Thesis (M.S.)--Carleton University, 1997. / Includes bibliographical references (leaves 110-123).

Thesis (Ph.D.)--York University, 2008. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 203-228). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR39026

Peatland ecosystems in the eastern Georgian Bay, Ontario, region often provide overwintering habitat for the eastern massasauga rattlesnake (Sistrurus c. catenatus), a species considered at-risk across its range. Suitable overwintering habitat requires a resilience zone with peat temperatures above 0°C and a water table position sufficient to provide moisture without risk of flooding and these ecohydrological conditions commonly occur in raised peatland microforms (hummocks). Due to a changing climate, these peatlands are at risk of increased wildfire frequency and burn severity which may threaten overwintering habitat availability and suitability. In 2018, a wildfire burned over 11,000 ha of the eastern Georgian Bay landscape which serves as critical habitat for the massasauga. We monitored water table position, snow depth, rainfall, and peat thermal dynamics in hummocks in three burned and three unburned peatlands to assess the potential impacts of wildfire on massasauga overwintering habitat. We found that hummocks were able to provide unfrozen and unflooded habitat regardless of peat burn severity and that surface complexity and peatland-scale characteristics provided the greatest control on microhabitat suitability. This research highlights the importance of conserving peatland ecosystems that provide resilient species at risk habitat. / Thesis / Master of Science (MSc) / The eastern massasauga rattlesnake is a species at risk native to Ontario and parts of the USA. In the eastern Georgian Bay region, massasaugas overwinter in wetlands for up to half the year. This is a sensitive period because flooding or freezing within the hibernacula can be fatal. Due in part to climate change, wetlands in this region are at increased wildfire risk which may threaten the quality of massasauga overwintering habitat. In 2018, a wildfire burned over 11,000 ha of land along eastern Georgian Bay, some of which was massasauga habitat. We monitored the water table position and soil temperature in potential massasauga overwintering habitat to assess its quality after wildfire. We found that wetlands provide unflooded and unfrozen habitat even when burned, and that wetland surface complexity is likely an important regulator of overwintering habitat quality. This research highlights the importance of identifying and protecting wetland ecosystems that provide resilient habitat in the face of a disturbance.

Thesis (M.S.)--Michigan State University. Dept. of Fisheries and Wildlife, 2006. / Title from PDF t.p. (viewed on Nov. 20, 2008) Includes bibliographical references (p. 118-124). Also issued in print.

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Utilizing environmental DNA (eDNA) for the detection of species in the field is a potentially cost-effective and time-saving technology that may be useful in understanding the distribution and abundance of threatened or endangered species such as the Eastern Massasauga (Sistrurus catenatus). I describe the development of an eDNA assay for the species and evaluate its ability to detect eDNA in laboratory and field conditions. In the field samples, I also investigated the potential for abiotic conditions to influence eDNA detection. Species-specific primers and probe were designed to amplify a 152 bp segment of the massasauga COI gene. Target eDNA could be detected in samples containing as little as 100 copies of target DNA/μL. Water samples collected from laboratory housed snakes indicated that eDNA can be detected in water 56 days after massasauga removal. Field samples were taken from crayfish burrows, known overwintering habitat for the species, from four sites that vary in snake use as ascertained by traditional visual surveys. Of the 60 burrows sampled, seven had a positive detection for massasauga eDNA with no difference in detection rate between DNA extracted from burrow water and burrow sediment. Occupancy models fitted to burrow water indicated that larger amounts of total DNA in a sample may increase the probability of detection of a massasauga eDNA. Large confidence intervals in site occupancy (ѱ) and burrow detection (Θ) values suggest that a larger sample size is needed for more reliable occupancy models. Abiotic conditions within crayfish burrows varied among sites but correlation with eDNA detection was not supported. Estimates of qPCR detection within a burrow with eDNA (ρ) suggest that up to 10 qPCR replicates per burrow sample may be necessary. Further studies need to examine eDNA degradation in the field, improve upon the limit of detection, and sample a larger number of sites for eDNA sampling to be a stand-alone survey method for Eastern Massasaugas.

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