AUTHOR BLOG: How vulnerable are California’s Great Gray Owls to wildfire?

Rodney Siegel

Linked paper: Short-term resilience of Great Gray Owls to a megafire in California, USA by R.B. Siegel, S.A. Eyes, M.W. Tingley, J.X. Wu, S.L. Stock, J.R. Medley, R.S. Kalinowski, A. Casas, M. Lima-Baumbach, and A.C. Rich, The Condor: Ornithological Applications 121:1, February 2019.

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A Great Gray Owl nest within an area recently burned by the 2013 Rim Fire in Yosemite National Park. Photo credit: Dustin Garrison

Throughout western North America, the combination of longer, hotter dry seasons and dense forests is yielding more frequent, larger, and more severe wildfires, including immense “megafires.” Habitat loss from increased fire activity could put wildlife species that depend on mature forest at risk. Concern over this threat is an increasingly important driver of forest management efforts in California’s Sierra Nevada, but recent efforts to assess the consequences of megafires on one bird species associated with the region’s mature forest, the California Spotted Owl (Strix occidentalis), have yielded conflicting results. Some research suggests that California Spotted Owls may be vulnerable to habitat loss and local extirpation due to forest fire, while other studies indicate that the owls may be fairly resilient, at least to low- and mixed-severity fire.

Like Spotted Owls, the Great Gray Owl (Strix nebulosa) is imperiled in California (where it is listed by the state as endangered) and is associated with mature forest. California’s Great Gray Owls typically nest in large, dead trees in shady forests adjacent to mountain meadows. In 2013 the Rim Fire, the largest fire on record in the Sierra Nevada, burned 104,000 hectares in Yosemite National Park and Stanislaus National Forest – the heart of Great Gray Owl’s range in California. Within the burned area were 23 meadows known to be occupied by Great Gray Owls during the decade prior to the fire, nearly a quarter of all known or suspected territories in California at the time.

We analyzed 13 years (2004–2016) of Great Gray Owl survey data from 144 meadows in the central Sierra Nevada, including meadows inside and outside the Rim Fire perimeter in Yosemite National Park and Stanislaus National Forest, to assess the effect of the fire on Great Gray Owls’ persistence during the early post-fire years. Would Great Gray Owls continue to use historically occupied meadows within the burned area, or would the fire cause those sites to go vacant?

During three years of surveys after the fire, we detected Great Gray Owls at nearly all (21 of 22) surveyed meadows within the burned area that were occupied during the decade prior to the fire, and anecdotal evidence indicated that the owls were not only present but actually nested at many of these sites during the post-fire years. Analyzing the full dataset, including surveys conducted before and after the fire as well as inside and outside the burned area, revealed that rather than decreasing after the fire, owls’ persistence actually increased at meadows across the study area. This increase suggests that the owls remained resilient during the three years after the Rim Fire and that other factors such as weather were likely favorable to Great Gray Owls during those post-fire years.

Our results indicate that wildfires, including unusually large megafires, may not pose a great threat to Great Gray Owls in the short term. However, processes not apparent during our study’s short timeframe, including the eventual decay and loss of the large snags that the fire created, could affect the owls’ longer-term persistence after fire. Further study is needed to determine whether Great Gray Owls continue to be resilient to fire over longer timeframes.

More information about The Institute for Bird Populations’ Great Gray Owl research and conservation efforts is available at

Road Proximity May Boost Songbird Nest Success in Tropics

white-rumped shama
A juvenile White-rumped Shama with identifying leg bands. Photo credit: Rongrong Angkaew

In the world’s temperate regions, proximity to roads usually reduces the reproductive success of birds, thanks to predators that gravitate toward habitat edges. However, the factors affecting bird nest success are much less studied in the tropics—so does this pattern hold true? New research published in The Condor: Ornithological Applications shows that interactions between roads, nesting birds, and their predators may unfold differently in Southeast Asia.

Rongrong Angkaew of King Mongkut’s University of Technology Thonburi and her colleagues placed 100 next boxes for the cavity-nesting White-rumped Shama in forest interior and 100 near a road at an environmental research station in northeast Thailand. Monitoring nests and radio-tracking 25 fledglings from each site for seven weeks, they found that nest success was 12% higher and post-fledging survival 24% higher at the edge versus the interior—the opposite of the pattern commonly observed in temperate regions.

“There were some special challenges involved in carrying out the field work,” says Angkaew. “When we started setting up the nest boxes in the field, we found a lot of tracks and other signs of poachers and illegal hunting, so we had to avoid some parts of the forest edge in order to reduce human disturbance to our nest boxes, which could have affected nestling and fledgling survival rates.”

Predators caused 94% of nest failures and 100% of fledgling mortality, and locally important predators of small birds, such as green cat snakes, northern pig-tailed macaques, and raptors, appear to prefer interior forest habitat. Fledglings also preferred to spend time in dense understory habitat, which provides cover from predators and was more available near roads.

Overall, the study’s results suggest that the effects of roads on birds’ reproductive success depend on local predator ecology—the same rules don’t necessarily apply in different biomes. Angkaew and her coauthors hope that more studies like theirs will help identify key nest predators and assess their foraging behaviors in multiple landscapes, in order to determine the best ways to conserve vulnerable bird species in areas affected by human development.

Nesting near road edges improves nest success and post-fledging survival of White-rumped Shamas (Copsychus malabaricus) in northeastern Thailand is available at

About the journal: The Condor: Ornithological Applications is a peer-reviewed, international journal of ornithology, published by the American Ornithological Society. For the past two years, The Condor has had the number one impact factor among 27 ornithology journals.

Possible Oahu Populations Offer New Hope for Hawaiian Seabirds

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A juvenile Newell’s Shearwater. Photo credit: Lindsay Young.

The two seabird species unique to Hawaii, Newell’s Shearwaters and Hawaiian Petrels, are the focus of major conservation efforts—at risk from habitat degradation, invasive predators, and other threats, their populations plummeted 94% and 78% respectively between 1993 and 2013. However, a new study in The Condor: Ornithological Applications offers hope of previously undetected colonies of these birds on the island of Oahu, from which they were believed to have vanished by the late 1700s.

Shearwaters and petrels nest colonially in crevices, burrows, and under vegetation at mid to high elevations. They currently breed on other Hawaiian islands including Kauai and Maui, but were both believed to have extirpated from Oahu prior to European contact in 1778; biologists believed that occasional records from the island were birds thrown off-course at night by city lights.

Pacific Rim Conservation’s Lindsay Young and her colleagues used a spatial model based on elevation, forest cover, and illumination to identify potential suitable breeding habitat for both species on Oahu, then deployed automated acoustic recording units at 16 sites on the island to listen for the birds’ calls in 2016 and 2017, accessing remote mountain locations via helicopter. To their surprise, they detected petrels at one site and shearwaters at two sites.

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Automated acoustic recording units picked up the calls of endangered seabirds at remote locations on Oahu. Photo credit: Lindsay Young

“We were doing a statewide survey for these species for the U.S. Fish and Wildlife Service as part of recovery action planning, but Oahu was not initially included as one of the sites to survey, since evidence suggested they weren’t there,” says Young. “Since we’re Oahu-based, we thought we would at least put a few recording units out to see if there was anything. And we were surprised, to say the least, that we not only had calls detected, but detected both species across two years.”

These could be the last survivors of remnant breeding populations on Oahu, or they could be young birds from other islands that are searching for mates and breeding sites. “Either way, it gives us hope that we will be able to use social attraction—that is, using calls and decoys—to attract them nest on an island where they were once abundant,” says Young. Oahu birds could help boost connectivity between individual island populations and provide extra insurance in case any one island’s seabird population is decimated by an event such as a hurricane. As petrel and shearwater numbers continue to decline, protecting Hawaii’s remaining seabirds remains a major conservation priority in the region, and the possibility that they’re continuing to breed on Oahu provides new reason for optimism.

Evidence of Newell’s Shearwaters and Hawaiian Petrels on Oahu, Hawaii is available at

About the journal: The Condor: Ornithological Applications is a peer-reviewed, international journal of ornithology, published by the American Ornithological Society. For the past two years, The Condor has had the number one impact factor among 27 ornithology journals.

Thank You to Kathleen Erickson, Outgoing AOS Journals Director

CaptureToday the American Ornithological Society is saying a fond farewell to Kathleen Erickson, who has led AOS’s publications since 2013.

Kathleen was hired in 2013 as the Managing Editor of The Auk and The Condor, working for the newly created Central Ornithological Publications Office, a joint venture of the American Ornithologists’ Union and the Cooper Ornithological Society that preceded the societies’ eventual merger in 2016. Kathleen was promoted to Journals Director after the merger.

Under Kathleen’s leadership, the publications team created a successful publicity program, increased open access to Auk and Condor papers, reduced author page fees, and kept in contact with more than 8,000 ornithologists through the journals’ email newsletter and monthly content alerts.

“Getting the joint publications office up and running was like creating a startup, and it has been the dream job of my thirty-year publishing career,” says Kathleen. “The ornithology community is a passionate and down-to-earth group of professionals, whom I will miss. You’ll find me out at Point Blue counting birds!”

Catherine Lindell Named Editor of The Condor: Ornithological Applications

Catherine LindellThe American Ornithological Society announces the appointment of Catherine Lindell as the 15th Editor-in-Chief of The Condor: Ornithological Applications, one of two peer-reviewed journals published by AOS. Dr. Lindell is an Associate Professor of Integrative Biology at Michigan State University and an AOS Fellow. She will begin her position in 2019.

The AOS Council selected Dr. Lindell to lead the journal based on her comprehensive vision for The Condor’s future, including plans to increase interdisciplinary and international submissions to the journal and involve students in the manuscript review process, as well as her commitment to diversity and inclusiveness in scientific publishing. Dr. Lindell has conducted research with a wide network of colleagues in Latin America, a region that is currently underrepresented in AOS journals. Her research interests include the ecosystem services (and disservices) of birds in managed landscapes such as orchards.

Dr. Lindell will succeed current Editor-in-Chief Phil Stouffer, who will be stepping down after six years in the role. “I’m really pleased to have the opportunity to continue the great work of Phil Stouffer and the AOS Council,” says Dr. Lindell. “We will keep building The Condor into the go-to outlet for research from around the world on the roles birds play in and across ecosystems and their conservation and management.”

“I’m excited that Catherine Lindell will be the next Editor-in-Chief of The Condor,” says Dr. Stouffer. “Serving as editor of the journal has been a rewarding challenge for me, and I’ve been lucky to be part of a great team that takes pride in putting out the best possible product. Dr. Lindell has the experience and vision to take the journal to the next level. I’m sure she’ll do a great job.”

“We hope that Dr. Lindell’s appointment will be the beginning of an exciting new era for The Condor,” adds Kathy Martin, president of AOS. “She is especially well-positioned to increase the profile of Latin American ornithology in the journal, and AOS is confident in her ability to continue this venerable publication’s journey into the twenty-first century.”

The Condor: Ornithological Applications was first published as the Bulletin of the Cooper Ornithological Club in 1899. It became The Condor the following year, and was officially renamed The Condor: Ornithological Applications in 2014, with a new focus on applied ornithological topics such as conservation and management. In 2016, the Cooper Ornithological Society merged with the American Ornithologists’ Union to form the American Ornithological Society, which now publishes both The Condor and its sister journal The Auk. As of 2017, The Condor has the highest impact factor of any ornithology journal. Dr. Lindell will be the first woman to lead The Condor in its 120-year history.


About the American Ornithological Society

The American Ornithological Society (AOS) is the largest and most influential ornithological society in the world. The society provides leadership in ornithological research and a rigorous scientific basis for the conservation of birds and invests more in research awards and direct support of students and early professionals than any other society devoted to ornithology. AOS publishes two international journals, The Auk: Ornithological Advances and The Condor: Ornithological Applications, which have consistently had among the highest impact factors of the world’s ornithological journals, and the book series Studies in Avian Biology. The society’s checklists serve as the accepted authority for scientific and English names of birds in North, Middle, and South America. AOS is also a partner in the online publication of The Birds of North America with the Cornell Laboratory of Ornithology. For more information, see