when animal populations are at risk from roads: an interactive model of road
Jaeger, J.A.G., Bowman, J., Brennan, J., Fahrig, L., Bert, D.,
Bouchard, J., Charbonneau, N., Frank, K., Gruber, B., and K. Tluk von
in press (2005).
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
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
populations are those with high car avoidance
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.
traffic volume has a larger effect than
road size on the impact of
on population persistence.
potential application of our model
run the model on the web or to download it go to
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.
avoidance behaviour, barrier effect, car avoidance, habitat fragmentation,
habitat loss, noise avoidance, roads, road avoidance, road crossings, road
effects, traffic, traffic mortality