The overwinter survival of female pygmy-possums was 96% of that at an undisturbed site after corridor construction, compared to 21% before. Over 28 days, mountain pygmy-possum were recorded in a monitored underpass 60 times, bush rats Rattus fuscipes 21 times and dusky antechinus Antechinus swainsonii three times. Supporting evidence from individual studiesĪ controlled, before-and-after, site comparison study in 1982–1986 of rock screes and boulder fields on a mountain in Victoria, Australia (Mansergh & Scotts 1989) found that an artificial rocky corridor, which included two underpasses, was used by mountain pygmy-possums Burramys parvus and female overwinter survival and male dispersal increased. Behaviour change (1 study): A controlled, before-and-after, site comparison study in Australia found that after an artificial rocky corridor, which included two underpasses, was installed, dispersal of mountain pygmy-possums increased.A study in the USA found that a range of mammals used culverts, including those with shelves fastened to the sides. A replicated study in Germany found that use of tunnels by fallow deer was affected by tunnel colour and design. A controlled, before-and-after, site comparison study in Australia found that an artificial rocky corridor, which included two underpasses, was used by mountain pygmy-possums. One of the studies found that crossing structures were used by two of four species more than expected compared to their movements through adjacent habitats. Use (23 studies): Seventeen of 20 studies (including seven replicated studies and two reviews), in the USA, Canada, Australia, Spain, the Netherlands, and across multiple continents, found that crossing structures beneath roads were used by mammals whilst two studies found mixed results depending on species and one study found that culverts were rarely used as crossings by mammals.A controlled, before-and-after, site comparison study in Australia found that overwinter survival of mountain pygmy-possums increased after an artificial rocky corridor, which included two underpasses, was installed. A review found that most studies recorded no evidence of predation of mammals using crossings under roads. Survival (3 studies): A study in South Korea found that road sections with higher underpass density did not have fewer wildlife-vehicle collisions.Eight studies were in the USA, four were in Australia, four were in Canada, two were in Spain, one each was in Germany, the Netherlands and South Korea and three were reviews with wide geographic coverage. Twenty-five studies evaluated the effects on mammals of installing tunnels, culverts or underpass under roads.There is an absence of studies reporting on wider population-level effects of the presence of these structures. Most studies here report solely on the use of these structures, such as the number of crossings made. Studies included here are those where barrier fencing is not installed or not explicitly referred to in the study methods or where at least some underpasses were in unfenced areas.
#Highway underpass install#
See also Install tunnels/culverts/underpass under railways. For this combined intervention, see Install barrier fencing and underpasses along roads. Underpasses are frequently installed in conjunction with wildlife barrier fencing which funnels animals towards the tunnel and prevents them from accessing the road. A range of different tunnels can be used, including purpose-built wildlife tunnels, culverts that assist with drainage and which can also be used by wildlife, and large passages beneath elevated road section which may sometimes also be used for local vehicle access. Tunnels, culverts and underpasses may provide safe road crossing opportunities for mammals.
0 kommentar(er)
