Canary in the Coal Mine? What Bird Die-Offs Signal About the State of Our Climate
"Birds" by Phil Fiddyment is licensed under CC BY 2.0
Andie Hall
This fall, the Western U.S. saw an unprecedented—and currently inexplicable—massive bird die-off. Two coinciding events are top suspects for potential explanations: an early cold snap and record-breaking wildfires.
Smoke from the wildfires in California and across the Western coast caused significant changes in air quality and even a temperature drop in some areas of the United States. Residents in Seattle noticed stressed and abnormal behavior from birds this summer when there was so much smoke that the air became cooler. In the Southwest, hundreds of birds were found dead across the state of New Mexico. Scientists and ornithology students immediately began to investigate and found that many of the birds were malnourished with evidence of smoke inhalation. A cold snap following a prolonged drought in the Southwest caused scant food supplies while unprecedented wildfires created additional challenges.
The hot weather from this summer was undoubtedly a major factor in the historic fires across the West. This summer was the fourth hottest and among the driest one-third of all summers on record. Unsurprisingly, when there is a fire in birds’ habitats, they fly away. But what happens when there are fires across their migratory paths, or so many fires that they have fewer habitat replacement options? This summer, fires and thick smoke blanketed most of the West, so even if birds flew away from their normal habitat, they likely ran into similar issues wherever they went. Some scientists believe that even when birds attempt to flee, smoke inhalation makes it more difficult to escape the area. Further, fires across the states not only affected the food supply itself, but also the birds’ ability to obtain it due to the respiratory effects of smoke inhalation.
While this is a largely unprecedented event in the United States, massive fires in Asia presented a learning opportunity for researchers in 2015. There, scientists were able to measure bird activity in air quality risk areas. They found that birds were active and able to forage for food when the air quality was good, but were essentially inactive when air quality was poor. The study theorizes that high Asian bird mortality may have resulted from lower fitness, diminished foraging success, and reduced food sources as a result of poor air quality. Perhaps this explains the stressed bird behavior in Seattle and malnourishment in New Mexico.
While large numbers of deceased birds appeared earlier this fall, an early cold front that swept across the Rocky Mountains created a perfect storm. A few inches of snow and a massive drop in temperatures resulted in another wave of unsurmountable challenges for our Western birds. In Early September, hundreds of birds descended on Gore Creek in Vail exhibiting similar stressed behavior to those in Seattle and later succumbed to the low temperatures. Birds, already weak from the smoke and habitat changes, were forced to face low temperatures in normally warm parts of their migration paths.
While the cause of the bird deaths is still being investigated, many researchers and experts hypothesize that this is illustrative of a bigger issue: climate change. New weather patterns can create more fuel for fires. For example, heavy Californian rains in 2017 caused extraordinary plant growth, but that lush growth quickly turned into tinder following record heat and drought the following summer. While the climate itself does not cause an individual lightning strike to ignite a fire, it may create ideal conditions for larger, more intense fires. Changing weather patterns also affect birds in an immediate sense: the unexpected cold snaps in early September are generally uncharacteristic of our Western weather.
While the official determination of these mass bird die-offs is yet to be announced, current hypotheses can easily lead to the thought that they are the canary in the coal mine for the future of our climate.