Crossings and Connectivity: How TRCA’s Road Ecology Work Helps Native Species

Brake for Snakes road sign

Why did the turtle cross the road? Or the frog, the salamander or the snake? Or any wildlife for that matter?

To get to the other side, of course!

Many regional reptiles and amphibians actively move between forests and wetlands at different times of year for breeding, foraging or hibernation. In fact, the word amphibian actually comes from the Greek amphibios, which means “double life”, because most amphibians live part of their life on land and part in the water.

This need to access a variety of habitat types forces these species out onto the road — and therefore into danger.

baby snapping turtle on side of road
A baby snapping turtle makes its way across the edge of a busy road. Snapping turtles spend most of their lives in water, but during the breeding season (early to mid-summer) females travel overland in search of a suitable nesting site in gravel or sandy areas. Nests are often built along the gravel shoulder of roads, making this sensitive species susceptible to vehicle collisions.

Roads lead to increased mortality for native amphibian and reptile species, the majority of which are designated as Regional Species of Conservation Concern within the jurisdiction of Toronto and Region Conservation Authority (TRCA). Roads also reduce habitat size and sever the connections between forests and wetlands, which limits the ability of species to access resources and leads to population isolation.

Toronto and region is expected to continue urbanizing as the population grows over the next decade. This growth will mean further construction, expansion and upgrading of roadways and railways. Most of this infrastructure crosses or will cross one or more of the region’s valley and stream corridors, requiring construction of bridges and culverts. This anticipated increase in road density is considered one of the greatest threats impacting regional wildlife populations.

TRCA’s work in the area of road ecology is all about addressing these issues. Preserving or enhancing habitat connectivity – that is, enabling species to travel between different habitats – is one of the keys to healthy biodiversity.

Amphibians, such as these endangered Jefferson salamanders, travel from upland wintering quarters in deciduous forests to their wetland breeding sites. The journeys can be dangerous as they cross busy roads.

Road Ecology Surveys

Since 2015, TRCA has collaborated with the Regions of York and Peel, and partners Credit Valley Conservation, Ontario Road Ecology Group (OREG) and Eco-Kare, to collect thousands of baseline road ecology data points at over 25 valley and stream corridor locations.

These locations were predetermined to be possible amphibian movement hotspots based on a habitat modelling exercise. TRCA monitoring staff record live sightings of wildlife species crossing the road, as well as roadkill.

The aim of these baseline road ecology studies is to confirm which areas have a high incidence of amphibian road mortality. Identifying priority areas for habitat connectivity helps to guide the development of appropriate mitigation measures — such as wildlife crossing structures, fencing and road signage — and/or habitat creation or restoration projects.

One of the monitoring sites (as shown in the video below) is at Heart Lake Road, a known road-mortality hotspot where TRCA, in partnership with OREG and City of Brampton, is already taking measures to plan for enhanced wildlife connectivity.

Working in partnership with City of Brampton, TRCA has installed a dedicated wildlife culvert under Heart Lake Road to allow safe passage for wildlife as part of the long-term road ecology study.

To facilitate access to this passage, directional wildlife fencing has also been installed so animals are channeled towards the culvert. Citizen scientists have been instrumental in collecting the data needed to support this initiative.

Beyond initiatives like these, there is still a need for dedicated long-term road ecology research and monitoring, across TRCA’s jurisdiction, to ensure that the right data is collected prior to any construction through locations critical for habitat connectivity, so that we can determine the best ways to mitigate impact on wildlife.

It will also be important to implement a long-term monitoring program post-construction to make sure that mitigation measures are creating the desired improvements.

More About TRCA’s Role in Road Ecology

This road ecology research and monitoring helps to support the implementation of TRCA’s Crossings Guideline for Valley and Stream Corridors.  These guidelines, in turn, inform partner municipalities and the private sector on where and how to mitigate the impact of roadways on habitat connectivity.

This work also advances TRCA’s ecosystem management objectives related to the implementation of our Natural Heritage System Strategy. The value of protecting and restoring terrestrial and aquatic natural heritage functions is particularly significant in Toronto and region, where valley and stream corridors comprise the bulk of the remaining natural system.

In addition, road ecology data adds to the biodiversity knowledge gained through several environmental monitoring initiatives TRCA has been involved with over the years, including the Regional Watershed Monitoring Program and the Terrestrial Long-Term Monitoring Program. Currently, TRCA monitors plants and animals in forests, wetlands and meadows across our regional watersheds by conducting biological inventories and assessments and surveying long-term fixed plots.

All of this information combined helps to guide future decision-making with respect to restoration activities, environmental protection and the management of natural areas.

TRCA also works collaboratively with academic partners — such as Ryerson University and University of Toronto, supported by public and private grants — to advance the science and practice of road ecology throughout Toronto and region. Their expertise is helping us to gain deeper understanding about road ecology and habitat connectivity and modelling, and will contribute to future land-use site planning and design.

What Can You Do to Help?


Monitoring Matters! Through scientific data collection, TRCA tells the stories about the changes affecting the natural areas and watercourses within our regions. For more information, please visit the monitoring webpage, follow @TRCA_Monitoring on Twitter, subscribe to the Monitoring Matters e-newsletter, or check out the YouTube playlist.