ARPHA Preprints, doi: 10.3897/arphapreprints.e103281
Mammal use of underpasses to cross Route 606 in Guacimal, Costa Rica  
expand article infoEleanor R. Terner
‡ University of California, San Diego, United States of America
Open Access

Roads severely affect the health of ecosystems across the globe by fragmenting habitats, reducing population connectivity, and increasing animal mortality. Wildlife underpasses allow for increased road permeability–the ability for animals to safely cross the road. Despite growing success in other regions, underpass usage in Central America is critically under-researched. In this study, I monitored two dry circular culverts and two unfenced tunnels on Route 606 in Guacimal, Costa Rica, from 22 November to 6 December 2021 using 14 camera traps to assess which species used them to cross. Twelve species used the culverts and tunnels for a total of 108 individual crossings. The tunnels were used, in descending order, by agouti (Dasyprocta punctata), opossum (Didelphis marsupialis), dog (Canis familiaris), armadillo (Dasyous novemcinctus), cat (Felis catus), Norway rat (Dasypus novemcinctus), ocelot (Leopardus pardalis), squirrel (Sciurus variegatoides), tamandua (Tamandua mexicana), and coati (Nasua narica). The circular tunnel, Tunnel 1, was used more frequently and by a greater diversity of species than observed in the square tunnel, Tunnel 2. The two smaller culverts were used by opossum (Didelphis marsupialis), cat (Felis catus), rat opossum (Micoureus alstoni), and Watson’s climbing rat (Tylomus watsoni). Culvert 2 was used more frequently; however, Culvert 1 was used by a greater diversity of species. Species such as coyote (Canis latrans) and gray fox (Urocyon cinereoargenteus) were captured in the surrounding fragments but not using any underpass. This study highlights wildlife underpasses as a critical strategy for biological conservation in Costa Rica though improved road safety and habitat connectivity.


Camera Trapping, Central America, Habitat Fragmentation, Road Ecology, Wildlife Crossing Structures.