The Mountain Fire in Ventura County, now at over 20,000 acres, is creeping closer and closer to the neighborhood where I spent some of my childhood. Although I feel deeply for the people who are losing their homes, I can’t help but think about the birds I used to see in those hills behind the house, and the impact the fire has on them too. Outside of the direct loss of habitat, a couple recent studies shed some light on other impacts.

In 2020, the fire season in the western United States reached unprecedented levels. There were 116 fires active in September consuming nearly 5,145,230 acres with 80% of this footprint (4,093,795 acres from 68 fires) occurring within California, Oregon, and Washington.

Beginning in 2018, the USGS and partners marked Tule Greater White-fronted Geese (Anser albifrons elgasi; Tule goose) with collar-mounted GPS-enabled cellular transmitters to study movements and behaviors. With less than 15,000 individuals, the Tule goose is a Species of Special Concern in California. During migration, the Tule goose exhibits near absolute (95%) fidelity to a primary stopover site at the Summer Lake Wildlife Area in central Oregon. Typical fall migration, as observed from five transmitter-marked individuals in 2019, starts as a nearly direct route from the Cook Inlet in Alaska to Summer Lake Oregon that takes just over 4 days. The first half of fall migration between Alaska and Washington consists of flights over, and occasional short rests upon, the Pacific Ocean.

During fall migration in 2020, Tule geese responded to dense smoke by either stopping migration or altering direction and/or altitude of flights, which resulted in increased total flight time and distance. Three birds migrating over the ocean stopped and rafted for 52–72 hours before the smoke cleared and then moved inland. Landward migration of Tule geese through smoke or directly over fires resulted in disorganized paths, increases in altitude (up to13,123 feet or 2.5 miles!) to fly above the smoke plume, and stops in non-traditional habitats occurring far from traditional migratory pathways (Fig. 1). Ultimately, all individuals arrived at Summer Lake after delays caused by smoke which more than doubled average migration duration and extended the average flightpath during migration by 470 miles (+27%). The extended duration and distance of migration could reduce the bird’s body condition causing a bird to be more susceptible to predation and disease.

Although the technology does not yet exist to place transmitters on passerines, a recent study has addressed the impacts of smoke on passerines using bird capture data from the San Francisco Bay Bird Observatory’s Coyote Creek Field Station (CCFS). Researchers evaluated how the increasingly poor air quality from fires impacted the capture rate (as an indicator of activity rate or movement rate) and body mass of up to 21 species of passerines and 1 woodpecker; In general, birds were captured less frequently at mist nets following recent exposure to smoke, and repeated exposure to smoke was linked to loss of body mass in individual birds (www.sfbbo.org/wingbeat/sfbbo-data-shows-how-wildfire-smoke-impacts-birds ).

The impacts to birds from climate change can be both maddening and freighting. The environment is changing and there will be winners and losers in the plant and animal world. We, society, have an opportunity to have a say in what the future looks like.

Thanks to all who voted for Proposition 4. Prop 4 is a $10-billion bond to respond to the wide-ranging impacts of climate change and will provide critical funding for safe drinking water, wildfire prevention, clean energy, and natural lands and wildlife protection to boost the state’s climate resilience.

-Cliff Feldheim