The fading miracle of migration

Photo courtesy of Pepper Trail
This fall in Ashland, Ore. Snow geese migrating nearby.

by Pepper Trail | PREVIEW Columnist

For the past few weeks, dozens of turkeys have been circling the thermals over my home in Oregon, preparing to fly south to California. Not long ago, I saw a late monarch butterfly fly overhead, its orange wings glowing against the blue sky.

These are examples of the great migrations that enliven the West each spring and fall.

The seemingly fragile long-distance migrations of monarch butterflies are among nature’s most incredible phenomena, with eastern populations wintering in large numbers in a small refuge in Mexico and western populations in several refuges along the California coast.

Migration plays a central role in the lives of many wild animals of great public interest and economic importance, from salmon to waterfowl. Almost everyone attuned to the natural world looks forward to some phase of migration, whether it’s the arrival of spring’s first crow or the start of duck hunting season.

Thanks to advances in technology and data collection, this is a golden age for migration research. Radar makes it possible to document the magnitude of animals in motion: For example, there were an estimated 5.4 million birds in the skies over Oregon on a recent night.

The citizen science database eBird has provided migration maps with amazing specificity, along with advances that allow the detection of signals from light tags attached to migrating animals. Visit https://tinyurl.com/mtndawtm for an example with turkeys.

At the same time, we also understand the many threats to migration. The precipitous decline of Pacific salmon is well known. Elk and pronghorn face increasing obstacles from highways, fossil fuel access and removal roads, and other developments on the landscape.

But what happens to the migratory birds really tells the story. Based on multiple lines of evidence, scientists have concluded that 2.9 billion — yes, billion — breeding adult birds have disappeared in the United States since the 1970s. That’s one-third of the total bird population in the United States.

Of those 2.9 billion, 86 percent, 2.5 billion are migratory species. Although bird declines in the western part of the country are generally less severe than in the East, many of our familiar migrants are showing sharp declines, including a 60 percent decline in the dusky hummingbird; common nightbird, 58 percent; band-tailed pigeon, 57 percent; Lewis’s woodpecker, 67 percent; and evening grosbeak, 92 percent.

Why does this happen? Habitat loss is a major problem for many species, especially grassland birds. For example, between 2018 and 2019 alone, 2.6 million acres of grasslands were converted to row crops in the Great Plains. This is a larger area than Yellowstone National Park. Loss of winter habitat in Mexico and Central America also threatens many species.

From power lines to wind turbines to oil wells, human constructions increase migratory threats to birds. The biggest threat may seem mundane, but it’s everywhere: windows. Collisions with windows are estimated to kill billions of birds in this country every year. Brightly lit skyscrapers are also a threat to migrating songbirds at night.

Climate change increases threats to migratory species. In addition to widespread impacts such as widespread drought in the West and melting permafrost in the Arctic, climate change may disrupt the relationship between migration timing and food availability. Hungry migrants may arrive in spring to find that the peak of insect abundance has already passed.

Fortunately, there are many things each of us can do to help migratory birds. First, advocate for the preservation of bird habitat – and support yourself by planting native fruit and flowering plants on your own land.

Second, take steps to reduce bird collisions with your windows. Many solutions are available, including “Zen wind curtains”: light cords suspended in front of the glass. Visit https://tinyurl.com/2hf558nj for DIY instructions and lots of other information. And keep your cats inside, because free-roaming cats can wreak havoc on birds.

Finally, support organizations that protect birds and their habitats or promote migratory bird research, such as the National Audubon Society, the American Bird Conservancy, and the Cornell Laboratory of Ornithology.

Together, we can save the lives of millions of birds and help their incredible migratory journeys never end.

Pepper Trail is a contributor to Writers on the Range for writersontherange.org, an independent nonprofit dedicated to fostering lively conversations about the West. He is a naturalist and writer in Oregon. The views expressed do not necessarily reflect the views of SUN.

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