Strength of correlation between wildlife collision data and hunting bags varies among ungulate species and with management scale

Abstract

Most European ungulate species are increasing in numbers and expanding their range. For the management and monitoring of these species, 64% of European countries rely on indirect proxies of abundance (e.g., hunting bag statistics). With increasing ungulate numbers, data on ungulate-vehicle collisions (UVC) may provide an important and inexpensive, complementary data source. Currently, it is unclear how bag statistics compare with UVC. A direct comparison of these two indices is important because both are used in ungulate management. We evaluated the relationship between UVC and ungulate hunting bags across bioclimatic, regional, and local scales, using five time lags (t−3 to t+1) for the five most common wild ungulate species in Sweden. For all species, hunting bags and UVC correlated positively, but correlation strength and time lags varied across scales and among species. The two indices correlated most strongly at the local management scale. Correlation between both indices was strong for the smaller deer species and wild boar, in particular, but much weaker for moose where we found the best fit using a 2-year time lag. For the other species, indices from the same year correlated best. We argue that the reason for moose data behaving differently is that, in Sweden, moose are formally managed using a 3-year time plan, while the other species are not. Accordingly, moose hunting bags are influenced more strongly by density-independent processes than bags of the other species. Consequently, the mismatch between the two indices may generate conflicting conclusions for management depending on the method applied.

Large mammal telomere length variation across ecoregions

“…While moose and roe deer Capreolus capreolus occur throughout Sweden, the distribution of red deer Cervus elaphus , fallow deer Dama dama and wild boar Sus scrofa is limited to southern Sweden. Hunting pressure remained relatively stable for moose and roe deer in recent decades [ 57 ] but southern latitudes are experiencing higher hunting pressure due to the higher diversity of sympatric game species [ 26 , 27 ]. Prevalence of disease and parasites affecting moose health was also shown to be higher in southern Sweden moose populations compared to those in the north [ 24 , 25 ].…”

“…In addition, moose are a cold-adapted species and are susceptible to heat-stress at ambient temperatures above 14–17 °C [ 22 , 23 ] during summer and above − 5–0 °C during winter [ 22 ], meaning they may be particularly susceptible to temperature changes brought about by climate change. In combination with a known higher parasite burden [ 24 , 25 ], higher hunting pressure and higher inter-species competition [ 26 , 27 ] that moose are exposed to in their southern range, we expect the chronic stress burden of moose to decrease with increasing latitude. However, moose at high altitudes, i.e., montane tundra habitat, may experience stress due to other factors, such as high snow depth [ 28 ].…”

Evaluating the Management Success of an Alien Species Through Its Hunting Bags: The Case of the Sika Deer (Cervus Nippon) in the Czech Republic

“…The lack of information about ungulates related WVC represents a flaw in the management of these species. Thus, it would be important to systematically collect these data because, when the number of ungulates increases and the main source of data on their population is represented solely by the hunting bags, data on WVC may represent an important and inexpensive complementary data source (Neumann et al, 2020). Along with a pervasive road infrastructure, the Czech Republic also contains one of the densest railway infrastructures of Europe (Keken, Kušta et al, 2016;Keken and Kušta, 2017) that represents a further possible cause of wildlife mortality (S.C.V., 1996; Dorsey, Olsson et al, 2015;Santos, Carvalho et al, 2017), especially for the ungulates (Santos, Carvalho et al, 2017).…”

“…Whether hunting is a sufficient strategy for controlling populations of ungulates in the Northern hemisphere has been widely debated (Hagen, Haydn et al, 2018). Nevertheless, indirect proxies of abundance, such as hunting bags, are currently used as a reliable method by 64% of European countries (Neumann, Widemo et al, 2020). In the Czech Republic, hunt control records are known from the first half of the 9 th century and Czech game management statistics have been kept since 1966.…”

Moving towards an ecological management of overabundant ungulates: insights from wildlife-vehicle collisions and hunting bag data

“…We used traffic accident records and hunting bags of the three most abundant and widely distributed ungulates across Europe: the wild boar, the roe deer (Capreolus capreolus), and the red deer (Deinet et al 2013). Traffic accidents constitute a major impact of overabundant ungulates and can be also used as a proxy of population abundance in these species (e.g., Fernández-López et al 2022;Neumann et al 2020;Saint-Andrieux et al 2020). The study region, Castilla y León, is of particular interest to investigate this issue due to its socioecological context.…”