Browsing by Author "Huijser, M.P."

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Animal Vehicle Collision Reduction and Habitat Connectivity Pooled Fund Study – Literature Review
(Nevada Department of Transportation, 2021-12) Huijser, M.P.; Ament, Robert J.; Bell, M.; Clevenger, A. P.; Fairbank, E.R.; Gunson, K.E.; McGuire, T.
This report contains a summary of past research and new knowledge about the effectiveness of mitigation measures aimed at reducing animal-vehicle collisions and at providing safe crossing opportunities for wildlife. The measures are aimed at terrestrial large bodied wild mammal species, free roaming large livestock species (e.g. cattle, horses), free roaming large feral species (e.g. “wild” horses and burros), and small animal species (amphibians, reptiles, and small mammals). While mitigation is common, it is best to follow a three-step approach: avoidance, mitigation, and compensation or “off-site” mitigation. If reducing collisions with large wild mammals is the only objective, the most effective measures include roadside animal detection systems, wildlife culling, wildlife relocation, anti-fertility treatments, wildlife barriers (fences),and wildlife fences in combination with wildlife crossing structures. If the objectives also include maintaining or improving connectivity for large wild mammals, then wildlife barriers (fences) in combination with wildlife crossing structures are most effective. Measures for large domestic mammal species are largely similar, though for free roaming livestock there are legal, moral and ethical issues. For small animal species, temporary or permanent road closure and road removal are sometimes implemented, but barriers in combination with crossing structures are the most common.
Best Practices Manual to Reduce Animal-Vehicle Collisions and Provide Habitat Connectivity for Wildlife
(Nevada Department of Transportation, 2022-09) Huijser, M.P.; Fairbank, E.R.; Paul, K.S.
The goal for this manual is to provide practical information for the implementation of mitigation measures that aim to: 1. Improve human safety through reducing collisions with large animals, including large wild mammal species, select free roaming large feral species, and select free roaming large livestock species, and 2. Improve or maintain habitat connectivity for terrestrial wildlife species and selected feral species through safe crossing opportunities. This manual does not include all possible measures that can or may reduce animal-vehicle collisions and maintain or improve habitat connectivity for wildlife. The measures included in this manual are: Barriers (fences) in combination with crossing structures (for large wild mammals and for small wild animal species), roadside animal detection system, Barriers (fences), Barriers (fences) in combination with crossing structures (for free roaming livestock), and culling, relocation, anti-fertility treatment, roadside animal detection systems, barriers (fences), and barriers (fences) in combination with crossing structures (for large feral mammal species such as feral horses and burros).
The effectiveness of electrified barriers to keep large mammals out of fenced road corridors
(Nevada Department of Transportation, 2022-09) Huijser, M.P.; Getty, S.C.
For this project the researchers investigated the effectiveness of different types of electrified barriers for varying traffic volume and traffic speed. Some barriers were investigated for carnivores only, whereas others were evaluated for both ungulates and carnivores. Finally, we combined the data from our field studies with those reported in the literature and conducted a meta-analysis to investigate the effectiveness of different types and dimensions of barriers for both ungulates and carnivores. In general, electrified barriers can be a substantial barrier to species with paws, including black bears. However, careful maintenance and monitoring is required for these measures to succeed.
Electrified Barriers Installed on Top of Wildlife Guards to Help Keep Large Wild Mammals Out of a Fenced Road Corridor
(Western Transportation Institute, Montana State University, 2023-12) Huijser, M.P.; Getty, S.C.
Most wildlife mitigation measures along highways are aimed at improving human safety, reducing direct wildlife mortality, and providing safe crossing opportunities for wildlife. Fences in combination with wildlife crossing structures are the most effective combination of mitigation measures to achieve these objectives. For fences to reliably reduce collisions with large wild mammals by 80% or more, at least 5 kilometers (3 miles) of road length needs to be fenced, including a buffer zone that extends well beyond the known hotspots for wildlife-vehicle collisions. Collisions that still occur within the fenced road sections tend to be concentrated near the fence-ends. In addition, gaps in fences, including at access roads, can result in concentrations of collisions inside fenced road sections. Gates are commonly used at gaps in the fence at low traffic volume access roads, but they are often left open allowing wildlife to access the road corridor. While cattle guards or wildlife guards can be effective for some ungulate species, double wide cattle or wildlife guards consisting of round bars or bridge grate material, situated above a pit, are generally recommended for ungulates. However, such guards are not a substantial barrier for species with paws, including many carnivore species. Electrified mats or electrified guards can be a barrier for both ungulates and species with paws, but to prevent animals from jumping across the mat, they need to be 4.6-6.6 m (15-22 ft)) wide. For this project, a combination of wildlife guards and electrified barriers on top of these wildlife guards was evaluated. Both electrified mats that were tested (Crosstek and BS Fabrications) on top of existing wildlife guards resulted in a near absolute barrier for both ungulates and species with paws (97.9% barrier for the 2 deer species combined, 100% barrier for coyotes and black bears); an improvement to a wildlife guard only without an electrified mat (89.3% for the 2 deer species combined, 54.5% barrier for coyotes and 45.5% barrier for black bears). Based on the images, there is evidence that a shock is delivered to the animals that touch the electrified mats and that most of the animals respond by returning to the habitat side of the barrier. Specifically for bears, if it was not for the electrified barriers, likely at least 3 black bears and 1 grizzly bear would have crossed into the fenced road corridor where they would have been exposed to vehicles.
Final Report 2022: Update and expansion of the WVC mitigation measures and their cost-benefit model
(Nevada Department of Transportation, Carson City, NV, 2022-10) Huijser, M.P.; Duffield, J.W.; Neher, C.; Clevenger, A.P.; McGuire, T.
This report contains an update and an expansion of a cost-benefit model for wildlife-vehicle collisions and associated mitigation measures along highways, that was originally calculated in 2007 US$ and published in 2009. The direct cost values (vehicle repair, human injuries, human fatalities) were updated for deer, elk, and moose, and expanded by including additional species: gray wolf (Canis lupus), grizzly bear (Ursus arctos), and free ranging or feral domesticated species including cattle, horse, and burro. The costs associated with collisions were also expanded by including passive use, or nonuse values associated with the conservation value of selected wild animal species. The total costs (in 2020 US$) associated with a collision with deer, elk and moose were about 2-3 times (direct costs only) or about 3-4 times higher (direct costs and passive use values combined) compared to the values in 2007 US$. The passive use costs associated with threatened species (wolf, grizzly bear) were higher or much higher than the direct costs. The costs associated with mitigation measures (especially fences and wildlife crossing structures) were also updated and supplemented with new data. New cost-benefit analyses generated updated or entirely new threshold values for deer, elk, moose, and grizzly bear. If collisions with these large wild mammal species reach or surpass the threshold values, it is economically defensible to install the associated type and combination of mitigation measures, both based on direct use and passive use parameters and their associated values. The trend in increasing costs associated with vehicle repair costs, costs associated with human injuries and fatalities, and through including passive use values for wildlife is that we learn that the implementation of effective mitigation measures can be considered earlier and more readily than based on the cost-benefit model published in 2009.