Recovery Plan for the Northern Spotted Owl - DRAFT
Recovery Plan for the Northern Spotted Owl - DRAFT Recovery Plan for the Northern Spotted Owl - DRAFT
Ca n a d aEastern Washington Cascades-- - - - |Olympic Peninsula -…--…Western Washington Lowlands --Western Washington Cascades… --t-WashingtonOregon Coast Range… - - - -The Willamette Valley… - - - - -(has virtually no northern spotted owlhabitat; is not discussed as a province inthis recovery plan) OregonEastern Oregon Cascades -- - -- O--regWestern Oregon Cascades es-- -Oregon Klamath ----- --California Cascades -…-…-…-…- - -California Klamath…-…---California Coast- …--rCaliforniaFigure 2.2. Provinces within the range of the northern spotted owl in the United States.32
2. Population StatusThere are no estimates of the historical population size of the northern spottedowl, but owls are believed to have inhabited most old-growth forests throughoutthe Pacific Northwest and northwestern California, and they still are foundwithin their historical range in most areas where suitable habitat remains(Thomas et al. 1990).Northern Washington and southern British Columbia represent the northernextent of the range of the owl. Population densities and numbers are lowest inthese areas, with fewer than 20 pairs located in extensive surveys along theU.S. border with British Columbia (Dunbar 1990). A small, potentially isolatedpopulation of about 125 known pairs of spotted owls is located on the OlympicPeninsula in and around Olympic National Park (Fredrickson et al. 1989,Washington Department of Wildlife (WDW) 1991). Fewer than 50 owls havebeen located in recent extensive surveys in the Coast Ranges of southwesternWashington and northwestern Oregon north of Corvallis (Forsman 1986,Forsman et al. 1987, Irwin et al. 1989b, Oregon Department of Fish andWildlife (ODFW) 1991). Populations also decrease in size and density from theMendocino National Forest south to Point Reyes, California, and from theKlamath province east to the area of contact with the California subspecies inthe Sierra Nevada Range (Gould pers. comm.).Most of the present population of owls is found in the Cascades and Klamathprovinces in Oregon, and in the Klamath and Coast Range provinces in northwesternCalifornia (Advanced Sciences Inc. 1989, Beak Consultants 1989,Brown 1989, Diller 1989, Irwin et al. 1989c, Kerns 1989a and 1989b, Pious1989, ODFW 1991, WDW 1991). Distribution of remaining habitat is similar tothe present distribution of spotted owls.More than 86 percent of currently known pairs of owls has been observed onfederally managed lands. The distribution of these pairs varies widely by landownership, state, and physiographic province (Table 2.3). Although inventoriesare least complete in California, about 30 percent of the habitat and populationof spotted owls may occur in the Coast Range (Gould pers. comm.).Only population data gathered during a 5-year period were analyzed during thedevelopment of the recovery plan because they may provide more reliableestimates of actual numbers than longer cumulative periods or single-yearcounts, given the rapidly changing quantity and quality of habitat. It is alsothe period with the most intense inventories, and is within the average lifespan of the species (about 8 years). Depending on availability of data, theperiod used was either 1986 through 1990 or 1987 through 1991 (see Table2.3).Inventories from 1987 through 1991 indicate a total of about 3,500 knownpairs of northern spotted owls in Washington, Oregon, and northern California(Table 2.3). This number is a minimum estimate of the true population size.The actual number of spotted owls remaining is unknown.3. Significant Threats to the Northern Spotted OwlTable 2.4 provides a summary of significant threats to northern spotted owlpopulations by physiographic province. Threats were characterized as follows:Severe: The problem poses a severe threat to the population at thecurrent time or will pose such a threat within the next several generations.The likely consequence is failure to maintain a population distrib-33
- Page 1 and 2: I 1.2:Sp 6/draftRecovery Plan for t
- Page 7: List of FiguresTable 4.1 Abbreviate
- Page 11 and 12: Recovery ObjectiveSecretary of the
- Page 13 and 14: Management Rules for Designated Con
- Page 15 and 16: Monitoring and Research ProgramThe
- Page 17: Chapter IIntroduction1
- Page 20 and 21: "Threatened species" means a specie
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- Page 24 and 25: lished works and many government do
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- Page 29 and 30: I- \IzXelT - - -.11 I..., ... I.."
- Page 32 and 33: spring. Territories probably are sm
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- Page 36 and 37: also use a variety of nest sites in
- Page 38 and 39: Home Range SizeHome range is define
- Page 40 and 41: Table 2.2. Median amounts of old-gr
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- Page 44 and 45: Dispersal1984, Thomas et al. 1990,
- Page 46 and 47: 4. ConclusionOur knowledge of the n
- Page 50 and 51: Table 2.3. Estimated spotted owl ha
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- Page 54 and 55: Table 2.5. Results of surveys for s
- Page 56 and 57: isolated. In these provinces, small
- Page 58 and 59: centers for 30 to 35 spotted owl te
- Page 60 and 61: Southwest Washington occupies a key
- Page 62 and 63: Distribution of Habitat and Populat
- Page 64 and 65: Province Isolation. The eastern Was
- Page 66 and 67: were in suitable habitat condition.
- Page 68 and 69: Estimated acres of forest landbase:
- Page 70 and 71: owned and contain little suitable h
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- Page 76 and 77: miles from the contiguous populatio
- Page 78 and 79: In comparison, the southern part of
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- Page 86 and 87: transfer of one area to the Grand R
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- Page 92 and 93: The results of a consultation are s
- Page 94 and 95: - Since landowners already face cut
- Page 96 and 97: 4. Cumulative Effects AssessmentThe
Ca n a d aEastern Washington Cascades-- - - - |Olympic Peninsula -…--…Western Washington Lowlands --Western Washington Cascades… --t-WashingtonOregon Coast Range… - - - -The Willamette Valley… - - - - -(has virtually no nor<strong>the</strong>rn spotted owlhabitat; is not discussed as a province inthis recovery plan) OregonEastern Oregon Cascades -- - -- O--regWestern Oregon Cascades es-- -Oregon Klamath ----- --Cali<strong>for</strong>nia Cascades -…-…-…-…- - -Cali<strong>for</strong>nia Klamath…-…---Cali<strong>for</strong>nia Coast- …--rCali<strong>for</strong>niaFigure 2.2. Provinces within <strong>the</strong> range of <strong>the</strong> nor<strong>the</strong>rn spotted owl in <strong>the</strong> United States.32
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