Wildfire Impacts on Birds

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.

Figure 1. Transmitter Tule Geese migrating from Alaska to Summer Lake Oregon and then the Central Valley during a year with no smoke from large fires and during a year with extensive smoke from many fires. From Overton et al 2021, Megafires and thick smoke portend big problems for migratory birds (esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.3552).

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

Ferruginous Hawks, Burrowing Owls, and the Value of Citizen Science

As a birder, many of us have no doubt used eBird and participated in events like the Christmas Bird Count.  Collectively, this data, called Citizen Science by biologists can provide very important information for scientists to document bird distribution and abundance.  A 2024 paper in the Journal of Raptor Research by Ed Pandolfino, Lilly Douglas, and Chris Raye on Ferruginous Hawks wintering in California (https://www.researchgate.net/publication/381305123_Population_Trends_of_the_Ferruginous_Hawk_Buteo_regalis_Wintering_in_California ) shows just how valuable this type of data can be.  

Using Christmas Bird Count data for a 25-yr period from 22 California Christmas Bird Count circles in the core winter range of Ferruginous Hawks, they found a significant positive trend. California’s wintering population of Ferruginous Hawks is increasing. This is surprising given the ongoing declines of this species’ preferred winter habitat in California during this same time period and with the continent-wide negative trends observed for most grassland bird species.

Figure 1. Year-round migration patterns of adult Ferruginous Hawks breeding in the Pacific Northwest, USA, and tracked for up to 6 yr (n ¼ 30). Solid lines are tracks from birds outfitted with GPS transmitters; dotted lines are tracks from birds outfitted with ARGOS platform transmitter terminals (https://www.argos-system.org/products/transmitters/). Reprinted with permission from Watson et al. (2018) (from Pandolfino et al 2024).

It is not entirely clear why California’s wintering Ferruginous Hawk populations are increasing.  It’s thought that most of our wintering Ferruginous Hawks come from Washington and Oregon (Figure 1) however other regions of the West are poorly studied. Some possible explanations include: California’s wintering habitats may have an abundance of food for the species, the loss of wintering habitats in California may concentrate the hawks in areas where they are more likely to be observed, or wintering habitats outside of California could be decreasing causing more hawks to come to California.  Whatever the case the fact that wintering population are increasing despite generally decreasing breeding populations and loss of habitats will no doubt prompt more research and highlights how important Citizen Science data can be for conservation. Though not used here, eBird data can be just as valuable.

Speaking of raptors, California’s conservation community got a victory on October 10th when the California Fish and Game Commission voted unanimously to support a petition by The Center for Biological Diversity, Defenders of Wildlife, Burrowing Owl Preservation Society, Santa Clara Valley Audubon Society, Urban Bird Foundation, Central Valley Bird Club, and San Bernardino Valley Audubon Society to list western Burrowing Owl as threatened or endangered pursuant to the California Endangered Species Act (https://fgc.ca.gov/CESA#wbo).  Chris Conard, who sits on the Central Valley Bird Club Conservation Committee as well as Sacramento Audubon’s Conservation Committee played a large role in providing the biological information for the petition and testified in person at the meeting. In fact, this petition brought together the Central Valley Bird Club and Sacramento Audubon and presented the opportunity for the Central Valley Bird Club’s Conservation Committee and Sacramento Audubon’s Conservation Committee to collaborate. It has helped lay the ground work for us to work more closely on conservation issues moving forward as three of the Sacramento Audubon Conservation Committee members also sit on the CVBC Conservation Committee (myself, Chris Conard, and Dan Airola).

I hope you are all enjoying the change of season and the arrival of our wintering birds!

September Migration

September is one of my favorite months in the Central Valley. We start to see some cooler weather and a taste of fall. For birders, it also marks a time when some of our early migrants start to show up. The Northern Pintail has already begun arriving along with Northern Shovelers and Green-winged Teal, and I am looking forward to winter. The habitat conditions waiting for our migrant and wintering waterbirds look to be good. Water conditions are better than a drought but not as good as a wet year. Rice, a key habitat for our water birds, is abundant throughout the Sacramento Valley.

One of the things that amazes me about some bird species is their migration distances.  Many of our wintering birds travel a long way to get to California’s Central Valley, however, few species travel further than our Arctic nesting geese (Figure 1.). 

Figure 1. Migration paths of 3 species and one subspecies of geese as tracked by GPS transmitters from work by the USGS and UC Davis.

Arctic nesting geese aren’t the only birds to make long migratory flights. Shannon Skalos recently completed a study on Northern Harriers in the Suisun Marsh. She found that while some wintering Northern Harriers breed in the Suisun Marsh, others migrate north to nest in Alaska and portions of the Arctic (Figure 2.).

Figure 2. The migration path of a Northern Harrier with a GPS transmitter attached from work conducted by Shannon Skalos while at UCD in collaboration with the USGS.

Another long distance migrant is the Golden-crowned sparrow. A 2024 study of Golden-crowned sparrows documented a similar migration path and distance from Alaska and British Columbia to California (Figure 3. https://doi.org/10.1371/journal.pone.0305369 ).

Figure 3. Breeding locations of Golden Crowned Sparrows that were captured at UC Davis (purple), UC Santa Cruz (yellow), or at Point Reyes National Seashore (green).

Waterfowl are large enough for transmitters that provide high quality data over long periods. One of the things that allows for is an estimate of flight speed during migration. A 2019 study found migration flight speeds for 6 species of waterfowl average 33-51 mph with peak speeds of 50-85 mph (Table 1)!

The migration of these species is amazing and can be awe-inspiring, and we still have much to learn. The next time you are out this Fall or Winter and see a bird, take a moment to recognize that the bird may have traveled 100’s or 1000’s of miles to get to California!

From a birding standpoint, one of the benefits of climate change is that many species of birds are shifting or changing their migration patterns. You never know what is going to show up! Who remembers the Garganey that showed up at Bridgeway Island in West Sacramento in winter of 2019-2020, or the Black Skimmer that showed up at the Yolo Wildlife Area in 2017? What could show up this year…a Red-faced Cormorant or maybe the Narcissus Flycatcher? Let’s get out and bird!

On another note, this month I will be at the McKinley Library September 27 from 3:30 - 4:30 presenting to 5-10 year olds. Come and take an up-close look at bones and skulls, tracks and scat, nests and eggs, wings and feathers, and learn about mammals and birds and the clues they leave us.   https://engage.saclibrary.org/event/11573317

-Cliff Feldheim

The Conservation Column

 As Conservation Chair, I want to kick off a column highlighting some of our conservation efforts. In December 2023, I took on the role of Conservation Chair and developed a Conservation Committee. Collectively, the members of the Conservation Committee have decades of experience working on environmental regulations and with state, federal, and local governments, as well as with actively conserving birds and their habitats.

At times there seems as though there is a never ending stream of active projects that could have negative impacts on birds (e.g., continued development in Natomas, Army Corps proposal to clear vegetation along the American River, and DWR’s Delta Conveyance “Tunnel” Project). It can be very difficult to change the course of a project once an environmental document is made public. However, one of the best ways to influence change is through a coalition. To that end, I represent Sacramento Audubon on the board of the Environmental Council of Sacramento (ECOS). In addition to ECOS staff, 17 nonprofit community-based organizations sit on the board. Over its’ 50 year history, ECOS has demonstrated great success in bringing partners together to achieve positive change to environmental documents, even if the only way was with a lawsuit. While that approach tends to be reactive, one of our goals is to work with our partners to engage land managers and decision makers when projects are in the development stage and work with them in a proactive manner to reduce potential impacts. 

Mountain Plover, Image by Daniel Lee Brown

Along those lines, Sacramento Audubon has been asked to be on a Working Group to conserve Mountain Plovers. The Working Group is envisioned to have members from all the states in which the species breeds and winters and will be led by the Rocky Mountain Bird Conservancy at the direction of the US Fish and Wildlife Service. As part of that effort, we will be writing a paper on the status of the species in the Central Valley, developing a winter survey protocol, and lead the implementation of the survey which will begin this winter.  

Finally, education is a part of conservation. In July, I had the opportunity to spend the morning with 45 K-6 campers at Camp Adobe, engaging the kids with hands on activities and seeing their awe and wonder as they examined the colors of the speculum on a Mallard wing or gasped in amazement at the size of a hummingbird egg!

Cliff with campers at Camp Adobe