NORTH-WESTERN JOURNAL OF ZOOLOGY 8 (2): 409-413 ©NwjZ, Oradea, Romania, 2012
Article No.: 121401 http://biozoojournals.3x.ro/nwjz/index.html
IENE 2010 International Conference on Ecology and Transportation
"Improving Connections in a Changing Environment"
September 27 - October 1, Velence, Hungary
A tool to prioritize high-risk road mortality locations
for wetland-forest herpetofauna in southern Ontario, Canada
Kari E. GUNSON
1,
*, Dave IRELAND
2
and Fred SCHUELER
3
1. Corresponding author: Eco-Kare International, 644 Bethune Street, Peterborough, Ontario,
K9H 4A3, Canada / email: kegunson@eco-kare.com
2. Royal Ontario Museum/Ontario Road Ecology Group, 100 Queen’s Park Toronto,
Ontario, M5S 2C6, Canada / email: davei@rom.on.ca
3. Bishops Mills Natural History Centre/Ontario Road Ecology Group, 6 St Lawrence Street,
Bishops Mills, R.R. #2, Oxford Station, Ontario, K0G 1T0, Canada / email: bckcdb@istar.ca
* Corresponding author’s e-mail: kegunson@eco-kare.com
Received: 18. September 2011 / Accepted: 18. February 2012 / Available online: 26. May 2012 / Printed: December 2012
Abstract. Roads are more frequently fragmenting natural habitats increasing the likelihood of collisions
between wildlife and vehicles. The Canada Species at Risk Act (2002) lists species that are threatened with
regional extinction, and roads have been identified as a significant threat for many of these wildlife species in
Ontario, e.g. turtles. In response to negative road impacts on wildlife, we developed a GIS modeling tool that
predicts high-risk road mortality locations for selected wetland-forest herpetofaunal species that are
representative of the landscape. We obtained a habitat suitability index (sum of weighted habitat scores)
within a 12.6 hectare buffer surrounding each 15 x 15 m pixel of road in the landscape. Validation of the final
model with dead and alive on-road herpetofaunal data showed animals were more at risk of road mortality
when roads bisected large areas of wetland-forest habitat. The tool has been effective to promote proactive
mitigation planning within government transportation agencies at the municipal and provincial level. Future
work will develop species-specific models that identify road mortality locations along roads that re-connect
habitat from a local and metapopulation perspective. In addition, the models will be used to prioritize
locations along roads for effective mitigation solutions, e.g. turtle crossing signs and wildlife crossing
structures.
Keywords: Ontario, herpetofauna, Geographic Information System tool, mitigation, prioritize, landscape.
Introduction
In southern Ontario the total length of major roads
has increased fivefold between 1935 and 1995
(Fenech et al. 2005) and there is no point (exclud-
ing large lakes and protected areas) that is more
than 1.5 km from a road. Along with an increasing
road network and associated traffic volumes,
southern Ontario harbours the highest biodiver-
sity of plants and animals in Canada.
As more and more species become threatened
by human activities they are added to the Species
at Risk (SAR) list in Canada by the Committee of
the Status of Endangered Wildlife in Canada. A
SAR is any naturally occurring plant or animal in
danger of extinction or of disappearing from a re-
gion. As of January 2007, there were 534 SAR in
Canada and Ontario is home to 182 of these spe-
cies, the highest percentage of species at risk
among the provinces (Environment Canada 2007).
Today, the negative impacts of roads are widely
seen as a contributing factor leading to SAR des-
ignation. For example, seven of Ontario’s eight
turtle species are listed as SAR and roads have
been identified as one of the most significant
threats for five of these species (Seburn 2007).
For motorists, the most obvious impact of
roads on biodiversity is a direct collision with an
animal crossing or moving along roads. Less obvi-
ous, but significant nonetheless, are the effects of
landscape fragmentation as roads bisect remaining
patches of natural habitat (Trombulak & Frissell
2000). A fragmented landscape caused by roads
has increasingly been a major concern for decreas-
ing species richness, genetic diversity, and species
abundance in Ontario and elsewhere (Fahrig et al.
1995, Findlay & Houlahan 1997, Vos & Chardon
1998, Eigenbrod et al. 2008).
Studies that have evaluated the spatial distri-
bution of road-kill along roads have demonstrated
that they are not random occurrences but spatially
clustered for large mammals and small-vertebrate
fauna (Clevenger et al. 2003, Mountrakis &
Gunson 2009). These spatially clustered hotspots