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Providing evidence to improve practice

Individual study: Vertebrate use of culverts under roads and railways in Madrid province, Spain

Published source details

Yanes M., Velasco J.M. & Suarez F. (1995) Permeability of roads and railways to vertebrates: the importance of culverts. Biological Conservation, 71, 217-222


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Install tunnels/culverts/underpass under railways Terrestrial Mammal Conservation

A replicated study in 1994 of 17 culverts under roads and railways in Madrid province, Spain (Yanes et al. 1995) found that mammals used all 17 culverts studied. The highest frequencies of tracks was from wood mice Apodemus sylvaticus (2.5 tracks/culvert/day), shrews Sorex spp. (0.5/culvert/day) and European rabbit Oryctolagus cuniculus (0.3/culvert/day). Rats Rattus sp. (0.1 tracks/culvert/day), hedgehogs Erinaceus europaeus (0.01/culvert/day), cats (mostly wild cat Felis sylvestris - 0.04/culvert/day), red fox Vulpes vulpes (0.03/culvert/day), genet Genetta genetta (0.02/culvert/day) and weasel Mustela nivalis (0.01/culvert/day) were also detected. Small mammal use of culverts decreased with increased culvert length and increased with increasing culvert height, width and openness. Use by rabbits and carnivores decreased with increasing width of the railway or highway. Rabbit use also declined with increased boundary fence height. Vegetation complexity had little influence. Five culverts were monitored under railways, two under a motorway and 10 under local roads. Structural, vegetation and traffic variables were recorded at each culvert. Use was monitored using marble (rock) dust over culvert floors to record tracks. Sampling was undertaken in 1994, over four days each in spring, summer, autumn and winter. Sampling of four culverts extended to eight days when deer were in the vicinity.

(Summarised by Rebecca K. Smith)

Install tunnels/culverts/underpass under roads Terrestrial Mammal Conservation

A replicated study in 1994 of roads and railways in Madrid province, Spain (Yanes et al. 1995) found that all 17 culverts under roads were used by mammals. The highest frequencies of tracks were from wood mice Apodemus sylvaticus (2.5 tracks/day), shrews Sorex spp. (0.5/day) and European rabbits Oryctolagus cuniculus (0.3/day). Rats Rattus sp. (0.1 tracks/day), hedgehogs Erinaceus europaeus (0.01/day), cats (mostly wild cat Felis sylvestris - 0.04/day), red fox Vulpes vulpes (0.03/day), genet Genetta genetta (0.02/day) and weasel Mustela nivalis (0.01/day) were also detected. Small mammal use of culverts decreased with increased road width and culvert length and increased with increased culvert height, width and openness. Use by rabbits and carnivores decreased with increasing highway or railway width. Rabbit use also declined with increased boundary fence height (fences ran across culvert entrances, rather than funnelling animals towards them). Vegetation complexity had little influence. Five culverts were monitored under railways, two under a motorway and 10 under local roads. Structural, vegetation and traffic variables were recorded at each culvert. Use was monitored using marble (rock) dust over culvert floors to record tracks. Sampling was undertaken in 1994, over four days each in spring, summer, autumn and winter. Sampling extended to eight days at four culverts when deer were nearby.

(Summarised by Rebecca K. Smith)

Install culverts or tunnels as road crossings Amphibian Conservation

A replicated study in 1993 of 17 culverts in Madrid province, Spain (Yanes, Velasco & Suarez 1995) found that amphibians used the culverts. An average of 0.03 amphibian tracks/culvert/day (range: 0–0.19) were recorded. Two culverts were selected under a motorway, 10 under local roads and five under a railway line. Amphibian tracks were monitored within culverts using marble dust over the floor. Monitoring was undertaken over four to eight days each season.