A volunteer holds a red-legged frog before gently placing it in the bucket to transport it across the many barriers, including Highway 30 and Harborton Road, between the breeding wetlands and upland forests (Courtesy of Leslie Bliss-Ketchum).
Why did the frog cross the road?
To get to the other side to mate and lay eggs. But the treacherous trip across two roads, a busy Highway 30 and two sets of railroad tracks can be fatal for the Northern red-legged frog, a species of greatest conservation need in Oregon. It's why volunteers have been shuttling the frogs back and forth between their home in Forest Park and their breeding site in the Harborton wetlands since 2014 — until a more sustainable, long-term solution can be found.
"Humans needing to move animals across the landscape means animals can't get there on their own anymore," said Leslie Bliss-Ketchum '07 PhD '19. "That's a symptom of a disease we're trying to correct for."
Bliss-Ketchum, who is now founder and owner of environmental consulting firm Samara Group, is part of a collaborative group of PSU researchers, government officials and others hoping to improve wildlife connectivity across Oregon, one of the state's key conservation issues. Many species rely on the ability to move throughout 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 Oregon Department of Fish & Wildlife, brings together ecologists, GIS analysts and statisticians to analyze and map the habitat and movement needs of nearly 60 species ranging from as small as a bee to as large as a bighorn sheep and elk. The species are surrogates for a broad diversity of species across the state and their habitat needs and movement abilities. A beaver, for example, stands in for species that require riparian habitat.
"While there are instances throughout the state of groups or efforts that have identified connectivity needs for individual species or local areas, we lack information more broadly throughout the state of Oregon on where wildlife connectivity is intact, where it's functioning but threatened and where it's been cut off completely and needs to be restored," said Rachel Wheat, wildlife connectivity coordinator at ODFW and the project's lead.
Using new approaches and state-of-the-art modeling, the group is turning raw data into a usable map of priority wildlife corridors that can then be used by state and federal agencies, conservation groups and others to inform land use development and permitting for renewable energy projects, target areas in need of restoration and protection, and 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 — make it great for people and great for animals," de Rivera said.
The timing of the project, which is also supported by the U.S. Fish and Wildlife Service and the Oregon Department of Transportation, could not have come at a better time. For the first time, Congress has made a major investment in wildlife crossings, allocating $350 million in the recently passed infrastructure package 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 in the state.
Bliss-Ketchum, whose dissertation research at PSU focused on issues of urban wildlife, habitat connectivity planning and roads as barriers to wildlife movement, credited the collective expertise of the project team with moving an undertaking of this magnitude forward.
Her firm led the process for selecting the 54 representative species with input from biologists, conservation planners, species experts and potential end users of the connectivity maps.
Geography professor Martin Lafrenz and Amanda Temple MS '20, project associate with Samara Group, then worked together to combine GIS data with expert knowledge of a particular species' needs (i.e. the animal requires wetland habitat, will not travel further than 500 meters from a water source) to build habitat permeability models. These models highlight a species' primary habitat needs and the landscape features that make it easier or more difficult for them to move.
But the models are considered only a hypothesis until validated. That's where statistics professor Daniel Taylor-Rodriguez and Ph.D. student Jacob Schultz come in, cross-checking the habitat permeability models against data of species' actual observed movement and presence — something that hasn't been done on this scale before.
Two of Lafrenz's geography graduate students — Lauren McKinney-Wise and Claire Brumbaugh-Smith — then create the habitat connectivity maps using new software from The Nature Conservancy, which are again validated.
"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.
Wheat said the map will be updated every five years to stay current with the changing landscape, climate and data.
"Development is never-ending," she 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."
Other project partners include: Andrea Hanson from the Oregon Department of Fish and Wildlife and Alana Simmons '18 MS '21, a subcontractor for Samara Group.
Take a deeper dive into the project with Rachel Wheat, wildlife connectivity coordinator for Oregon Department of Fish & Wildlife