Fire Smoke and Migration

A Blackburnian warbler with a long flight ahead stops in Iroquois County to recharge before continuing to Central or South America for the winter.

September 9, 2023 – The calendar, a shared understanding of humans, says that autumn does not officially begin in the Northern Hemisphere until the 23rd of this month on the day of the astronomical event known as the autumnal equinox. For Warblers, those dainty little songbirds, instinct is the main driving force, and we begin to see the movement of these birds south of their summer range in mid-August as their fall migration begins. Blackburnian and Black-and-white warblers are just a few recent sightings in Kankakee and Iroquois counties. Seasonal weather patterns are part of what stimulates the bird migration; the strong northerly winds and cooler nights influence when the birds move south, but this year there is another factor that is not yet fully understood, and that is the impact from the historic, widespread, and devastating wildfires burning to the north. The wildfires in Canada began in March and have burned millions of acres of Canada’s boreal forests across all provinces and territories. The smoke and flames are as dangerous to birds as to humans, and there is little doubt that many birds have had to abandon nesting attempts in and around the impacted areas. There is still a good chance that the birds escaping the fire and smoke attempted to nest again in other areas. Nesting habitats in these northern forests have been and continue to be destroyed by this extreme climate event, and that charred landscape in the coming spring may be a real challenge for birds arriving for the breeding season. Fire has always had a role in the life cycle of the forested ecosystem, actually helping renew the boreal landscape; experts acknowledge that today’s fires are more extreme than in the past and can change which plant species grow back after these scorched earth events. As the fall migration intensifies over the coming days, migrating warblers from points north will hopefully be seen in our area of Illinois as they head south toward their winter range in the Gulf states, the Caribbean, and Central and South America. Only time will tell how these extreme climate events of our warmer, drier, and changing planet will impact the warblers and all other plant and animal species, for that matter. Let us hope that our indecisiveness and resistance to implementing a more urgent plan to reduce greenhouse gas emissions has not manifested into those proverbial chickens that have come home to roost.

Searching through the leafy branches for insects a Tennessee warbler shows itself for just a moment before continuing its hunt.