Study finds climate change affects birds’ migratory patterns

Birds have held a special place in professor Allen Hurlbert’s heart since he first began researching hummingbirds as an undergraduate.

The birds he studies in North Carolina are more common than the tropical birds he has studied in the past, but Hurlbert said the field is still compelling.

“There is color if you know where to look,” he said.

For Hurlbert, that color has recently amounted to a study indicating that climate change is influencing the migratory patterns of birds in the eastern United States.

The study was published Wednesday in the journal PLoS ONE, and is titled “Spatiotemporal Variation in Avian Migration Phenology: Citizen Science Reveals Effects of Climate Change.”

Co-authored by former undergraduate student Zhongfei Liang, the study also indicates that birds that are less able to adapt could see population decline.

Hurlbert said if the trend continues and species fail to adapt, their populations could decrease more drastically.

Liang said it was migratory birds’ tenacity that first drew her to undertake the study with Hurlbert.

“Birds, especially ones that migrate, have so much going against them,” Liang said. “It is definitely a fight for them, but they keep on going.”

UNC biology professor emeritus Haven Wiley said it is because birds’ behaviors are unpredictable that people want to study them.

“Because they can fly, almost any bird could potentially occur almost anywhere,” he said. “So it is fun to see which species are in the neighborhood at any one time.”

Recently in Coker Arboretum, amateur birder and biology student Elle Law discovered a hummingbird more than 3,000 miles from its intended migratory destination of Mexico.

The discovery of a bird not indigenous to the East Coast is the sort of find that motivates bird watchers to continue sharing their observations, she said.

It is birdwatcher’s fastidious attention to detail and meticulous record keeping that enabled the study, Hurlbert said.

The data Liang and Hurlbert analyzed was compiled by over 35,000 contributors on the website eBird.

While initially the online database was intended to be used by fellow birdwatchers, Hurlbert said in the last couple of years, scientists have begun analyzing that information.

The volume of data enabled Liang and Hurlbert to analyze climate change’s effects on animal behavior in a way that isn’t possible for other species.

“In one sense, we can view birds as canaries in the coal mine … for most other groups of organisms, we don’t have the data out there to even ask these questions,” Hurlbert said.

“It is potentially cause for concern.”

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