recognition, evaluation, mitigation · 2010-02-27 · • over- and underpasses for wildlife,...

Identifying and locating potential road / wildlife conflictsAvailable indicators:· police records on traffic casualties with moose and deer· field inventories on traffic killed mammals and birds· known conflict areas for other animals (mostly amphibiens)· crossings between ecological- and built-up infrastructure

(e.g. green corridors, creeks, ridges and small roads)· known migration routes, population densities and dynamics,

distribution of essential-preferred habitats

1. Locating barrier conflicts

Andreas Seiler (andreas.seiler@nvb.slu.se), Grimsö Wildlife Research Station, Department ofConservation Biology, Swedish University of Agricultural Sciences (http://www-grimso.slu.se)

Road & wildlife conflicts inRecognition, Evaluation, Mitigation

Sweden

Finding technical solutions for mitigation· over- and underpasses for wildlife, ecoducts· combined passages for traffic and fauna· fencing (as barrier and as directing structure in

combination with passages)· compensation measures (habitat replacements)· avoidance of critical areas to prevent mitigation needs

3. Mitigation

Fragmentation effects of infrastructure:

Indirect effects� access to land

(tourism, hunting)� altered land use� human settlement� secondary development

Direct effectsa) habitat lossb) disturbanced) corridorc) barriere) mortality

ECOLOGICAL EFFECTS� Environmental Impact Assessment methods insufficient in

predicting ecological effects on wildlife and landscapes.� Collisions with wildlife cause increasing material damage,

human injuries, train delays, insurance costs and irritation(comprizing 60% of all accidents).

� About 3000 km of wildlife fences on public roads increasetraffic safety but isolate deer populations and disrupt migra-tory routes.

� Improved mitigation is demanded by public, environmentalpolicy and for traffic safety.

THE PROBLEM:

Putting the road in a tunnel may becheaper than building overpasses

Checking otter tracks on an artificialpathway under a bridge in Norrtälje

Simple frog-tunnel in Fjugesta hasproven effective

Field inventories revealed: Existing usual road underpassesare too small to promote the use by deer, moose and hare.Drainage culverts are frequently used by badgers and foxes.

Photo: H-H Krüger

(c): IENE

Extra long bridge providing goodpassage for wildlife

Underpass for tertiary road aspotential wildlife passage?

For whom, where and when?Effects differ between species, landscapes and road types!

Target Species:· large game species (moose, deer), large carnivores (bear,

wolf, lynx), mustelids (badger, otter), amphibians, fish

Sensitive areas:· undisturbed and continous wilderness areas· small-scaled, cultural mosaic landscapes· riparian and coastal habitats· designated areas and networks for nature protection Evaluation criteria: (recommended)· assumed effect on target or indicator species· traffic safety and environmental issues (locally and regional)· strategic relation to the network of sensitive or designated

areas (ecological corridors)· possibility of improving existing measures to meet wildlife

needs

2. Setting priorities for mitigation

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(c): Swedish National Road Administration Photo: Eric Öman Photo: A. Seiler Photo: Natur & Skog Photo: Maya Rudin

Example: Wildlife mitigation plan for new highway E4in southern Sweden (Thyréns Infrakonsult)

Methods:- identifying target species: fenced motorway =large game- mapping habitat distribution: satellite and topographic data- identifying potential corridors: vegetation, water, topography- analyzing traffic casualties: spatial distribution- gathering experiences from local hunters on wildlife movements- evaluating possibilities to combine game and traffic passages

Accepted solution:- adaptation of 9 road underpasses and 6 water culverts to large wildlife

along the 26 km motorway (widening, altered design)

Conclusion:- additional costs for adaptation ca. 2 Mio.US$

(2% of total costs for motorway construction)

- field inventories on road killed wildlife- GIS-analysis of road kills in

relation to infrastructure,landscape composition, andanimal population

- monitoring studies of the effectsof (new) roads on wildlife

- monitoring of (new) roadpasssages for use by wildlife

Research activities

Localizing conflict pointsHow many passages are needed?

(c): Swedish National Road Administration

Crossings between road andecological corridors

Photo: A. Seiler

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Information IENE Infra Eco Network Europe(http://iene.vv.se)

Swedish National Road Administration(http://www.vv.se)

COST-action 341: Habitat fragmentation due toinfrastructure (see IENE homepage)