Photo: Ryan Wolfe

Blue racers: they’re stunningly beautiful, uniquely fast, and sadly, are one of the most endangered species of snakes in Canada. Once found in several locations of southwestern Ontario, this species’ range in Canada is now restricted solely to Pelee Island in the western basin of Lake Erie.

We have discussed what is involved in updating the population estimate for blue racers on Pelee Island (The plight of Canada’s only remaining population of blue racer / Slow spring, fast snakes: An update on blue racer spring surveys / Day in the life of a blue racer snake researcher). However, the population estimate is just one aspect of a large, collaborative, multi-year project working to conserve the remaining blue racer population on Pelee Island. So, in a series of blog posts, we’ll be talking about some of the other conservation work that is a part of the project, all with the goal of preventing further declines in the blue racer population and improving our knowledge of the species.

In this article, our focus is on blue racer habitat.

Blue racers prefer open to semi-open habitats with plenty of cover, such as alvars, grasslands, and open woodlands. In southern Ontario, most of this habitat has been converted for human use, which has led to the extirpation of blue racers from the mainland. Fortunately, almost 20% of Pelee Island is protected as conservation land, encompassing much of the blue racer’s known distribution. However, these open habitats are threatened by the encroachment of successional woody plants, such as (gray) dogwood, prickly ash, staghorn sumac, and the invasive multiflora rose. Not only can these species outcompete others for resources, but encroachment can also lead to increases in canopy cover and alterations to the specific habitat requirements of blue racer and their prey.

To restore open habitats, multiple management efforts have taken place within conservation lands on Pelee Island, including a low-intensity prescribed burn and annual mechanical removal of targeted woody vegetation using brush saws and loppers. Both management techniques were carried out with the goals of reducing encroachment by woody shrubs and benefiting the native species of vegetation that are adapted to and require disturbance to flourish.

Both prescribed burns and mechanical vegetation removal are common techniques to control succession and restore open-canopied habitats, but how blue racers and other species at risk respond to these actions remains unknown. To address this knowledge gap, ongoing research has been underway by the University of Toronto, Ontario Nature, Scales Nature Park, NRSI Inc., the University of Rennes, Trent University, 8 Trees Inc., and Nature Conservancy Canada to compare open habitats on Pelee Island that experienced fire, mechanical vegetation removal, and control sites that experienced no restoration actions. Ongoing monitoring at each site consists of:

  • Characterizing habitat conditions at each site to determine suitability for blue racers, such as environmental temperatures, canopy cover, and the type and amount of surrounding vegetation.
  • Annual small mammal trapping to estimate their abundance. This will shed light on how restoration practices may impact prey availability for blue racers.
  • Snake surveys. The number of snakes observed at each site will provide insight on potential changes in blue racer habitat selection.

The data collected from monitoring efforts throughout the project will be analyzed and used to evaluate the efficacy of prescribed burn and mechanical removal techniques at restoring and maintaining high quality blue racer habitat. The results of this research and continued monitoring efforts will be compiled into an evidence-based best management practices (BMP) document to help guide habitat management efforts to best support the remaining blue racer population in Canada!

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