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Road Model
This is a model
of road avoidance behavior of animals at roads to predict when
animal populations are at risk from roads.
Description:
Roads and
traffic affect animal populations detrimentally
in four ways: they decrease habitat amount and quality, enhance
mortality due to collisions with vehicles, prevent access to resources
on the other side of the road, and subdivide animal populations into
smaller and more vulnerable fractions. Roads will affect persistence of
animal populations differently depending on (1) road avoidance behavior
of the animals (i.e., noise avoidance, road surface avoidance, and car
avoidance), (2) population sensitivity to the four road effects, (3)
road size, and (4) traffic volume. We have created a model based on
these population and road characteristics to study the questions: (1)
what types of road avoidance behaviors make populations more vulnerable
to roads?; (2) what types of roads have the greatest impact on
population persistence?; and (3) how much does the impact of roads vary
with the relative population sensitivity to the four road effects?
Our results
suggest that, in general, the most vulnerable
populations are those with high noise and high road surface avoidance,
and secondly, those with high noise avoidance only. Conversely, the
least vulnerable populations are those with high car avoidance only, and
secondly, high road surface and high car avoidance. Populations
with low overall road avoidance and those
with high overall road avoidance tend to respond in opposite ways when
the sensitivity to the four road effects is varied. The same is true of
populations with high road surface avoidance when compared to those
with high car and high noise avoidance. The model
further predicted that traffic volume has a larger effect than road
size on the impact of roads on
population persistence. One
potential application of our model (to run the model on the web or to download it go to www.glel.carleton.ca/ or
www.nls.ethz.ch/roadmodel/index.htm or contact the first author) is to
generate predictions for more structured field studies of road
avoidance behavior and its influence on persistence of wildlife
populations.
Published
in: Predicting when animal populations are at risk from roads: an
interactive model of road avoidance behavior
by Jaeger,
J.A.G., Bowman, J., Brennan, J., Fahrig, L., Bert, D., Bouchard, J.,
Charbonneau, N., Frank, K., Gruber, B., and K. Tluk von Toschanowitz
Ecological
Modelling (2005), in press.
Keywords: avoidance
behaviour, barrier effect, car avoidance, habitat fragmentation,
habitat loss, noise avoidance, roads, road avoidance, road crossings,
road effects, traffic, traffic mortality
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