WAR: PATTERNS AND MECHANISMS UNDERLYING PREDATOR-INDUCED PLASTICITY OF AMPHIBIANS

Organisms often employ phenotypic plasticity as a strategy to cope with variable environments. This is particularly true of predation threats, wherein prey induce defenses to reduce detection or capture by predators. In order to produce appropriate defenses, prey must be able to discern useful information from environmental cues. Despite the pervasive production of inducible defenses, we understand very little of how much useful information is conveyed to organisms in cues, or how the subsequent plastic responses vary within groups of organisms. To address the need for comparative studies of phenotypic plasticity, we sought to examine morphological and behavioral defenses of five species of Ambystoma salamander larvae in response to larval dragonfly (Anax junius) chemical cues in a common garden environment. Dragonfly cues induced relatively few morphological changes across species. Likewise, salamanders did not vary in their refuge use during the experiment, though several species reduced their activity in the presence of predators early in development. Our results suggest that behavioral and morphological defenses in Ambystoma are highly variable among species and the genus appears to be less plastic than tadpoles and other salamander species. To understand what types of information prey are capable of responding to in their environment, we raised grey treefrog tadpoles (Hyla verisciolor) in the presence of cues isolated from different stages of an attack sequence by larval dragonflies (A. junius) or larval dragonflies THE ART OF WAR: PATTERNS AND MECHANISMS UNDERLYING PREDATOR-INDUCED PLASTICITY OF AMPHIBIANS Heather Michelle Shaffery, M.S. University of Pittsburgh, 2013 iv consuming different combinations of grey treefrog tadpoles and snails (Helisoma trivolvis) across different temporal sequences. When exposed to a predator consuming grey treefrogs, tadpoles reduced their activity, increased their hiding behavior, and induced deeper tails. As we exposed prey to more types of cues from an attack sequence, they also increased tail depth and hiding behavior but did not change their activity. Additionally, treefrog tadpoles generally increased their defense as the biomass of treefrogs consumed increased, regardless of whether heterospecifics were being consumed. Our results suggest that treefrogs can gain cue information from all portions of an attack sequence, and that both temporal patterns of feeding and diet content of predators influence the type and magnitude of induced prey defenses

Hyla versicolor-chrysoscelis Species Complex of Gray Treefrogs in Arkansas: Histological and Ultrastructural evidence

We investigated the Hyla versicolor-chrysoscelis species complex (tetraploid and diploid species, respectively) of cryptic gray treefrogs from Arkansas using light and scanning electron microscopy. From previous studies of this treefrog complex in other states, H. versicolor has been shown to exhibit larger nuclear diameters and larger toe pad epithelial cells than H. chrysoscelis. Based upon average nuclear diameters of eyelid epithelial cells, we found two or possibly three groups of frogs. The presumed H. versicolor exhibited greatly enlarged toe pad epithelial cells using scanning electron microscopy and were found in four counties, three of which are in the Ozark Mountains. Hyla chrysoscelis occurs throughout the stat

UPDATED GEOGRAPHIC DISTRIBUTIONS OF MICHIGAN HERPETOFAUNA:: A SYNTHESIS OF OLD AND NEW SOURCES

Recently a comprehensive overview of reptiles and amphibians in Michigan was published. Unfortunately, the distributions of the species represented were compiled before widespread accessibility to technological tools providing greater access to museum and historical records as well as citizen science efforts. To update the known ranges of Michigan herpetofauna, published literature, museum collections, and photographic vouchers submitted to an online database were examined and 339 new county and island records were added, updating the maps for 48 of Michigan’s 55 known species of reptiles and amphibians. I also present the first published list of Michigan amphibians that includes two new plethodontid salamanders, the Northern Dusky Salamander (Desmognathus fuscus) and Southern Two-lined Salamander (Eurycea cirrigera). This paper serves as an example of the wealth of information available to scientists that may have previously been unobtainable, and can be used for the distribution of herpetofauna elsewhere

Effects of prescribed fire on Cope’s Gray Treefrog (Hyla chrysoscelis) across habitat scales and life stages

Fire may alter both aquatic and terrestrial habitat used by all amphibian life stages, yet, our knowledge of its effects on amphibians is primarily limited to adult responses. I present an integrated approach to test the response of Cope’s Gray Treefrog (Hyla chrysoscelis) to fire by examining responses in tadpole performance and survivorship, adult abundance, and oviposition. Tadpoles raised with burned leaf litter had similar survival, but total mass and total length were 440% and 170% greater, respectively, for tadpoles raised in unburned litter. I assessed terrestrial and aquatic oviposition cues by embedding burned and unburned litter treatments within burned and unburned terrestrial plots. Oviposition was an order of magnitude higher in unburned plots, regardless of the litter treatment. This difference was not statistically significant or driven by adult abundance. My results indicate the need to explore the dynamic effects forest management practices can have on amphibians across life stages

Amphibian Contributions to Ecosystem Services

Ecosystems provide essential services for human society, which include provisioning, regulating, cultural, and supporting services. Amphibians provide provisioning services by serving as a food source for some human societies, especially in Southeast Asia. They also serve as models in medical research and provide potential for new pharmaceuticals such as analgesics and anti-viral drugs derived from skin secretions. Amphibians contribute to regulating services by reducing mosquito recruitment from ephemeral wetlands, potentially controlling other pest species, and indirectly through predation of insect pollinators. Often neglected, ecosystems also provide cultural services to human societies that increase the quality of human life through recreation, religion, spirituality, and aesthetics. As an abundant and diverse class of vertebrates, amphibians also play prominent roles in the culture of human societies through pathways such as mythology, literature, and art. Most research on the role of amphibians in ecosystems has been on their contribution to supporting services. This is also the area where amphibians are likely to have the largest contribution to ecosystem services. Supporting services have structural (e.g., habitat) and functional (e.g., ecosystem functions and processes) components. Amphibians can affect ecosystem structure through soil burrowing and aquatic bioturbation and ecosystem functions such as decomposition and nutrient cycling through waste excretion and indirectly through predatory changes in the food web. They also can control primary production in aquatic ecosystems through direct consumption and nutrient cycling. Unfortunately, amphibians are experiencing major declines and humans may be losing associated ecosystem services. It is important to understand how declines affect ecosystem services for human societies, but these declines can also serve as natural experiments to understand the role of amphibians in ecosystems

Toe Tip Morphology in Six Species of Salamanders, genus Ambystoma (Caudata: Ambystomatidae) from Arkansas Using Scanning Electron Microscopy

The toe tip friction surface in six species of Ambystoma (A. annulatum, A.maculatum, A.opacum, A. talpoideum, A. texanum, and A. tigrinum) from Arkansas was examined using scanning electron microscopy. We found no sexual dimorphism in cell surface ultrastructure. Variation within and between species was considerable. The most active burrower, A. tigrinum, possessed the most disorganized cell surface, whereas the least active burrowers (A.annulatum, A.maculatum, and A. opacum) had morphologically similar and relatively smooth toe tips. In A. talpoideum and A. texanum, cell surfaces exhibited microprojections. Only these two species possessed mucous pores in close proximity to the friction surface. The microstructure of cell surfaces transcended species groups in Ambystoma and would not represent a reliable taxonomic tool

Some unusual natural areas in Illinois

Bibliography: p. 42-43