THE IMPACT OF TRAFFIC FATALITIES ON LAVA LIZARD POPULATIONS (Microlophus albemarlensis) IN SANTA CRUZ, GALAPAGOS
TANNER, DAWN; Perry, James A. Conservation Biology Graduate Program, University of Minnesota, 200 Hodson Hall, 1980 Folwell Avenue, St. Paul, Minnesota, 55108-6124, USA, tann0042((AT))umn.edu.
Vehicle collisions with wildlife impact species everywhere that roads divide and transect natural habitats. This study addresses the impact of traffic fatalities on lava lizards, Microlophus albemarlensis, on the island of Santa Cruz, Galapagos.
The main road bisecting the island north to south was a new addition to the island, begun in 1974 but not completed with asphalt until 2000. We assessed impacts occurring due to an increase in traffic and speed of travel on the island.
Using Poisson Regression to analyse transect data at incremental positions from the road, we found a 30% increase in lizard abundance per 100 metres distant from the road, with significant results also between natural vegetation zones with little human impact and highly impacted areas with invasive species. By travelling the length of the 40-kilometre road, we were able to identify hot spots for fatalities, which will be used to target areas for future management efforts.
We used incidence of tail loss to quantify additional energetic costs. The results of this were striking: 29% on the road, 10% adjacent to the road, with numbers quickly reduced, arriving at 1% at 400 metres distant. These results will be used to direct and focus future management efforts.
..Top
|
