As I write this I am watching the smoke from the Camp Fire, the largest fire in California history. I am only a few miles away, upwind and in no danger, but the sight is rather intimidating.
Migration time is here and I have for decades watched ducks, geese and swans pass over my house enroute to the nearby wildlife refuges for their winter respite. But now they encounter large blankets of smoke. The north edge of the smoke is over my house and as the waterfowl encounter it, they seem confused. Usually they pass over in a straight line, headed in a specific direction. Now they turn, and turn again, and sometimes circle before moving on.
Birds navigate using a number of clues: the sun, the moon, the stars, landmarks, geomagnetic lines of force, and perhaps infrasound. Under a layer of smoke, the easiest clues to use, the celestial bodies and landmarks are obscured or not visible at all.
Clouds are always a possibility for the birds, but the birds can fly through the clouds or over them and continue on their way. No so with smoke. Smoke is a mixture of gases and fine particles In addition to irritating eyes, these fine particles and gases can be inhaled deep into the lungs. Wildfire smoke contains carbon monoxide, a colorless, odorless and toxic gas. Birds, due to their unique respiratory system are more sensitive to the effects of carbon monoxide than other animals are. Compared to mammals, more oxygen is transferred into the blood with each breath. This is why canaries were historically used in coal mines to warn for the presence of carbon monoxide and other noxious gases. Audubon has an article explaining in more detail how air pollution affects birds.
The Camp Fire (so called because it started near Camp Creek, not because it was started by a campfire) is moving so fast that it ignites a football-sized area of woodland every second. Another estimate was is that it was moving at 18 miles per hour. A dangerous, fast fire.
Fire has been around forever and many plants and animals have evolved with it. Wildfires, when allowed to burn, regenerate the forest, revitalize the watershed, and renew the soil. Fire sorts of resets the clock of an ecosystem. So fire is natural and beneficial, or I should say, over eons of time it has been. But with more people living in fire-prone areas, the benefits of fire are overshadowed by the destruction of homes and communities, and the grief of human deaths.
Birds can escape fire, but there has to be a suitable habitat to escape to. Being November, birds are not breeding, so nests and young are not being destroyed, but there are some long-term Bald Eagle and Osprey nests that will not survive the conflagration.
We shall see, after this epic fire is out, what nature and humans have endured.
I can only add that I have the utmost admiration for and appreciation of the fire and emergency personnel who are working so hard and often endangering themselves to protect the rest of us. Thank you very much.
For a different take on birds and wildfire, read about Firehawks, birds in Australia that deliberately set fires.