In June 2021, a devastating heat wave scorched the Pacific Northwest, with temperatures soaring from 108° to 121°F. In Central Oregon, Pelton Dam on the Deschutes River reached 119°F. The impact devastated wildlife, with birds among the hardest hit. Babies leaped from nests in droves, overwhelming wildlife rehabilitation centers across the region.
As climate patterns shift, birds across North America face challenges reshaping their lives in both subtle and dramatic ways. The rhythms of nature that birds have relied on for millennia are changing, creating new challenges for species already navigating a complex world.
The National Audubon Society’s “Survival by Degrees” report for Oregon and the Oregon Department of Fish and Wildlife’s “Conservation Strategy” document ecological effects that will permanently alter Oregon’s landscapes and wildlife. Rising temperatures, altered precipitation patterns, drought and extreme weather events are expected to change habitats and ecosystems throughout Oregon. Over the next century, our conifer forests — currently covering half the state — could dramatically decline while shrublands and grasslands expand.
The just-released State of the Birds report for 2025 by the North American Bird Conservation Initiative (NABCI) — a consortium of scientists and agency experts — states that “more than one-third of U.S. bird species are of high or moderate conservation concern.” Notably, aerial insectivores, like nighthawks, swifts and swallows, top the list for being extremely vulnerable to these life-altering ecosystem shifts. Other terrestrial birds, like our western forest birds, are also in particular trouble. Arid and grassland birds, shorebirds, seabirds and non-waterfowl waterbirds are already experiencing substantial declines. All will be forced to adapt, move or perish.
In Central Oregon, our feathered neighbors face unprecedented challenges in an arid landscape already altered by humans. Let’s explore how we can help.
It’s All About Time
Birds evolved precise timing for their life cycles and migrations. For many species, spring migration and breeding coincide with the explosion of insects that follows the seasonal flush of new leaves. This abundance of protein-rich food is essential for successfully raising young. Across much of North America, early springs can cause birds to miss times of peak food abundance. This timing mismatch lowers survival rates for nestlings and adults, and can lead to declining bird populations.
While overwintering birds experience these early warming trends and sometimes adjust, birds wintering in Central or South America can’t detect these changes from thousands of miles away. They rely on daylight length, internal biological clocks, instinct and other cues to time their journeys north. Some migrating birds try to adapt by rushing through migrations and skipping rest periods. It’s like running a marathon and immediately starting another race. Upon arrival, they might urgently begin breeding, leading to poor body condition and higher nestling mortality.
In Central Oregon, jump-started springs “snowmageddons” transform into prolonged cold and rainy periods that last until the weather decides it’s summer sometime in June. Birds tricked into nesting earlier face cold periods that force birds to sacrifice feeding time to keep eggs or babies warm. Breeding season cold snaps and heat waves reduce nest success for most North American bird species.
Disappearing Dinner
If you see fewer bugs splattered on your windshield, you’re witnessing a troubling trend. Insect populations are declining worldwide, with some studies showing drops of 75% in certain regions and a 40% decline globally. Climate change contributes to this decline, alongside habitat loss, drought and pesticide use. Research shows insect loss most severely impacts avian terrestrial insectivores.
About 96% of North American terrestrial birds feed their young on insects. Climate-driven and human-caused insect declines create a perfect storm, threatening insect-eating birds and their young. Bird parents bring their chicks thousands of insects; juicy, fat caterpillars are a favorite. Carolina chickadees, for example, plump up hungry nestlings with 6,000 to 9,000 caterpillars in a season. Aerial insectivores like tree swallows and bluebirds collect even more of flighted insects.
The relationship between temperature and insect availability is critical. When temperatures drop below certain thresholds, insects become inactive, making them unavailable to birds regardless of actual abundance. Birds breeding to match earlier spring temperatures face twice the risk of encountering deadly cold snaps that drastically reduce insects. A single cold snap during breeding season can reduce bird offspring survival by more than 50% in some species. Extreme heat can also destroy insects or send them into hiding.
Mid-winter “false springs” — warm, spring-like days — also threaten insect populations as they can trick insects into emerging from hibernation or hatching early. When freezing temperatures return, they face starvation, predation and death. Repeated fluctuations between hot and cold can create local insect depletions, especially during drought.
Habitat Loss from All Angles
Climate change doesn’t act alone. It compounds other threats like habitat loss, wildfire and urbanization. The way we respond to these challenges affects birds in profound ways. Conversions of native plant communities to nonnative landscaping, agriculture and urban development dramatically reduce suitable habitats for many bird species. It also results in insect declines.
Doug Tallamy, in 2009, reported that “even centuries after their introduction, nonnative plants support on average 72% fewer insects.” No matter how lush it appears, a yard filled with nonnative plants can become a food desert for birds. Birds rely on our native shrubs, including sagebrush and rabbitbrush, and other local plants for food and nesting sites. Sadly, homeowners are being required to remove native shrubs for fire prevention.
Forest management can have unintended consequences, notably when urbanization is already eliminating substantial habitats. Logging and thinning projects designed to reduce fire risk often space out tree canopies, exposing forest floors to more sunlight and drying out soils that once retained moisture. Management practices that mow native plant understory alter the entire ecosystem biome. Yet, there are ways to mitigate fire risk and preserve native habitats.
Drought exacerbates all of these challenges. Water scarcity affects plants, limiting the production of seeds and leaves that sustain plant-eating birds. It also reduces insect numbers, creating ripple effects throughout the food chain.
We Can Help
Baby birds face a gauntlet of life-threatening challenges. Climate change exacerbates these risks. Mortality rates in most baby birds are high. For instance, 75% of young robins and bluebirds do not survive until winter. These statistics are common for many songbird species. Predators cause the most mortality of nestlings and fledglings, both in the nest and out. Unfortunately, human-altered landscapes increase predator — birds and mammal — populations. Outdoor cats, windows, weather and habitat loss also take a substantial toll.
Wild birds are indicators of broader ecological shifts that eventually affect us all.
Working to protect and restore our native ecosystems is key to supporting our flighted friends. The more native wildflowers, shrubs, trees and other plants we preserve in their natural landscapes, the more bird populations are saved. Being an advocate and voice for our indigenous plant communities, both in the urban landscape and in our public lands, is critical.
Gardening for wildlife is a great solution, provided we offer safe habitats free of threats, like windows and cats. Planting regional native plants (from native plant nurseries) that support the adult stages of insects and juveniles can fill ecological gaps. Encouragingly, new research is exploring how native plant-based cultivars (slightly adapted versions of indigenous plants) might offer alternatives to hard-to-find or at-risk regional indigenous plants.
Along with native plant gardening, we can make enormous contributions by protecting birds from window collisions and cats. Residential windows kill up to 500 million birds annually; large buildings up to 500 million more. Keeping cats indoors and avoiding pesticides will save billions of birds as well. We can enjoy our flighted visitors so much more when we have done all we can to ensure their safety.
Birds adapt, but the rapid pace of change may exceed their ability to adjust. Our choices will determine which species thrive, struggle or disappear. By understanding these challenges, we can take meaningful action to help birds navigate a changing world.
—Elise Wolf directs Native Bird Care, an avian rescue (nativebirdcare.org)
This article appears in The Source Weekly March 20, 2025.
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