How
Do Highways Influence Snake Movement? Behavioral Responses to Roads and
Vehicles
Kimberly M. Andrews and J. Whitfield Gibbons
Savannah River Ecology Laboratory, University of Georgia, Drawer E, Aiken,
South Carolina 29802
Abstract
Roads affect animal survivorship and behavior and thereby can act as a
barrier to movement, which exacerbates habitat fragmentation and disrupts
landscape permeability. Field experiments demonstrated that interspecific
differences in ecology and behavior of snakes affected responses of species
when they encountered and crossed roads. The probability of crossing a
road varied significantly among southeastern U.S. snakes, with smaller
species exhibiting higher levels of road avoidance. Species also differed
significantly in crossing speeds, with venomous snakes crossing more slowly
than nonvenomous ones. All species crossed at a perpendicular angle, minimizing
crossing time. A model incorporating interspecific crossing speeds and
angles revealed that some species cannot successfully cross highways with
high traffic densities. Individuals of three species immobilized in response
to a passing vehicle, a behavior that would further prolong crossing time
and magnify susceptibility to road mortality. Identifying direct and indirect
effects of roads on snakes is essential for mitigating road impacts and
for designing effective transportation systems in the future.
(KMA)
E-mail: andrews@srel.edu; and (JWG) E-mail: gibbons@srel.edu.
Send reprint requests to KMA.
SREL Reprint #2906
Andrews, K.
M. and J. W. Gibbons. 2005. How Do Highways Influence Snake Movement?
Behavioral Responses to Roads and Vehicles. Copeia 4:772-782.
