There isn't a habitat or landscape that climate change hasn't already affected. From the boreal forests of Canada to the arid deserts of Arizona, species are adapting to shifts both subtle and substantial. Audubon's new climate report Survival by Degrees: 389 Birds Species on the Brink looks at the species within 12 different habitat types to gauge their level of risk if temperatures continue to climb. The report's findings are a wake-up call: As many as 389 out of 604 North American species face unlivable climate conditions if global temperatures hit 3 degrees Celsius above preindustrial levels.
And yet there is also hope in the report. By acting now, we can potentially help 290 bird species by keeping global temperatures below 1.5 degrees of warming. You can read more about the habitat groups, warming scenarios, and what species in your state are most at risk here, but for a quick preview of the report, here are five birds facing potential range loss—and how you can help them.
Tiny flames of orange amid dark spruce trees, Blackburnian Warblers are among the most colorful birds nesting in the boreal ecosystem. More than two dozen species of warblers breed in this vast northern forest. All move south in fall, but Blackburnians migrate farther than most, spending the winter mainly on the high, forested slopes of the Andes in South America. Some individuals make an annual round trip of more than 9,000 miles. During their spring and autumn journeys, Blackburnian Warblers pop up in woodlands and urban parks, delighting fresh-eyed and seasoned birders alike.
Outlook: Warming is likely to diminish the spruce forests favored by breeding Blackburnians—especially near its southern limits in the northeastern states and southern Canada. The warblers’ wintering range in the Andes is under threat, too, as loggers, miners, and farmers clear trees and contribute to habitat degradation. Because of their epic migration, these birds are also highly dependent on good stopover spots, which are becoming tougher to find as development continues to encroach.
Actions: As the Blackburnian’s breeding range creeps farther north from its wintering grounds, its average migration will become even longer. That makes it even more essential to protect and create stopover habitat, by planting native trees in communities along the birds’ path, for example. Campaigns to reduce building collisions and window strikes will also help warblers and other migrants. Several cities, such as Houston and Toledo, have recently adopted initiatives to turn off lights in tall city buildings on peak flight nights.
Before the first cool days of fall, flocks of Sanderlings are back on the beach, scooting along the sand’s edge as they chase the waves, snapping up tiny prey left behind by the receding water. These small pale sandpipers have come a long way from the high Arctic tundra, where they nest for a short spell in early summer. And many have a long way to go. Their winter range stretches from Alaska and northern Europe to the southernmost beaches of South America, Africa, Australia, and New Zealand.
Outlook: As the planet warms, much of Sanderlings’ coastal habitat is predicted to be engulfed by rising seas. Sanderlings typically gather on sloping sands, and while some beaches may migrate farther inland, that transition will occur more slowly than the birds need. Their Arctic breeding grounds, meanwhile, will experience severe warming, which could cause new plant growth to crowd the bare, open sites the birds prefer and diminish nearby surface water, rendering the land unsuitable.
Actions: Advocating for natural buffers rather than seawalls will make coasts more resilient to storms and sea-level rise, and beach stewards can provide Sanderlings with crucial protection from human disturbance while the birds are at the shore. Wiser marine-wildlife management would also give species a cushion: For example, Sanderlings feed on horseshoe crab eggs during spring migration, so protecting the arthropods may produce benefits up the food chain.
They’re the closest living relatives of the Great Auk, but unlike their extinct cousins, Razorbills can fly. This allows them to reach secure nesting sites on rocky islands around the North Atlantic, from Maine north to Labrador and Greenland, and in Iceland and northwestern Europe. Small flocks gather on the ocean surface over shoals and upwellings, slipping underwater to pursue schools of fish like herring, sandeels, and capelin. Then, like puffins, they wing back to feed their young with multiple fish lined up in their bills. In winter Razorbills disperse and some move south to the Middle Atlantic states, concentrated in waters over the continental shelf.
Outlook: Because their nests are so well hidden, it takes serious effort to census Razorbills. Gains in some areas, such as the Gulf of Maine, have been offset by losses elsewhere. Iceland, which hosts more than half the world’s breeding Razorbills, has seen a sharp decline since about 2005. That drop coincided with a crash in sandeels that was caused, some evidence suggests, by rising sea surface temperatures. So climate-driven changes to the food chain loom as a threat for these auks and many other birds that dwell in cold seas.
Actions: Taking steps to prevent deadly oil spills, including halting offshore drilling and tightening safety rules for tankers and pipelines, would help seabirds such as Razorbills. Because the birds become entangled in fishing nets as they swim and dive, keeping commercial fishing activities away from nesting colonies would also reduce accidental deaths. The Forage Fish Conservation Act, introduced in Congress this past spring, would help ensure they have food to catch by promoting better management of marine prey.
The rich, fluting songs of Wood Thrushes, which John James Audubon described as “the delightful music of this harbinger of day,” were once among the most familiar summer sounds in the eastern United States. These songbirds have become less common in recent decades, but they can still be found along streams and rivers, in deep forest interiors, and in some shady suburbs and large city parks, hunting for insects or feasting on small fruits. In fall the species migrates to grounds in southern Mexico and northern Central America, where solitary birds defend their understory territories.
Given their three-inch, feather-light bodies, Rufous Hummingbirds make an astounding journey, winging from wintering grounds in southern Mexico to nest as far north as Alaska. The tiny aerialists take an elliptical route that dovetails neatly with seasonal change: northwest through blooming deserts in early spring, southeast through lush mountain meadows in late summer. Hundreds of Rufous Hummingbirds, and other western hummingbird species, have also begun wintering in the southeastern United States, especially in lush urban gardens near cities like Baton Rouge.
Outlook: Rufous Hummingbirds seem able to adapt to a variety of habitats, including mature forest, patchy second-growth scrub, and even suburbs and city parks, as long as flowers are available. But the birds’ limits are not fully understood, and a warming climate may reduce their overall breeding range. What’s more, if shifts in temperature and precipitation trigger earlier blooms, they’ll throw off the birds’ precisely timed travels.
Actions: In keeping with their diminutive size, hummingbirds can be supported by habitat decisions on the smallest scale. Even a tiny yard or garden can be turned into a haven, providing these feathered gems with critical resources for survival. The ingredients should include a good mix of native plants that flower in different seasons, trees and shrubs for cover, and supplementary sugar-water feeders, especially in chilly weather. It’s also important to avoid use of pesticides, as hummingbirds eat many small insects as well.
This story originally ran in the Fall 2019 issue as “In Focus.” To receive our print magazine, become a member by making a donation today.