Tracks like these help researchers map habitat needs and potential obstacles. Photo by So-Min Kang.
Why did the frog cross the road? To get to the other side, of course, so it could mate and lay eggs. But the treacherous trip across two roads, busy Highway 30, and two sets of railroad tracks can be fatal for the northern red-legged frog, which is endangered in Oregon. That’s why volunteers with the Harborton Frog Shuttle have been scooping up the frogs and transporting them back and forth between Portland’s Forest Park and their winter breeding site in the Harborton wetlands since 2014, until a more sustainable, long-term solution can be found.
That humans must venture out at night with buckets and flashlights to disrupt this real-life game of Frogger is “a symptom of a disease we’re trying to correct for,” said Leslie Bliss-Ketchum ’07 PhD ’19, founder and owner of environmental consulting firm Samara Group. She’s part of a collaborative group of PSU researchers, government officials, and others hoping to improve wildlife connectivity, one of the state’s key conservation issues according to the Oregon Department of Fish and Wildlife (ODFW). Many species rely on the ability to roam through the landscape to successfully find food, water, shelter, and mates, but barriers like roads, buildings, railroads, and power lines often restrict their movement.
“Connectivity is really vital for the functional ecosystems that we depend on,” said Catherine de Rivera, professor of environmental science and management and PSU’s lead on the project. “Where we see fragmentation and barriers to connectivity, we see inbreeding and a decrease in population size and stability.”
The Oregon Connectivity Assessment and Mapping Project, led by ODFW, has brought together ecologists, geographic information systems (GIS) analysts, and
statisticians to analyze and map the movement needs of 54 species ranging from as small as a bee to as large as a bighorn sheep and elk. The animals serve as surrogates for a broad diversity of species across the state, as well as their habitat needs and movement abilities. A beaver, for example, stands in for multiple species that require habitat along the banks of rivers.
Cut off from their breeding grounds, endangered red-legged frogs are collected by hand. Submitted by Leslie Bliss-Ketchum.While individual groups and efforts like the Harborton Frog Shuttle have identified connectivity needs for individual species or local areas, there hasn’t been information for the state more broadly, said Rachel Wheat, wildlife connectivity coordinator at ODFW and the project’s lead. The group aims to change that.
Using new approaches and state-of-the-art modeling, the group has turned raw data into a usable map of priority wildlife corridors. Once completed, it can be used by state and federal agencies, conservation groups, and others to target areas in need of restoration and protection, to inform land use and permitting for renewable energy projects, and to help prevent wildlife-vehicle collisions.
For example, the map could help identify where in the state limited resources would best be spent on building or improving wildlife crossings—culverts and bridges designed to help animals safely move between habitats—or where best to build a new road.
“I really see this project mandate as a realization from the state that we can work together across all sectors to maintain what
we love about Oregon,” de Rivera said, “[making the state] great for people and great for animals.”
The timing couldn’t be better. Congress made a major investment in wildlife crossings in the recently passed infrastructure package, allocating $350 million for a Wildlife Crossing Pilot Program that will help fund projects in all 50 states. Similarly, the Oregon Legislature approved $7 million in funding for building and maintaining wildlife crossings.
Bliss-Ketchum’s firm led the process of selecting the representative species for the mapping project. Martin Lafrenz, geography faculty, and Amanda Temple MS ’20, a project associate with Samara Group, then worked together to combine GIS data with expert knowledge of a particular species’ habitat requirements (for example, if an animal will not travel further than 500 meters from a water source) to build models that highlight a species’ habitat needs and the landscape features that make it easier or harder for them to move.
The models are considered hypothetical until validated. That’s where statistics professor Daniel Taylor-Rodriguez and Ph.D. student Jacob Schultz come in, cross-checking the habitat models against data of a species’ actual observed movement and presence—something that hasn’t been done on this scale before.
Two of Lafrenz’s geography graduate students then create the habitat connectivity
maps using new software from The Nature Conservancy. These maps are validated, too.
“We’re interested in modeling not only where the species is, but where it could be and what’s better for that species’ movement,” Taylor-Rodriguez said.
The 54 single-species maps will then be combined into one composite map that highlights priority wildlife corridors and represents movement needs for all wildlife in Oregon. The map will be updated every five years to stay current with the changing landscape, climate, and data.
“Development is never-ending,” Wheat said. “We expect to see expansion of urban growth boundaries, new solar facilities, new commercial development, new resource extraction, new wildfires… That will all be taken into consideration to make this a living product that changes as the landscape changes.”
As for the frogs, the long-term goal is to create pond habitat west of Highway 30 to support their needs. Until then, Frog Shuttle volunteers are doing everything they can to keep them hopping.