how long do the dead survive on the road carcass persistence probability and implications for road-kill monitoring surveys死者生存多长时间在路上尸体持久性概率和影响被车压死的监测调查.pdfVIP

How Long Do the Dead Survive on the Road? Carcass Persistence Probability and Implications for Road-Kill Monitoring Surveys 1,2 ¤ 1,2¤ ´ 1,2¤ Sara M. Santos * , Filipe Carvalho , Antonio Mira ´ ´ 1 Conservation Biology Unit, Department of Biology, University of Evora, Evora, Portugal, 2 Mediterranean Ecosystems and Landscapes Unit, Institute of Mediterranean ´ ´ Agrarian and Environmental Sciences, University of Evora, Evora, Portugal Abstract Background: Road mortality is probably the best-known and visible impact of roads upon wildlife. Although several factors influence road-kill counts, carcass persistence time is considered the most important determinant underlying underestimates of road mortality. The present study aims to describe and model carcass persistence variability on the road for different taxonomic groups under different environmental conditions throughout the year; and also to assess the effect of sampling frequency on the relative variation in road-kill estimates registered within a survey. Methodology/Principal Findings: Daily surveys of road-killed vertebrates were conducted over one year along four road sections with different traffic volumes. Survival analysis was then used to i) describe carcass persistence timings for overall and for specific animal groups; ii) assess optimal sampling designs according to research objectives; and iii) model the influence of road, animal and weather factors on carcass persistence probabilities. Most animal carcasses persisted on the road for the first day only, with some groups disappearing at very high rates. The advi