Environmental Management
In todays world there is no doubt that our human populations and their activities have an effect on surrounding wildlife
populations. One major topic worthy of discussion is the impact that roads have on wildlife. This is the topic I have
chosen for this weeks forum assignment.
The article I read about this topic was Roads and Wildlife: A Study of the Effects of Roads on Mammals in Roadside
Habitats by Jackie Underhill. The article pointed out concerns with the impact that roads can have on surrounding
wildlife, including but not limited to: habitat loss, habitat fragmentation, habitat degradation, altered community
structures, and traffic fatalities. A study was done that investigated the effects of roads on both large and small mammal
populations.
Roads in their very existence cause a habitat to become fragmented. The habitat fragmentation results in a loss of habitat
and isolation of the remaining habitat. According to Underhill, roads are the fragmenting feature there are additional
effects that include the impacts of pollutants, noise, mortality and the barrier effect of an inhospitable linear terrain
of indeterminate length (Underhill, 2002).
In addition to causing habitat fragmentation, roads also create barriers. These barriers make species to species
interchanges difficult, if not nearly impossible. If members of a species cannot interact with other members of that same
species, their existence may be threatened. Underhill states, Small and isolated populations are vulnerable to extinction
in heterogeneous landscapes because of inbreeding depression or as a result of stochastic events (Underhill, 2002).
Sometimes, it is actually beneficial to the animal populations helping the species to re-colonize new areas. Most often,
however, the habitat fragmentation reduces the habitat quality and subsequently its population size.
The third impact of roads on wildlife that this article explored was that of wildlife fatalities on roadways. Accurate
records of mortality rates on all species are difficult to obtain. Underhill reports that some countries maintain a
national database for fauna casualties on roads but the records are usually for a limited number of larger species.
Although accurate records on wildlife fatalities on roads is hard to obtain, the data scientists do have show that traffic
fatalities contribute a significant amount to the death toll among varying species and Underhill says that on an
international scale, roads and traffic are a major cause of death to both large and medium-sized animals mammals; no
similar estimates exist for small mammal species (Underhill, 2002).
I enjoyed reading this article. It gave the various reasons that roads impact wildlife populations. When I think of roads
and wildlife, I immediately envision the animals that are struck and killed by vehicles. This article pointed out that
while yes, fatalities as a result of vehicle collisions, habitat fragmentation and barriers that roads form to wildlife
populations can also have significant impacts. To reduce the population fragmentation and reduce roadway fatalities there
would need to be a system in place where wildlife populations can move to each side of the roadways unencumbered
(Underhill, 2002). For some areas underground tunnels have be proposed as a solution. While I understand this would be a
huge expense to alter existing roads, it is something that should be included in all new roads and existing major roads. We
will continue to have roads and with increasing urban sprawl it is important to find solutions to the impacts on wildlife
that were presented in this article.