10.5061/DRYAD.S4MW6M96Q
Mayer, Martin
0000-0002-9905-3625
Aarhus University
Coleman Nielsen, Jacob
Aarhus University
Elmeros, Morten
Aarhus University
Sunde, Peter
Aarhus University
Deer-vehicle collisions in Denmark
Dryad
dataset
2021
FOS: Biological sciences
2021-06-29T00:00:00Z
2021-06-29T00:00:00Z
en
3691142 bytes
2
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Vehicles collide with hundreds of thousands of deer on European roads each
year. This leads to animal deaths and suffering, economic damage and risks
for human safety, making the reduction of road mortality a major field in
conservation biology. In order to successfully reduce roadkill, we need
improved knowledge regarding spatio-temporal patterns of deer-vehicle
collisions (DVCs) on a landscape scale. Here, we analyzed >85,000
DVCs collected over 17 years in Denmark to investigate changes in the
number of DVCs over time and to find spatio-temporal patterns of DVC
occurrence. We used a use-availability design – originally developed for
habitat selection analyses – to compare DVCs involving roe deer (Capreolus
capreolus), red deer (Cervus elaphus) and fallow deer (Dama dama) with
random road locations on a landscape scale. This approach enabled us to
combine temporal (seasonal and diel variation), spatial (land cover, road
density and type) and other relevant variables (deer population density,
traffic, and deer activity) within the same analysis. We found that
factors related to infrastructure and land cover were most important in
explaining patterns of DVCs, but seasonal and diel changes, deer activity,
and population density were also important in predicting the occurrence of
DVCs. Importantly, patterns of DVCs were largely similar between the three
deer species, with more DVCs occurring at intermediate traffic density,
increasing forest cover, during dusk and dawn, and with increasing deer
activity and population density. The strong and consistent patterns found
here will allow the development of flexible mitigation measures. We
propose that our findings could be used to develop a spatio-temporally
flexible warning system for smartphones and navigation systems that is
based on existing map providers, making it a widely available and cheap
mitigation measure.
Data on deer-vehicle collisions for roe deer (Capreolus capreolus), red
deer (Cervus elaphus), and fallow deer (Dama dama) were collected
countrywide in Denmark (Fig. 1). A corps of hunters, supervised under the
“Schweiss-register” by the Danish Nature Agency, conducted tracking and
euthanasia of traffic-injured deer with specially trained tracking dogs.
From 2003-2010, it was mandatory for tracking dog handlers to register the
exact location of DVCs, date and time for all DVCs they were called for,
as well as information on species, sex and age class if available. From
2011-2016, only the number of annual DVCs was registered without
information on spatial location (not shown in this data set), but from
2017-2019 the spatial location was again registered although not the time
of day.
Coordinates (Lat/Lon) are given in WGS 1984. Fawns/calves were defined as
individuals in their first year of life (May 1 was used as cut-off date),
yearlings as individuals in their second year of life, and adults all
individuals >2 years. Roads were categorized into (1) ≥3-6 m wide
(speed limit 50-80 km/h), (2) >6 m wide (speed limit 50-80 km/h),
(3) expressways (speed limit 80-110 km/h, with restrictions on traffic
types and grade crossings), and (4) motorways (speed limit 80-130 km/h,
multilane road with controlled access and no grade crossings). Land cover
types were categorized into arable fields, built up areas (including any
property in the country with a building on it, i.e., including gardens,
farmsteads etc.), heathland, fallow (areas taken out of agricultural
production), forest, water bodies, and pastures.