Acute physiological response by the plethodontid salamander Eurycea cirrigera (Southern Two-lined Salamander) to predation stress from alarm chemicals and predator kairomones

Plethodontid salamanders may reduce predation risk via behavioral responses to predator kairomones and alarm chemicals from injured salamanders. However, it not known whether such predator cues prompt acute physiological responses, which may enhance arousal and the physical ability to escape from a predator. I examined whether predator chemical cues elicit an acute cardiac response in Eurycea cirrigera (Green, 1831) (Southern Two-lined Salamander). I compared heart rates before and after exposure to the odor of the large predatory Pseudotriton ruber (Sonnini de Manoncourt and Latreille, 1801) (Red Salamander) and exposure to alarm chemicals from homogenized skin of conspecifics. For two controls, I compared heart rates before and after exposure to the odor of live conspecifics and the odor of the large non-predatory Plethodon mississippi Highton in Highton, Maha and Maxson, 1989 (Mississippi Slimy Salamander). Compared with resting values, heart rates significantly increased in response to predator kairomones (mean rate increased 10.9% after 2 min and 12.7% after 5 min) and alarm chemicals from conspecifics (mean rate increased 12.0% after 2 min and 14.5% after 5 min). In contrast, heart rates after exposure to each control odor did not significantly differ from resting values. Results demonstrate an acute cardiac response to chemical cues indicative of either a predator or a predation event.

UPDATED GEOGRAPHIC DISTRIBUTIONS OF MICHIGAN HERPETOFAUNA:

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.

Current distribution and status of amphibians and reptiles in Will County, Illinois

The distribution of amphibians and reptiles in Will County, Illinois, was assessed using museum records and results from 58 surveys conducted between 1986 and 2009 on lands owned and managed by the Forest Preserve District of Will County (FPDWC) and Illinois Department of Natural Resources (IDNR). One hundred and twenty sources of information were examined including technical reports, theses, dissertations, and personal data belonging to the authors. Forty-eight species (19 amphibians, 29 reptiles) were documented by photos or specimens from Will County. Eleven species were determined widespread and common, 6 were categorized as patchy distributions and are uncommon or locally common, and 23 were found to have restricted distributions and are considered rare, including seven state-listed species. One of those state-listed species (Sistrurus catenatus) is likely extirpated. Eight species had undetermined distributions, four of them of questionable occurrence. One of the questionable species (Anaxyrus fowleri) is no longer included in the current list of Will County herpetofauna because it has been determined to have been an introduction and no known population exists. For three others Terrapene carolina, Pantherophis spiloides, Nerodia rhombifer) we were unable to conclusively interpret their records and they are assigned questionable status until further records confirm existence of viable, self sustaining populations. Of seven state-listed species (four threatened, three endangered), one may be extirpated (Sistrurus catenatus). Lithobates sylvaticus, Hemidactylium scutatum, Ambystoma texanum, and Eurycea cirrigera are glacial relicts that are highly vulnerable to extirpation due to pollution, isolation, and a warming climate. Presently, 43 species (18 amphibians, 25 reptiles) are known to occur in Will County, making it the most species-rich county in the Chicago region.