Browsing by Subject "Ungulates"

The expanding road network and increasing traffic volumes impose a barrier between different wildlife habitats and populations. Wildlife-vehicle collisions are a factor that affects wildlife, human safety, and property. Road Wildlife crossing structures, such as overpasses and underpasses, are built to enable landscape connectivity, improve traffic safety, and mitigate the impact roads have on wildlife. Crossings structures include structures that are built only for wildlife use or for the use of both wildlife and humans. The latter are called multiuse overpasses. Building large structures, like crossing structures, is expensive, therefore it is more cost-effective to build crossing structures suitable for both wildlife and humans. Human disturbance can influence the effectivity of crossing structures. Information about how human disturbance affects wildlife is needed to study the effectiveness of multiuse overpasses. In this thesis I evaluated the effects human disturbance have on ungulate multiuse overpass use. Using camera trap data from 9 multiuse overpasses located in southern Finland, I studied the effect of different human disturbances (non-motorized, motorized) on different ungulate species, and possible spatiotemporal avoidance. The overpasses were located on highway 1 between Helsinki and Turku, on highway 7 between Loviisa and Vironlahti, and on highway 4 in Heinola. All overpasses had a landscaped side with vegetation and a gravel or dirt road. The camera traps were located in the middle of the overpass, approximately one meter above ground level. I considered one camera trap picture to be one individual crossing event, regardless of the number of animals in the picture. During the monitoring period from December 2019 to May 2020, and November 2020, I detected 730 ungulate crossings, made by moose (Alces alces), white-tailed deer (Odocoileus virginianus), and roe deer (Capreolus capreolus). There were 4 707 crossings made by humans hiking, dog walking, cycling, driving a car, a motorbike, a snowmobile, a tractor, or a truck. While ungulates used the overpasses most active during the early evening, human activity peaked during the day. The results show that the time between non-motorized disturbance and an ungulate crossing was longer than the time between motorized disturbance and an ungulate crossing. The presence of spatiotemporal avoidance was evaluated by comparing time differences between crossing type pairs. I studied the possible spatiotemporal avoidance by calculating time differences between an ungulate crossing after an ungulate, and an ungulate crossing after a human. The reaction to human disturbance differed between the species, with only moose showing signs of spatiotemporal avoidance when comparing times between a moose crossing after a moose and a moose crossing after a human. Roe deer and white-tailed deer did not show signs of spatiotemporal avoidance. An explanation for the results regarding spatiotemporal avoidance, can be linked to the differences in ungulates natural habitats when comparing moose, roe deer and white-tailed deer. Moose ́s preferred habitat is large, forested areas, whereas roe deer and white-tailed deer occupy farmland, suburban areas, and areas in proximity to humans. The natural habitat of moose in itself results in minimal contact with humans. The results of this thesis show that multiuse overpasses are to some extent successful, in working as a crossing structure for both ungulates and humans. The results regarding avoidance from moose, indicate that the effects of human-caused disturbance need to be considered with severity. Therefore, we cannot cling to the thought that multiuse overpasses would be sufficient for all species in every situation, but we need to be prepared to provide crossing structures for only wildlife use or limit the human use of crossing structures if needed.