Eyewitness to spring migration in the Gorge

Because good foraging habitat is important for these hungry migrants on their energy-intensive journeys, finding them requires looking in the right place. The first arrivals local birder Miko Ruhlen notices are orange Rufous Hummingbirds buzzing her hummingbird feeder.

Ruhlen, a former field biologist with the Point Reyes Bird Observatory in California, is also involved in Klickitat County migration surveys.

Along the Columbia, “waves” of shorebirds pause to rest and refuel — everything from common Western and Least sandpipers to unusual phalaropes and plovers, foraging like maniacs. “Imagine you were on a really long hike or something and you just hiked 100 miles and you stop and eat something,” said Ruhlen.

Songbirds and raptors start arriving in February and March. “People are always really happy to see warblers because they’re really pretty,” Ruhlen said, noting spring migration is one of the best times for Gorge birdwatching, as migrants in brilliant breeding plumage sing on their way north; rare birds stray through; and wildflowers bloom. Ruhlen recommended binoculars and the free Merlin Bird ID app from Cornell University, which uses artificial intelligence to help identify photos and sounds, and questionnaires to narrow down possibilities.

“Migratory birds tend to follow river corridors,” Terrill said. “Like riparian stretches with willows, cottonwoods, older stuff like that tend to be good ... Most of the time, when birds are migrating during spring, they get up at dusk, and they fly high in the sky at night, and then they land again at dawn.”

However, the loss of almost three billion birds from the U.S. since 1970 begs a question — in 50 years, will spring migration still bring a 100 species past the Gorge?

Terrill provided a big-picture view. “Habitat change is probably the biggest change, birds use stopover habitat for refueling,” he said. “When riparian habitat and things like oaks are lost, that tends to have a bigger effect on migratory birds.” The loss of river corridors and riparian habitat to dams, and land use change like development over the past few centuries, has likely significantly changed the migrations that now pass through the Columbia River Gorge, Terrill admitted.

Climate change has also made the timing of migration a keen interest for scientists, he added. Migration routes have evolved over millions of years to bring birds to breeding grounds at a date when spring temperatures and available food allow them to raise nestlings. But now spring’s getting earlier, and warmer, and their timing is off.

Scientists have evidence that some birds adapt — and some don’t, Terrill said.

It is, in a word, complicated. “Habitat is being lost as the climate is changing,” Terrill explained. Disentangling these factors is hard. And ecosystems have always sustained cycles of disturbance. “There might be a landslide or a fire ... new growth comes in, and there’s birds associated with that new growth,” said Terrill. “And that turns to older growth ... there are these sort of cycles of birds, species coming and going on smaller, smallish scales, when the issue is that the scales are changing, the scales are getting a lot bigger.”

Fire and disturbance are important dynamics of healthy ecosystems, but at times, small remaining fragments of habitat can no longer sustain the cycles, Terrill explained, while wildfires and storms increase in severity.

Disturbances to stopover habitat can be critical, such as dogs chasing sandpipers on Columbia beaches. Migrants become too disturbed and exhausted to find the food they need. “They just need to eat and rest and it’s hard when they’re getting constantly flushed. So giving them space and letting them rest and eat is, I think, a great way you can help,” Ruhlen added.

Songbirds help trees by eating caterpillars and other pests, she said, but migrants are vulnerable to pesticide usage, and the cutting of trees; they die trying to fly through windows; they become disoriented by artificial light on their night-time flights, normally guided by the faint natural light the stars.

Ruhlen’s solutions include decorating windows with decals to repel birds, and cutting outdoor lights when Bird Alliance of Oregon posts predictions for high numbers of night-flying migrants on social media.

With the rapid advance of technology, scientists have more tools to study flyways, important habitats, and sources of migrant mortality. Feathers and blood, fecal material and environmental DNA are analyzed, migrants tracked via Doppler radar, tagged and tracked by satellite, and counted by artificial intelligence as they fly across the moon. An international network of MOTUS towers picks up signals from transmitters so small and light, songbirds and even dragonflies can be tagged with them. And the citizen science platform eBird logs about two million sightings annually.

“We tend to always think it’s only what we do here,” said Ruhlen. But many birds are impacted on South American wintering areas, and migration stopovers. “They’re all important. So, you might want to buy bird-friendly coffee or ... help conserve forest. And not only here, but also in ... South America, because they don’t stay here year round.”

Terrill finds hope in the work of conservation nonprofits, he said. “There are some encouraging things, there are groups that get together and are interested in helping bird populations, and there are bird populations that have been shown to have stabilized and rebounded,” he said. “There are federal entities which have interest ... So it’s not all doom and gloom.”

Ruhlen, however, noted that protecting migrants in stopover habitat also rests with individual citizens.

“After spending over a decade immersed in watching birds in their native habitats, I have come to the view that ‘our’ beaches, lakes, ponds, rivers, forests, and other natural areas are not ‘our’ playgrounds just for human recreation pleasure,” she said. “Migrating and nesting birds rely on these places to for food, water, shelter, and rest during long-flight migration, to stay alive and to continue their species. If we want to continue to receive the benefits of birds, not only their beauty and songs, but their benefit to our world such as eating mosquitoes and other insects and keeping forests alive eating caterpillars, spreading seeds and pollen, and doing their part for the food web, we need to share the natural areas and treat them as important habitat. This includes our backyards, too.”

Everyone seems to agree that even for non-biologists, migration can be just plain fun. “For the general public migration is a really cool phenomenon, billions of birds every year fly hundreds or thousands of miles,” Terrill said. “... This little bird, that weighs less than a nickel, coming back to breed in your yard for the tenth year after flying 5,000 miles every single year.”