Road mortality in Swedish mammals: results of a drivers' questionnaire

Abstract

We present new estimates on the national road kill for nine large and medium‐sized mammals in Sweden. Our estimates are based on 705 drivers' reports on the number of animals accidentally hit during individually chosen reference periods. During 1960–2000, a total of 881 animal‐vehicle collisions were reported based on 243.6 million driven kilometres, representing 0.37% of the overall mileage driven in Sweden during 1992, the mean reference year of all replies. The collision frequencies ranged from 0.07 incidents per million kilometres for medium‐sized mustelids, over 0.42 for badgers Meles meles to 1.11 for hares Lepus spp. Our data suggest that during 1992, 7,000–13,500 moose Alces alces, 43,500–59,000 roe deer Capreolus capreolus, 63,500–81,500 hares, 22,000–33,000 badgers and 6,500–12,500 red foxes Vulpes vulpes may have been killed on Swedish roads. Among these game species, the extrapolated nation‐wide road kill ranged between 7 and 97% of the average annual harvest, and between 1 and 12% of the assessed total populations in 1992. Our results are in agreement with other independent road kill estimates for Sweden. The data suggested an overall increase in the frequency of road kills over the past 40 years, which partly can be attributed to changes in traffic volume and wildlife population sizes (game bags). In most species, the estimated levels of nation‐wide road mortality are not alarmingly high, although local impacts may be significant. In badgers and hares, the ratio of the estimated road kill to the annual harvest increased two fold, suggesting a steady increase in the relative importance of road mortality. We conclude that interviews with drivers can provide a cheap and useful index of wildlife traffic mortality.

Traffic mortality of four ungulate species in southern Finland

“…We found the collision and traffic mortality rate of moose to be 6.5% and 4.5% of the population, respectively. This was similar to what Seiler et al (2004) estimated in Sweden, but lower collision rates have been found elsewhere (Groot Bruinderink andHazebroek 1996, Joyce andMahoney 2001). The roe deer traffic mortality rate found by us was in concurrence with what other European countries reported in the early 1990s, while the fallow deer mortality rate was somewhat higher than reported elsewhere (Groot Bruinderink and Hazebroek 1996).…”

“…Joyce and Mahoney (2001) calculated the same ratio for moose (Alces alces) in Newfoundland, Canada, and found that the traffic mortality was only approximately 3% of the annual allowable harvest quota or 0.6% of the total population. In Sweden, these numbers were 10.1% and 4.0%, respectively (Seiler et al 2004).…”

“…The actual amount of collisions, and hence the amount of road-killed animals, is affected by several factors. Population size is one of the important variables explaining the number of UVCs (Lavsund et al 2003, Seiler 2004, Rolandsen et al 2011). In addition, though not always simple and linear, traffic volume is probably one of the key factors affecting the number of UVCs (e.g.…”

“…Ungulate-vehicle collisions (UVCs) are a notable and increasing traffic safety problem in Europe, North America, and Japan, and are therefore intensively studied in many countries (Groot Bruinderink and Hazebroek 1996, Romin and Bissonette 1998, Seiler 2004, Huijser et al 2009, Morelle et al 2013. Nevertheless, human injuries and fatalities (e.g.…”

“…For example, the traffic mortality of roe deer (Capreolus capreolus) has varied between 13% and 16%, depending on the country (Groot Bruinderink and Hazebroek 1996, Seiler et al 2004, Pokorny 2006. Joyce and Mahoney (2001) calculated the same ratio for moose (Alces alces) in Newfoundland, Canada, and found that the traffic mortality was only approximately 3% of the annual allowable harvest quota or 0.6% of the total population.…”