The Conservation Column
By Pepper Trail
Editor’s Note: Due to the particularly sensitive and complex issues raised by the USFWS Draft Barred Owl Manage-ment Strategy, the RVAS Board held a special meeting with Dr. Trail in January 2024 to discuss the public comment letter that follows. Although the Board was not in complete agreement about the proposed strategy, we voted unani-mously to approve this letter as a fair and well-considered position that adds several important suggestions to improve the Barred Owl Management Strategy if/when it is approved.
In November, the US Fish and Wildlife Service released a Draft Barred Owl Management Strategy that attempts to deal with an extraordinarily difficult problem: the decline of Northern Spotted Owls in the face of Barred Owl expansion. Due to their larger size and aggressiveness, much more varied diet, smaller territories, and greater fecundity, Barred Owls are capable of pushing out Spotted Owls in even the most pristine old-growth. The FWS Preferred Alternative proposes to halt and perhaps reverse the Spotted Owl’s decline by killing up to 400,000 Barred Owls over a 30-year period throughout the range of both Northern and California Spotted Owls. Links to the FWS Strategy and Environmental Impact Statement are given at the end of this column.
The Strategy was open for public comments through January 16. The following is a shortened version of the com-ments that Rogue Valley Audubon submitted to FWS in response.
The Preferred Alternative is based on two assumptions:
• That the killing of huge numbers of Barred Owls is justified based on their classification as a “non-native” spe-cies.
• That the killing of huge numbers of Barred Owls actually represents a solution to Spotted Owl declines in the Pacific Northwest.
Our comments challenge both of these assumptions.
Classification of Barred Owls as “Non-Native”
Barred Owl expansion into the Pacific Northwest from eastern North America was made possible by human-caused habitat changes, both those due to the activities of European settlers and to the effects of climate change. Barred Owls did not begin to expand westward until the early 20th century, and likely didn’t reach Oregon and California until the 1970s. These facts are sufficient for FWS to consider them as “non-native” and subject to lethal control.
However, unlike other species considered “non-native” by FWS, the Barred Owl is a native North American bird, protected by the Migratory Bird Treaty Act. As species always do, it expanded its range when changing environmental conditions made that possible. We are living in an age often dubbed the Anthropocene due to the pervasive impacts of human activity on the biosphere. It would be difficult to find any species whose range has changed in the past century that was NOT responding to human-caused environmental changes. Range shifts in response to these changes will be essential to species survival. Will we intervene every time one expanding species displaces another? When two species compete, how can we dictate which “deserves” to survive?
Despite all that, Barred Owl removal might be justified as the only remaining option to prevent Spotted Owl extinction if it could actually work. However, there is no reason to believe that the FWS plan would meet its objective.
Can the Preferred Alternative Succeed?
FWS lethal removal experiments from 2009-2019 showed that removing Barred Owls can halt the population de-clines of Spotted Owls in limited areas. However, a meaningful definition of “success” requires an end point. Once the removal experiments stopped, Barred Owls soon recolonized those areas, and Spotted Owl declines resumed. The FWS preferred alternative envisions killing hundreds of thousands of Barred Owls over a 30-year span across the entire range of Spotted Owls. Then what?
When the threat posed by Barred Owls was first recognized, many of us hoped that old-growth forests, to which Spotted Owls are so superbly adapted, would prove to be the species’ stronghold. Surely Barred Owls couldn’t out-compete Spotted Owls there? As the amount of old-growth forests increased thanks to the protections of the Northwest Forest Plan, Spotted Owl populations would also increase, and Barred Owls would settle into a variety of woodland and younger forest habitats. Coexistence would be possible.
Sadly, it has not worked out that way. Barred Owls have proven capable of pushing out Spotted Owls in even the most pristine old-growth – for example, Redwoods National Park. That is why this huge killing campaign is being proposed, as a desperate last resort. But to “succeed,” the killing will have to go on forever – akin to keeping Spotted Owls on life support, with no prospect of ever resuming unmanaged existence.
There is no reason to think that Barred Owls will stop entering the Pacific Northwest from the east. And the large established Barred Owl populations in the region’s towns and woodlands will not stop dispersing into forests. This is not an island situation, where it is possible to kill every individual of a non-native species, and return the ecosystem to its prior natural state. FWS will never kill every Barred Owl in the Pacific Northwest.
A More Realistic Alternative
As stated in the Management Strategy (p. 35), “Non-native barred owls currently occur in dense populations in most of the range of the northern spotted owls.” The size of established Barred Owl populations throughout the Pacific Northwest makes it clear that their permanent removal would be impossible almost everywhere.
However, there are still a few places within the range of Spotted Owls where Barred Owls are not yet well established. In these areas, a targeted program of Barred Owl removal has at least a chance of succeeding, allowing the persistence of Spotted Owls.
The FWS Environmental Impact Statement includes Alternative 6, “Management Focused on Best Conditions,” which prioritizes Barred Owl management in the southern portion of the Northern Spotted owl range, where Spotted Owl populations have not decreased to the degree they have in the north. We believe that this approach has at least some chance of maintaining viable Spotted Owl populations without killing enormous numbers of Barred Owls. Specifically, our comments advocate the following priority areas:
For Northern Spotted Owls:
• the California Coast Province, especially the Marin/Sonoma Management Zone, which is relatively Barred Owl free.
• the California Cascades Province. Though this area does not support large Spotted Owl populations, Barred Owl control here would be particularly important to prevent the expansion of that species south into the Sierra Nevadas.
and, for California Spotted Owls:
• the Sierra Nevada population
• the Coastal-Southern California population
By focusing on California Spotted Owls, a targeted Barred Owl removal strategy could save that subspecies from the fate of most Northern Spotted Owl populations – elimination by this expanding competitor.
Regardless of alternative, ecological forest management research must be included (a recommendation from the Oregon Audubon Council):
Regardless of whether Alternative 2 or 6, or some other approach is adopted, USFWS should support research to lay out longer-term forest management strategies that will enable reducing or eliminating lethal removal while under-standing habitat requirements that minimize Barred Owl impacts on Northern Spotted Owls. Potential research recommendations:
a. Examination of survivorship of Spotted Owls in different sized viable nesting habitat patches co-occurring with Barred Owls. Hypothesis: even when barred owls are present, spotted owls will have higher survival rates (both nesting and adult survivorship) in larger suitable forest patches than smaller ones. There is some evidence to suggest reduced impact on Spotted Owls from Barred Owls’ competition when barred owl densities are lower, and that quality spotted owl habitat may buffer spotted owl populations from the impacts of barred owls, at least in the short-term.
b. Further examination of habitat preference differences between the two species to help inform subsequent management and coexistence of the two species in the long-term. Previous research has suggested that barred owls tend to prefer lower elevation and less sloped habitat as compared to Spotted Owls although most evidence suggests considerable overlap in habitat use and selection between the two species.
Conclusion. Spotted Owl management presents the Fish and Wildlife Service with an agonizing Sophie’s Choice – there is no “good” solution. The extinction of Spotted Owls by a superior competitor may be evolution in action, but that does not make it less heartbreaking. The killing of hundreds of thousands of Barred Owls may artificially prop up Spotted Owl populations, but would need to continue forever. How can that be justified ecologically or ethically?
Given these unacceptable alternatives, the Fish and Wildlife Service needs to step back and adopt more modest, targeted strategy. It should abandon its proposal to kill enormous numbers of Barred Owls, a native North American bird, in pursuit of the illusion of restoring Spotted Owls across their range. Instead, it must focus on the limited but realistic goal of protecting those remnant Spotted Owl populations that are not yet overrun by Barred Owls.
FWS Barred Owl Removal Strategy: https://www.fws.gov/sites/default/files/documents/Final%20draft%20Barred%20Owl%20Management%20Strategy.pdf
FWS Environmental Impact Statement, with the range of alternatives: https://www.fws.gov/sites/default/files/documents/Final%20draft%20Barred%20Owl%20EIS.pdf