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Distribution of the Boreal Owl in Eastern Washington and Oregon’

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Distribution of the Boreal Owl in Eastern Washington and Oregon’ 712 SHORT COMMUNICATIONS movement for cooling, and was a suitable substratefor nest construction for ravens and other birds. Both nest siteswere in flat to rolling terrain ofdesert- shrub habitat. No suitable natural nesting sites (cliffs) were within a 5- to lo-km radius of the nestingtowers. Thus, abandonedraven nestsin towers have provided suitablenesting sites for Prairie Falconswhere a natural site was lacking. LITERATURE CITED BEN-~,A. C. 1938. Life histories of North American birds of prey. Part 2. Dover Publications, New York. CADE, T. J. 1982. The falcons of the world. Com- stock/Cornell Univ. Press, Ithaca, NY. MACLAREN, P. A., D. E. RUNDE,AND S. H. ANDERSON. 1984. A record of tree-nesting Prairie Falcons in Wvomina. Condor 86:487488. FIGURE 2. Young Prairie Falconsin abandoned ra- ODGEN;V. T.r~tm M. G. HORNOCKER.1977. Nesting ven nest on a transmission tower. density and successof Prairie Falcons in south- western Idaho. J. Wildl. Manage. 41:1-l 1. OLENDORFF,R. R., A. D. MILLER,AND R. N. LEHMAN. spection of the nest indicated that it was unoccupied. 1981. Suggestedpractices for raptor protection On tower no. 294, a Prairie Falcon was observed in- on power lines; the stateof the art in 1981. Raptor cubatingon a stick nest. This site was in the sametower ResearchReport 4: l-l 11. position as the 1985 nest, but was approximately 4.8 PALMER,R. S. [ED.] 1988. Handbook of North Amer- km southwest of tower no. 322. On 17 June 1986, ican birds. Vol. 5. Diurnal raptors (Part 2). Yale observersclimbed the tower and found two youngbirds Univ. Press, New Haven, CT. (30-35 days old) in the nest. Both adults were present. POSTOVIT,H. R., AND B. C. POSTOVIT.1987. Impact The tvpical falcon nest is on a cliff with some dearee and mitigation techniques,p. 183-2 13. In B.A.G. of overhead protection and shading(Cade 1982, Palm- Pendleton, B. A. Millsap, K. W. Cline, and D. M. er 1988). The falconsfound in abandoned raven nests Bird [eds.], Raptor managementtechniques man- were surroundedby the metal lattice of the tower (Fig. ual. Natl. Wildl. Fed., Scientific and Technical Se- 2). The latticework provided shading, allowed air ries No. 10. TheCondor91:712-716 0 The CooperOrnithological Society 1989 DISTRIBUTION OF THE BOREAL OWL IN EASTERN WASHINGTON AND OREGON’ BARTLET-~D. WHELTON Department of Chemistryand Biochemistry,Eastern WashingtonUniversity, Cheney, WA 99004 Key words: Aegolius funereus; Boreal Owl; distri- in Whatcom County during January 1905 (Dawson bution; westernNorth America. 1908). Since that time the owl’s presence has been verified by a specimen taken during January 1974 in In its description of the southern distributional limit Whitman County, paradoxically the heart of Wash- for the Boreal Owl (Aegoliusfunereus)in North Amer- ington’s wheat land (Johnson and Hudson 1976). To ica, the AOU (1983) noted continuous populations date records from Oregon have included a number of acrosssouthern Canada and isolated ones from north- referencesdescribing its presenceduring the 1800s as western Wyoming and north-central Colorado. Until “not rare” in the Oregon Territory and-a single spec- the 1970s the specieswas singularly known in Wash- imen taken in Klamath Countv durina March 1902 ington State from a now misplacedspecimen collected (Gabrielson and Jewett 1940). -More recently Boreal Owl surveysin statesalong the Rocky Mountain cor- ridor from northern New Mexico to northern Idaho I Received 12 August 1988. Final acceptance 30 and Montana have revealed a not so discontinuous March 1989. pattern of breeding populations (Palmer and Ryder SHORT COMMUNICATIONS 713 1984, Hayward et al. 1987, and Rawinski and Stah- and breast. These included bright lemon-yellow irises, lecker in Hubbard 1987). Thus in an effort to assess whitish loresand superciliaries,whitish facial discswith the statusof the speciesin areasalong the western edge prominent black bordersarcing over and down through of the Rockies south of the U.S.-Canadian border, sur- the tops and insidesof the eyesand forming a “stirrup” veys were undertaken in the Kettle River and Selkirk about the base of the bill, charcoal smudge marks on ranges of northeastern Washington and the Blue and the lower, outer quadrantsof the discs, whitish breast Wallowa mountains of southeasternWashington and vertically streakedby broad, sometimes broken, choc- northeastern Oregon. olate-brown bands. and a pronortionatelv large. earless head topped by a fiat or siighily concave-crown.Other METHODS AND RESULTS marks noted on nearby and/or well-illuminated birds From March to October 1985, 2 1 hiking surveyswere were the straw/olive colored bill and the dense white conductedin five subalpinesites located on the Kettle spottingof the forehead, black disc border, and crown Crest,Ferry County and the Salmo Divide, Pend Oreille (finest markings reserved to the former two areas). County, Washington.These mixed coniferoussites were Of 33 contactsestablished over the year, a minimum respectivelydominated by multiple-agedlodgepole pine of 23 individual Boreal Owls were located (Table 1) of (Pinus contorta) or subalpine fir-Engelmann spruce which 14 were seen including seven perched. The first (Abies lasiocarpa-Piceaengelmannii) forest and were encounteredwas a staccato-callingmale found on the situatedat elevationsbetween 1,525 and 1,950 m. Ap- Kettle Crest in April; suchactivity is indicative of po- proximately 6 km of trail or gravel road traversedeach tential individual breeding and the presenceof breed- area. Two additional censuseswere taken in a sixth, ing populations (Bondrup-Nielsen 1984, Palmer and lower site (945 m) of similar habitat type along the Ryder 1984, and Hayward et al. 1987). This however Little Pend Oreille River, StevensCounty, during De- was the only courting male found during 1985. Ad- cember 1985 and January 1986. Boreal Owls were lo- ditional vocalizationsgiven by this owl included a sin- cated in all seasonsby responseto a taped recording gular chuukcall and an excited, upbeat version of the of the male’s staccutocall (M. B. Dickinson, Ed., Guide slacculocall. The third and fourth located were an to Bird Sounds,National Geographic Society, Wash- apparentpair found on the Salmo Divide. One or both ington, DC, 1983) played on a small tape recorder (7.5 were contactedin the sameimmediate areaon a monthly cm speaker diameter) at middle to high volume at basis from June through September and were accom- approximately 200-m intervals. Interval stops aver- panied by at least one additional but unseenowl during aged 5+ min. Surveys were generally conducted be- the last 2 months. Whether particular to this pair or tween waxing one-half to waning three-fourths moon not, they would only answer the recorder within an phases.Responses, as described by Bondrup-Nielsen approximate 75-m radius of what appearedto be their (1984), included the staccatocall (the courtship song area center, presumablya nest site. During the August given exclusivelyby the male typically from mid-March visit, both were observed intermittently over a 5-hr through mid-May), the skiew and moo-u calls (aggres- period. Two principal vocalizations were repeatedly sive, threatening,distress or alarm callsapparently giv- elicited in response to the taped staccatocall; these en most frequently by the male), the chuukand peeping were heard individually and at times simultaneously calls (contact calls issued apparently by the female on and were recorded. The recordingswere digitally ana- or near the nest in responseto staccatovocalizations lyzed by computer as sonograms (DEC PDP 1 l/23 from the male), and the chatter call (the distress call computer programmed with “Interactive Laboratory of the juvenile). Systems,” May 1985 by Signal Technology, Inc., 595 1 In general, visual observationsof Boreal Owls were Encina Road, Goleta, CA) and were favorably matched more readily accomplishedwhen at least two observers with those for the moo-a and chuuk calls as identified were in the field. The quality of observations varied by Bondrup-Nielsen (1984). In addition these vocal- from those of moonlit owls aggressivelyflying directly izations were found to be equivalent to those noted at the face of the tape recorder holder or on occasion respectively as the “alarm” and “aggressive” calls in gliding immediately overhead (distancesclosing ulti- Europeanrecordings of Tengmalm’s Owl (Aegoliusfu- mately to less than 2 m), to those that circled the re- nereus)from S. Palmer and J. Boswall’s, A Field Guide corder (distancesof 15 to 25 m), to two separatein- to the Bird Songsof Britain and Europe (Swedish Ra- dividuals viewed on unobstructed perches under full dio). Later that same evening, an approximate S-min- spotlightillumination for as long as 15 min (minimum long multiple ofstaccatoresponses was eventually elic- distancesof 2 and 4 m). Owls aggressivelyapproaching ited from the owl giving the chuuk call. During the the recorder frequently perched nearby (10 to 20 m) September visit, the first of the three owls contacted on open branches,however they typically would only respondedwith a subduedchuuk followed by about 10 allow brief spotlight illumination (5 to 10 set). Those min of intermittent moo-ucalls. Responsesof the other circling the recorder were usually most resistantin af- two were singularly restricted to either the chuuk or fording visual identification other than by size (length chattercall. Attempts to find nestsat this and the Kettle and wingspan about 25 and 60 cm, respectively and site were unsuccessful.During the
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