Winging It through a Warming World
- 5 days ago
- 6 min read
How Climate Change Is Disrupting Bird Migration Routes, Timing, and Survival
Every spring and fall, billions of birds embark on one of nature's most remarkable journeys. Tiny songbirds cross continents, shorebirds traverse oceans, and raptors ride invisible currents over mountains and deserts. For countless generations, these migrations have followed seasonal rhythms that evolved over millennia. Today, however, those rhythms are changing.
Climate change is altering temperatures, weather patterns, and ecological cycles around the globe. For migratory birds, whose survival depends on arriving at the right place at precisely the right time, even subtle environmental shifts can create profound challenges.
“Birds have very long and complex life cycles, and [climate change] impacts all of that," says Dr. Morgan Tingley, professor of ecology and evolutionary biology at the University of California, Los Angeles. "I study how climate change is impacting birds throughout their lives."
According to Tingley, changes in the global environment are likely affecting migration timing, migration routes, breeding success, and even food availability throughout birds' annual cycles.
Racing against an Earlier Spring
One of the most significant challenges facing migratory birds is timing.
Across much of North America, spring is arriving earlier than it once did. Warmer temperatures cause trees to leaf out sooner, flowers to bloom earlier, and insects to emerge weeks ahead of historical schedules.
Across much of North America, spring is arriving earlier than it once did.
For migratory birds, this creates a problem, according to scientists who studied the matching of spring “green-up” periods with migratory timing.
Birds innately seek to migrate to coincide with seasonal abundance. When they arrive on their breeding grounds, they must quickly establish territories, build nests, lay eggs, and raise their young while food supplies are at their peak.
“Birds are trying to time the migration of when they arrive on their breeding grounds, and therefore timing when they create their nests and when they lay their eggs, to specifically the right time of year for when there's going to be the biggest seasonal availability of food,” Tingley explains.
When climate change shifts spring conditions earlier, birds may arrive after that peaking has already begun. Scientists refer to this phenomenon as a “phenological mismatch”—a disconnect between biological events that historically occurred in synchrony.
“So maybe every year, the leaves are coming out a little bit earlier and it's getting warmer a little earlier,” Tingley says. “And that can cause real problems for birds because it could mean that when birds actually arrive on their breeding grounds, that they're just a little behind where spring actually is.”
Even a small mismatch can have consequences. If fewer insects are available when chicks hatch, this may impact survival rates and breeding success.
Why Long-Distance Migrants Face Greater Risks
Not all birds experience climate change in the same way.
According to Tingley, approximately 70% of bird species found in the United States are migratory. Some travel only short distances between seasonal habitats. Others undertake astonishing journeys spanning entire hemispheres.
Approximately 70% of bird species found in the United States are migratory.
The lengths of these journeys matter.
Birds that winter relatively close to their breeding grounds are likely to experience similar weather patterns throughout their migration route. Thus, if spring arrives early in one area, it is likely to come early in nearby areas too.
But long-distance migrants do not have such an advantage.
“The birds that migrate the farthest … are the ones that are honestly having the hardest trouble keeping up with climate change,” says Tingley.
“If you're a bird that is living in Argentina and then migrating all the way back to New York in the springtime, those temperatures and those seasons are going to be very disconnected from each other,” Tingley explains. “So a bird in Argentina might not actually have the information it needs to arrive on time and keep up with climate change that's happening in New York.”
As climates shift more rapidly, this disconnect may make it increasingly difficult for some species to synchronize migration with favorable breeding conditions.
More Than a Timing Problem
Climate change affects birds in ways that extend beyond migration schedules.
As temperatures rise, many species are shifting their geographic ranges in search of suitable habitat. Scientists have documented birds moving northward and to higher elevations as they track cooler conditions.
As temperatures rise, many species are shifting their geographic ranges in search of suitable habitat.
At the same time, habitats critical to migration are changing. Wetlands, coastal marshes, and stopover sites provide food and shelter for birds undertaking long journeys. Drought, land-use change, and rising sea levels threaten many of these habitats.
Extreme weather events create additional hazards.
Heat waves, hurricanes, severe storms, droughts, and wildfires can destroy habitat or force birds to alter migration routes. Wildfire smoke alone can affect air quality across vast regions, causing birds to expend more energy as they navigate around dangerous conditions.
For species already coping with habitat loss and other environmental pressures, climate change acts as an additional stressor.
“When birds become … mismatched with climate and seasonality, it could mean that, essentially, populations decline,” Tingley says. “And already in North America we've been having a lot of bird populations declining over the last 40 years.”
Climate change, he adds, can compound those existing declines.
Why Birds Matter
Bird migration is one of the natural world's great wonders, but its importance extends beyond its beauty.
Birds play critical ecological roles. Many species consume insects that damage crops and forests. Others pollinate plants, disperse seeds, and contribute to healthy ecosystems. Their presence often serves as an indicator of environmental health.
Tingley notes that people's connection to birds can also be deeply personal.
Tingley notes that people's connection to birds can also be deeply personal.
“For me, I've grown up just caring about nature and loving birds,” he says. “Bird watching is actually one of the fastest-growing hobbies in the United States … a lot of people [watch for] a specific bird or bird population.”
For many people, the songs of birds signal changing seasons, connect them with the natural world, and bring great pleasure. A decline in bird populations represents not only an ecological loss but also a cultural and emotional one.
“When we have decreased bird populations, it also means that our environment is just not going to work as well,” Tingley says. “That could mean that we have a lot of problems and can cause issues for things like food supply.”
Supporting Birds in a Changing Climate
Although the challenges are significant, scientists emphasize that actions taken today can help migratory birds adapt to a warming world.
Protecting wetlands, conserving habitat, reducing pollution, and limiting other human-caused threats can strengthen bird populations and improve resilience. These traditional conservation measures remain among the most effective tools available.
“Climate change is kind of like the stressor that is being added on top of everything else going on in the environment,” Tingley says.
Because many of the most severe impacts of climate change lie in the future, conservation efforts undertaken now may help sustain bird populations through the decades ahead.
As spring migration reaches its peak each year, Tingley encourages people to step outside and experience it firsthand.
“If you are someone who has never actually gone bird watching,” he says, “this is the time.”
Watching a flock of birds cross the sky can inspire wonder. It can also serve as a reminder that Earth's ecosystems are deeply interconnected. A warming climate in one region can affect breeding success thousands of miles away, linking distant landscapes through the journeys of migratory birds.
Their migrations reveal both the resilience and vulnerability of the natural world—and remind us that stewardship of the planet is a responsibility shared across continents, generations, and species.
*Francesca Bell is a writer, editor, coach, and consultant with a passion for helping people communicate their ideas, stories, and experiences effectively. In addition to her editorial and consulting work, she writes fiction across multiple genres and is the founder of Bell Literary Services. To read her fiction, please visit her Substack at: https://franbwriting.substack.com/. To connect with her regarding any book projects or for coaching and consulting services, visit her website: https://www.bell-literary-services.com/.
Sources
SciLine. "Bird Migration and Climate Change: Interview with Dr. Morgan Tingley." April 29, 2026.
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