Central Washington University

CWU Wildlife Research Helps Guide I-90 Construction

CWU biology professor Kris Ernest and her small mammal team work near Snoqualmie Pass.

Central Washington University researchers are helping protect animals and motorists near Snoqualmie Pass as part of a major wildlife monitoring effort along Interstate 90. The project is the largest study of its kind ever conducted in the United States. The work is unique because the wildlife monitoring is occurring prior to construction.

“We’ve made some design changes on the project based on information from the CWU team,” said Brian White, the state Department of Transportation’s assistant regional administrator for project development and I-90.

White spoke during a meeting at CWU last week where biologists updated project partners on their latest efforts. Since 2008, WSDOT has funded research by CWU faculty and students at animal crossing zones on a 15-mile stretch of interstate. More than 20 large wildlife crossing structures—including three major overpasses—are proposed between Hyak and Easton as part of the ongoing I-90 Snoqualmie Pass East project. Wildlife fencing also will be installed.

CWU researchers are focused on fish, amphibians, and small mammals. They’re discovering what species inhabit the project area and are learning how the freeway affects animal behavior and survival.

Positive signs for bull trout

CWU biology professor Paul James, PhD, is studying fish populations and stream habitat in nine different creeks. Over the past three years his team has found the threatened bull trout in Coal Creek, Resort Creek, and Rocky Run Creek. James said bull trout are beginning to show signs of re-inhabiting streams other than Gold Creek for the first time in 50 years.

By electrofishing—using electricity to stun fish to catch them—James and his team also took tissue samples and tagged hundreds of cutthroat trout. They recorded a high recapture rate of 33 percent, which confirms their population estimates and reveals their methods aren’t harmful to the fish, James said.

The team’s research will help guide steam rebuilding efforts such as those planned on Noble Creek after crews remove a culvert. In the new channel, shade will be an important tool in maintaining cool water temperatures, James said. Proper streambed material and woody debris also are needed to create suitable fish habitat in the new stretch of creek, he added.

In 2013 crews removed a concrete slab from Rocky Run Creek and built a new channel. This year James and his team plan to monitor the new channel to see if fish have returned. Other projects planned this year include monitoring kokanee salmon spawning in Gold Creek, and installing tag antennas to monitor fish passage.

Tracking amphibians

Cascades frogs are the most abundant amphibians in the project area. The giant Pacific salamander is the second most plentiful.

“Amphibians are hard to find,” said CWU associate biology professor Steve Wagner, PhD. He used the term rock flipper to describe amphibian biologists.

Wagner and his team marked and tracked more than 1,500 amphibians on Snoqualmie Pass. They found several toads that were killed by vehicles on Forest Service Road 4832, while others died from the stress of breeding and of Chytrid fungus, a disease responsible for the decline and extinction of some amphibians worldwide. The team even radio-tracked a frog that had been eaten by a snake.

They learned that Cascade frogs are able to cross I-90. They did not observe any toads or salamanders crossing I-90, but they do cross Forest Service roads.

Moving forward, the team plans to link amphibian occupancy rates to landscape features and microhabitat to help inform crossing structure design. They also will investigate the effectiveness of cover objects in crossing structures and woody debris.

Wagner said in the future he would like to do environmental DNA (eDNA) research, which involves collecting DNA left behind by animals. Simply explained, biologists could extract DNA from a water sample and the traces left behind could reveal, in a non-invasive manner, which species live in streams and ponds. It will also help to understand the long-term ecological connectivity of species in the Cascades.

Small mammal connectivity

CWU biology professor Kris Ernest, PhD, and her team have been studying low-mobility wildlife in the Price Creek and other areas near I-90. The research will help guide habitat building on top of and under two 120-foot overcrossings with small mammals in mind

The team used several types of live traps to capture Keen’s mice, Pacific jumping mice, red-backed voles, shrews and other animals. They swabbed cheeks to collect genetic samples and used a dab of pink fingernail polish to mark which animals had already been captured. The team caught 129 individual animals representing nine species—all of which were native.

Working nearby, WSDOT biologists captured a non-native Norway rat. It is suspected the rat hitched a ride to the Price Creek rest stop. They also recorded one instance where a Keen’s mouse marked by Ernest’s team crossed I-90.

The pika, a small mammal with round ears that makes a high-pitch squeak, is a major focus of Ernest’s research. Her team is working to determine how connected pika populations are now, and will continue to look at connectivity after the crossing structures are built.

Pikas normally live in talus slopes, but also live in rock piles along the freeway and under the Gold Creek bridge. The team found six new pika sites in 2013 and surveyed a total of 57—41 of which were occupied. The team also discovered pikas living in alternative habitat—cottonwood stumps piled up near the Keechelus Dam. Pikas appear to readily colonize human-made rocky habitats in the I-90 area.

Museum exhibit

You can experience the researchers’ work first hand by visiting How did the Cougar Cross the Road? Restoring Wildlife Passages at Snoqualmie Pass, the latest exhibit at CWU’s Museum of Culture and Environment.

The brand new interactive exhibit tells the story of wildlife connectivity corridors linking animal populations formerly divided by Interstate 90. Follow in the footsteps of native fauna over a recreated wildlife overpass and discover how the cougar crosses the road, and how humans are helping.

For more information, go to www.cwu.edu/museum. The museum is on the first floor of Dean Hall. It is open 11 a.m.-4 p.m. Wednesday through Friday and 10 a.m.-3 p.m. Saturday.

Media contact: Barb Arnott, CWU Public Affairs, 509-963-2841, barnott@cwu.edu

March 18, 2014

PHOTO: Central Washington University biology professor Kris Ernest, center, works with her small mammal team in the Price Creek area adjacent to Interstate 90 in August 2013. The team's research is part of the ongoing I-90 wildlife monitoring project which will help guide the installation of wildlife crossing structures. (Rich Villacres/CWU)