Habitat Use and Road Mortality of Amphibians and Reptiles in Southwestern Manitoba, a Master of Science Thesis Defense by Alyssa Eagle, MSc. Environmental & Life Sciences Candidate.

All are welcome to attend. Light refreshments will be provided.

• Advisor: Dr. Pamela Rutherford
• Committee Members: Dr. Chris Malcolm, Dr. Dion Wiseman

Abstract

The purpose of my research was to examine amphibian and reptile species’ abundances and distributions, with a broader goal of contributing information to mitigation planning to conserve wetland ecosystems within the Prairie Pothole Region of southwestern Manitoba. My main objectives were to 1) determine species’ composition, abundance, and distribution in roadside wetlands, 2) determine which habitat factors affect abundance, distribution, and species’ composition, 3) assess the impacts of roads on amphibians and reptiles by studying road mortality on different road surfaces, and 4) recommend management and conservation strategies.

I surveyed thirty roadside ponds in southwestern Manitoba nearest the towns of Waskada and Coulter for seven amphibian species. I used a combination of visual, auditory, dip net, and funnel trapping methods to determine abundance and distribution across three road segments. I collected habitat data and measured water chemistry (pH, salinity, total dissolved solids, and conductivity) to determine relationships between occurrence and habitat variables. Conductivity, total dissolved solids, and land use were the most influential factors in occurrence. Hotspot analysis revealed two locations of high amphibian activity.

Roadkill data was collected from 2015 to 2017 including seven amphibian species and five reptile species. Pedestrian surveys along four roads including two paved and two gravel determined locations and magnitudes of roadkills. Reptiles had the most roadkills overall. Roadkill decreased among years but didn’t change seasonally. Paved roads had more roadkill than gravel roads. Hotspot analysis revealed two locations with high mortality but these did not correspond to areas with high occurrence.

Further research is needed to determine more hotspots and areas that require mitigation. Potential strategies include signage and reduced speed zones, seasonal drift fencing with pitfall traps, and ecopassages.