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February 2010
Why did the turtle cross the road? Yes, in fact, it did want to get the other side. And so do a host of mammals, amphibians, fish, birds and reptiles. Our necessary network of roads has diced up habitats, disconnecting nest and forage sites from water and bisecting migration paths. The Oregon Conservation Strategy identifies “Barriers to Fish and Wildlife Passage” as one of the key conservation issues in the state, and many people and organizations are working to provide room for the natural movement of animals across the landscape.
CONTENTS
Connecting the Dots for Wildlife
Missouri Bottoms Bridge Crosses Cars and Critters
Statewide Projects Illustrate Range of Solutions
Bats and Bridges
Turtles and Roads
Wildlife Movement Strategy Working Group
One Small Thing
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| Metro photo. |
CONNECTING THE DOTS FOR WILDLIFE
If you think navigating Portland metropolitan streets is getting harder, consider the challenges facing a deer, an owl or a salamander. While roads and railroads are necessary for people and commerce, they can create dangerous barriers for wildlife.
“One of reasons people like living in Portland is the abundance of natural areas,” said Lori Hennings, Senior Natural Resource Scientist for Metro. “And those parks, rivers and forests are home to a lot of wildlife.”
How those wildlife get around—and they need to as they move between habitats seeking food, prey, mates, nesting habitat and following age-old migration paths—is of concern to regional planners and those who value wildlife. Frogs, newts, turtles and owls are increasingly becoming road kill, and deer and elk vehicle collisions kill large numbers of animals and threaten human safety.
Hennings believes providing safe passage for wildlife is possible despite the fact that within 25 years the area is expected to grow by a million people.
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| The Port of Portland created a culvert underpass to help Oregon’s native turtles stay out of the road. ODFW photo. |
“We are mapping wildlife corridors and considering how to connect wildlife habitat,” said Hennings. “We are trying to answer questions like: How large a gap in tree cover will an animal feel safe crossing? Can we expect wildlife species to share one corridor or do we need two? How can trails be best placed to minimize wildlife disturbance?”
Metro staff have already done a lot of work on wildlife crossings. In 2009, they published Wildlife Crossings: Providing Safe Passage for Wildlife. Designed for transportation and city planners, the book provides recommendations on how to build or enhance wildlife crossings such as underpasses, walkways through culverts and overpasses. Information on fencing, lighting and plantings for specific wildlife species is also included.
Hennings and others at Metro are currently completing a literature review of about 400 studies concerning urban wildlife connectivity to glean information for mapping key wildlife habitat and connecting corridors.
“It’s an exciting time to be involved in this work,” said Hennings. “There is a lot to learn, but more and more people are becoming aware of the problem—they realize we have taken big pieces out the puzzle of wildlife habitats, and that we have to bridge them in some way.”
For a copy of the wildlife crossings guidebook or more information, contact Lori at lori.hennings@oregonmetro.gov
Metro is Portland’s elected regional government serving more than 1.5 million residents in Clackamas, Multnomah and Washington counties and the 25 cities in the Portland region.
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| Missouri Bottoms Bridge, in Myrtle Creek south of Roseburg, allows animals to naturally follow riparian areas under the highway. ODFW photo. |
MISSOURI BOTTOMS BRIDGE CROSSES CARS AND CRITTERS
Thanks to the new Missouri Bottoms Bridge in Douglas County, blacktail deer, bobcats, raccoons, amphibians and turtles can now safely traverse Myrtle Creek without crossing heavily traveled I-5. Bridge construction was completed in the fall of 2009, and already deer have established heavily-used trails under the bridge.
“With the new design, animals can naturally follow riparian areas under the highway,” said Jim Muck, ODFW transportation liaison. “It gives them safe passage to reach water, food and cover and provides a corridor for migrations to winter or summer range.”
These crossing improvements are the result of a collaboration between the Oregon Department of Transportation and ODFW and falls under an agreement between state agencies to incorporate improved fish and wildlife standards when replacing bridges.
“The agreement covers 365 bridges, 125 of which are replacement bridges over water,” said Geoff Crook, ODOT's environmental program manager. “As projects are designed and contractors hired, we make sure that fish and wildlife habit connections are maintained or reestablished. We allow for wildlife terraces and leave room for the river channel to rise and fall naturally.”
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| Missouri Bottoms Bridge leaves room for deer, bobcats, amphibians and turtles to safely bypass I-5. ODFW photo. |
Construction is also managed to higher standards as water pollution is contained and equipment and slurry managed. During construction of the Missouri Bottoms Bridge, fish were captured and released at nearby sites to avoid loss during certain phases of the project.
The ODOT programmatic permitting agreement includes ODFW, Department of State Lands, U.S. Army Corps of Engineers and the National Marine Fisheries Services and provides for environmental performance standards that enhance fish and wildlife habitat during bridge construction. The agreement was signed in 2004 and incorporates monitoring of a number of the bridges over the long-term to evaluate how the wildlife strategies are working.
For a copy of the Bridge Program Performance Standards for ODOT Bridge Repair and Replacement Regional General Permit (pdf) document, visit ODOT’s website.
STATEWIDE PROJECTS ILLUSTRATE RANGE OF SOLUTIONS
There are a number of tools available for those who want to provide fish and wildlife movement across roads including signs; animal detection systems; road and bridge design; fencing; fish screens; culverts; under and over passes; and public education. What tools are used depends on a number of things including the severity of the problem, needs of the species involved, policy guidelines, public support and budgets. Here are a few examples of how problems are being addressed around the state.
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The Oregon wildlife movement work group met in Lincoln City to tour an area where a resident elk herd regularly crosses Hwy. 101 to forage.
Photo courtesy of ODFW |
Fencing and road design: Boeckman Road in Wilsonville showcases a number of wildlife crossing strategies. During design of the new road, which transects a wetland, the City and ODOT planners incorporated culverts, exclusion fencing and an amphibian wall to allow wildlife safe passage. The fencing and the wall keep wildlife from entering the highway and funnel them to culverts and an underpass so they can safely cross. For more information.
- Signage: After losing two bighorn sheep to vehicle collisions, wildlife crossing signs will be posted on a county road in Burnt River Canyon. “The sheep just hang out in the road out there,” said Nick Myatt, ODFW wildlife biologist in Baker City. “The grass along the road greens up early and in summer, the sheep have to cross the road to get to water.”
- Public Outreach: A citizen advisory group is meeting to help with public outreach and education concerning the resident elk herd that regularly crosses Hwy. 101 near Lincoln City. The highway is curvy and its many access points make it difficult to manage wildlife crossings, but a group of interested people are committed to finding a solution.
- Bridge design: A wildlife pathway or “bench” was incorporated into a bridge replacement on the Zigzag River, a tributary of the Sandy, to allow for mammal passage. The bench is a flat, vegetated area under the bridge, just above the high water line, that facilitates animal movement. A recent site visit showed many animal tracks.
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| A bridge over the Zigzag River incorporates a wildlife bench that gets heavy use by a variety of animals. |
Road underpass: Two wildlife underpasses and fencing have been incorporated into an expansion of Highway 97 south of Bend—one is exclusively for wildlife, the other shares a road designed for vehicle traffic. About a hundred mule deer die on a four-mile section of the road every year, usually during annual migrations when the animals move to and from the west slope of the Cascade Mountains to habitat east of Highway 97. More information.
- Fish screens and culverts: Road culverts can inhibit passage of native fish. Fish screens which prevent fish from being drawn into a water diversion mechanism can reduce fish mortality and good culvert design assists fish passage. A culvert replacement on Coal Creek improved spawning and rearing habitat for salmonids by increasing culvert size and placing boulders within it to create eddies and pools. Partners are Benton County Public Works, OWEB and ODFW. More information on the ODFW Fish Passage Program.
Visit ODFW Wildlife Connectivity on the website to learn more.
BATS AND BRIDGES
With the decline of much of their natural habitat, bats are increasingly turning to bridges to roost. As a result, ODFW and ODOT work to include bat habitat into new bridges and protect existing habitat during bridge repairs.
”The preferred approach is to engineer habitat into bridge design,” said Simon Wray, ODFW/ODOT coordinator. “We have been successful in developing designs that can be used for different bridge types and don’t impact structural integrity or construction costs.”
Bridge repair is another subject, however. The John Day River Bridge on Highway 19, which will undergo repairs in 2012, is home to a large maternal colony of Townsend’s big-eared bats from late spring through early fall. The colony’s roost site is in the bridge’s hollow box beams which will be closed during renovation. Alternate roosting habitat is being prepared now before the bats return in April or May.
“We will install several large hollow boxes under the deck at the both ends of the bridge to provide a new roost site for the bats,” said Wray. “Having the boxes in place a full year before the box beams are sealed off gives the bats a chance to get used to the new boxes and increases the likelihood that they will be fully accepted when the bats no longer have access to their old roost.”
Townsend’s big-eared bats are listed as a sensitive species in the state. For information about Oregon’s bats, see Conservation Summaries for Strategy Species in Section B of the Strategy.
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| Watch for turtles on land from late winter through the summer as they move between winter habitats or look for nest sites. ODFW photo. |
TURTLES AND ROADS
In late winter and early spring, turtles wake from hibernation and start to move around on the landscape, looking for food and mates. Despite their sedentary reputation, some turtles travel more than a half mile between habitats.
“Western painted and western pond turtles start to emerge from winter habitats at this time of year,” said Susan Barnes, ODFW Regional Conservation biologist. “Those that have wintered in upland woody areas and forests move back to ponds, and those that winter in the bottom of muddy ponds and sloughs surface. As the days get warmer you will be able to see them basking on logs.”
In May and June, females begin searching for suitable nesting grounds to lay their eggs. “If you see a turtle on the ground, the best thing to do is leave it alone and let it continue on its path,” said Barnes.
She also warns motorists driving along streams and rivers to watch for turtles crossing roadways; sometimes the only way a turtle can reach water or suitable habitat, is to cross a road.
“Stopping to help a turtle cross a road is always a question of human safety,” said Barnes. “If you can safely get off the road and carry the turtle to the side of the road in the direction it is headed, it’s O.K.”
The western pond turtle, one of Oregon’s two native turtle species, lives in western Oregon. Females may travel as far as a half mile from water, although most nest within 100 yards of a water source. The painted turtle ranges from the Columbia River Gorge eastward and nests in sandy or grassy areas near water.
If you see native turtles in the Willamette Valley, biologists are interested in knowing where they are and have created a website for reporting, https://www.oregonturtles.com/. It only takes a few minutes and is a good way for citizens to help conserve our dwindling native turtles.
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| Fish passage allows fish access to spawning, nursery and rearing habitat. ODFW photo. |
WILDLIFE MOVEMENT STRATEGY WORKING GROUP
The Wildlife Movement Strategy Working Group, co-chaired by ODFW and ODOT, is developing a statewide strategy to ensure fish and wildlife movement. One of the group’s accomplishments is the development of a wildlife linkage data set, Oregon Wildlife Linkage Areas. It is a GIS shapefile and comes with complex metadata, which should be reviewed before using the dataset. PDF maps and a final linkages report with the data are also available. A newer version of the dataset, which is simplified for ease of use will be available soon. For more information on the GIS data, contact Miranda Wood, (503) 947-6075, Miranda.L.Wood@odfw.oregon.gov
The interagency working group was formed in 2006 and is a step-down project from the Conservation Strategy. Partners include USDA Forest Service, Oregon Department of Forestry and the Bureau of Land Management. For more information, contact Mindy Trask, (503) 986-3504, Melinda.Trask@odot.state.or.us
ONE SMALL THING
Consider wildlife when you drive. Many large mammal collisions occur at dusk and dawn when light levels are low and animals are active. Be alert when you see a wildlife crossing sign and slow down. Learn about Oregon’s native species and what time of year they are likely to be moving on the landscape.
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ABOUT THE OREGON CONSERVATION STRATEGY
The Oregon Conservation Strategy provides a blueprint and action plan for the long-term conservation of Oregon’s native fish and wildlife and their habitats through a non-regulatory, statewide approach to conservation. It was developed by ODFW with the help of a diverse coalition of Oregonians including scientists, conservation groups, landowners, extension services, anglers, hunters, and representatives from agriculture, forestry and rangelands.
EDITOR
Meg Kenagy
Oregon Conservation Strategy Communications coordinator
(503) 947-6021
meg.b.kenagy@odfw.oregon.gov
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