Historical Forest Conditions within the Range of the Pacific Fisher and Spotted Owl in the Central and Southern Sierra Nevada, California, USA

2016 ◽  
Vol 36 (1) ◽  
pp. 8-19 ◽  
Author(s):  
Chad T. Hanson ◽  
Dennis C. Odion
Keyword(s):  
Sierra Nevada ◽  
Spotted Owl ◽  
The Pacific ◽  
Historical Forest ◽  
Forest Conditions

Nature and the Reproduction of Endangered Space: The Spotted Owl in the Pacific Northwest and Southern California

1996 ◽  
Vol 14 (6) ◽  
pp. 683-708 ◽  
Author(s):  
James D Proctor ◽  
Stephanie Pincetl
Keyword(s):  
United States ◽  
Pacific Northwest ◽  
Sierra Nevada ◽  
Southern California ◽  
The United States ◽  
Private Lands ◽  
Spotted Owl ◽  
The Pacific ◽  
California Spotted Owl ◽  
Set Up

Recent efforts to protect biodiversity in the United States often reproduce the literal and figurative divisions of space that have originally endangered target species. Nature as redefined by these efforts is as much a social construction as it is some biophysical entity under siege by humans, We focus on the categorical and spatial distinctions between landscapes prioritized for protection and landscapes given less priority or ignored altogether. These distinctions, we wish to demonstrate, reflect pragmatic considerations of habitat quality and political expediency, but they also are enmeshed in dualist nature–culture ideologies that serve to legitimate and ultimately to reproduce the different practices that occur on these landscapes. We focus on protection of spotted owl habitat, one of the most important cases of biodiversity conservation in the United States since the passage of the Endangered Species Act. We consider recent spotted owl protection efforts in the Pacific Northwest and southern California. In the Pacific Northwest, spotted owl protection plans on public forests have been cited as justification for casing habitat protection on private lands, in spite of the major historical biodiversity role of these forestlands. In California, spotted owl policy deliberations for the urbanized forests of southern California have lagged far behind those in the Sierra Nevada, even though owl populations have declined faster in southern California than anywhere else in the state. These cases are indicative of a nature epistemologically understood and ontologically constructed as separate from culture, of what Latour would call an act of purification set up against the undeniably hybrid character of nature–cultures in late modernity. It is precisely this recognition of nature–culture intertwining, however, that will prove central to the creation of sustaining habitats for nonhuman life.

scholarly journals Habitat Selection in a Changing Environment: The Relationship Between Habitat Alteration and Spotted Owl Territory Occupancy and Breeding Dispersal

The Condor ◽  
2007 ◽  
Vol 109 (3) ◽  
pp. 566-576 ◽  
Author(s):  
Mark E. Seamans ◽  
R.J. Gutiérrez
Keyword(s):  
Habitat Selection ◽  
Sierra Nevada ◽  
Coniferous Forest ◽  
Canopy Cover ◽  
Habitat Alteration ◽  
Breeding Dispersal ◽  
Conifer Forest ◽  
Avian Behavior ◽  
Spotted Owl ◽  
The Relationship

Abstract Abstract. Understanding the effect of habitat alteration on avian behavior is important for understanding a species' ecology and ensuring its conservation. Therefore, we examined the relationship between Spotted Owl habitat selection and variation in habitat in the Sierra Nevada. We estimated habitat selection by modeling the probability of territory colonization (γ), territory extinction (ε), and breeding dispersal in relation to the amount of mature conifer forest within and among territories. Alteration of ≥20 ha of mature conifer forest (coniferous forest with >70% canopy cover dominated by medium [30.4–60.9 cm dbh] and large [>60.9 cm dbh] trees) within individual territories (n  =  66) was negatively related to territory colonization and positively related to breeding dispersal probability. Although territory extinction was negatively related to the amount of mature conifer forest, it was not clear whether this relationship was due to variation of mature conifer forest within or among territories. Although modeling results for territory colonization and extinction generally supported the hypothesis that individuals are “ideal” when selecting a habitat in the sense that they settle in the highest-quality site available, we did not find a clear benefit in terms of habitat quality for Spotted Owls that exhibited breeding dispersal.

scholarly journals Are Barred Owls Displacing Spotted Owls?

The Condor ◽  
2003 ◽  
Vol 105 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Elizabeth G. Kelly ◽  
Eric D. Forsman ◽  
Robert G. Anthony
Keyword(s):  
Pacific Northwest ◽  
Current Status ◽  
Spotted Owl ◽  
Strix Occidentalis ◽  
Strix Varia ◽  
The Pacific ◽  
Spotted Owls ◽  
Before And After ◽  
Strix Occidentalis Caurina ◽  
Barred Owls

Abstract Barred Owls (Strix varia) have expanded their range into the Pacific Northwest, and anecdotal evidence suggests that they may be displacing the federally threatened Northern Spotted Owl (Strix occidentalis caurina). Our objectives were to describe the current status of Barred Owls in Oregon and compare occupancy of Spotted Owls in historic Spotted Owl territories before and after Barred Owls were first detected in those territories. Between 1974 and 1998, we estimated that 706 different Barred Owl territories were located in Oregon. From 1989–1998 an average of 60 new Barred Owl territories were located in Oregon each year. In Spotted Owl demographic study areas in Oregon and Washington, Barred Owl detections increased at Spotted Owl territories from 1987–1999. Occupancy of Spotted Owl territories declined after Barred Owls were detected within 0.80 km of the territory center. When Barred Owls were detected 0.81–2.40 km from Spotted Owl territory centers, occupancy of Spotted Owls was only marginally less than at territories without Barred Owls. This suggests that the frequency and intensity of interactions between the two species is negatively associated with distance between them. Our results suggest that land managers and regulatory agencies should regard Barred Owls as a threat to Spotted Owls, particularly if Barred Owls continue to increase in number as they have during the past 25 years. ¿Está Strix varia Desplazando a Strix occidentalis caurina? Resumen. Desde su expansión hacia el Pacífico Noroeste, existe evidencia anecdótica de que Strix varia podría estar desplazando a S. occidentalis caurina. Nuestros objetivos fueron describir el estatus actual de S. varia en Oregon y comparar la ocurrencia de S. occidentalis caurina en sus territorios históricos antes y después de que S. varia se detectó por primera vez en dichos territorios. Entre 1974 y 1998, estimamos que se confirmaron 706 territorios diferentes de S. varia en Oregon. Entre 1989 y 1998, se localizaron en promedio 60 nuevos territorios de S. varia anualmente. En áreas con estudios demográficos de S. occidentalis caurina en Oregon y Washington, las detecciones de S. varia en territorios de S. occidentalis caurina se incrementaron entre 1987 y 1999. En comparación con territorios sin S. varia, la ocupación de territorios de S. occidentalis caurina disminuyó luego de que se detectaron individuos de S. varia a menos de 0.80 km del centro del territorio. Cuando se detectaron individuos de S. varia entre 0.81 y 2.40 km del centro de los territorios, la ocupación de éstos fue sólo marginalmente menor que en territorios sin S. varia. Esto sugiere que la frecuencia e intensidad de la interacción entre las dos especies está asociada con la distancia entre ellas. Nuestros resultados sugieren que las autoridades ambientales y de regulación deben considerar a S. varia como una amenaza para S. occidentalis caurina, particularmente si los números de S. varia se siguen incrementando como en los últimos 25 años.

scholarly journals Restoring historical forest conditions in a diverse inland Pacific Northwest landscape

Ecosphere ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. e02400 ◽  
Author(s):  
James D. Johnston ◽  
Christopher J. Dunn ◽  
Michael J. Vernon ◽  
John D. Bailey ◽  
Brett A. Morrissette ◽  
...  
Keyword(s):  
Pacific Northwest ◽  
Historical Forest ◽  
Forest Conditions

Revision of the milliped genus Xystocheir Cook (Polydesmida: Xystodesmidae)

1996 ◽  
Vol 74 (7) ◽  
pp. 1336-1363 ◽  
Author(s):  
Rowland M. Shelley
Keyword(s):  
San Francisco ◽  
Sierra Nevada ◽  
Pacific Coast ◽  
Local Population ◽  
Species Group ◽  
Western Slope ◽  
Species Status ◽  
The Pacific ◽  
Mendocino County ◽  
Species Groups

The California milliped genus Xystocheir Cook, occurring along the Pacific Coast and the western slope of the Sierra Nevada, comprises nine species, three being divided into a total of seven subspecies; the species are combined into four species-groups named for the oldest component. Xystocheir dissecta (Wood), abundant around San Francisco – San Pablo and Monterey bays, comprises intergrades, one true subspecies, and two apparent semispecies that are treated as subspecies; additionally, a local population in southern Mendocino County has achieved reproductive isolation and attained species status. Two new combinations, X. reducta (Causey) and X. modestior (Chamberlin), are proposed, along with the following new synonymies: Paimokia Chamberlin under Xystocheir, X. acuta Cook, X. francisca and X. milpitas, both by Chamberlin, and Cheirauxus sapiens Chamberlin under X. d. dissecta, new status; and Delocheir conservata and D. dalea, both by Chamberlin, under X. dissecta taibona Chamberlin, new status. The following new species-group taxa are diagnosed: the subspecies Xystocheir dissecta microrama, Xystocheir modestior haerens, and Xystocheir stolonifera uncinata, and the species X. prolixorama, X. solenofurcata, X. brachymacris, X. stenomacris, X. bistipita, and X. stolonifera.

scholarly journals Is “Fuel Reduction” Justified as Fire Management in Spotted Owl Habitat?

Birds ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 395-403
Author(s):  
Chad T. Hanson
Keyword(s):  
Forest Management ◽  
Sierra Nevada ◽  
Tree Mortality ◽  
Habitat Degradation ◽  
Fire Suppression ◽  
Fire Severity ◽  
Indirect Evidence ◽  
Fuel Reduction ◽  
Spotted Owl ◽  
California Spotted Owl

The California spotted owl is an imperiled species that selects mature conifer forests for nesting and roosting while actively foraging in the “snag forest habitat” created when fire or drought kills most of the trees in patches. Federal agencies believe there are excess surface fuels in both of these habitat conditions in many of California’s forests due to fuel accumulation from decades of fire suppression and recent drought-related tree mortality. Accordingly, agencies such as the U.S. Forest Service are implementing widespread logging in spotted owl territories. While they acknowledge habitat degradation from such logging, and risks to the conservation of declining spotted owl populations, agencies hypothesize that such active forest management equates to effective fuel reduction that is needed to curb fire severity for the overall benefit of this at-risk species. In an initial investigation, I analyzed this issue in a large 2020 fire, the Creek Fire (153,738 ha), in the southern Sierra Nevada mountains of California. I found that pre-fire snag density was not correlated with burn severity. I also found that more intensive forest management was correlated to higher fire severity. My results suggest the fuel reduction approach is not justified and provide indirect evidence that such management represents a threat to spotted owls.

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