RESULTS OF BOREAL OWL (Aegolius funereus) SURVEYS ON THE JEFFERSON DIVISION OF THE LEWIS & CLARK NATIONAL FOREST by JOHN C. CARLSON I I lift Montana Natural Heritage Program 1515 East Sixth Avenue Helena, Montana 59620 for the U.S.D.A. Forest Service Lewis and Clark National Forest Great Falls, Montana 59403 Cooperative Challenge Cost Share Program Montana Natural Heritage Program Lewis and Clark National Forest April 1991 I I I I I I I I I I I I I I I I I I I Cover drawing by John Carlson 19 91 Montana Natural Heritage Program This document should be cited as follows: Carlson, J.C. 1991, Results of boreal owl (Aeqolius funereus) surveys on the Jefferson Division of the Lewis and Clark National Forest, Montana. Montana Natural Heritage Program. Helena, MT. 33 pp. ACKNOWLEDGEMENTS I The financial support for this survey was provided by the Montana Natural Heritage Program and the Lewis and Clark National Forest through the Challenge Cost Share Program. I wish to thank Dave Genter, MTNHP, for allowing me to do this survey. Bob "Chief Two Hoots" Gliko, USFS, was my native guide and the best help I could have hoped for. Don Sasse, USFS district biologist was very helpful with suggestions and guidance during the survey. Kurt Pettersson, Julie Evans, Marie Karlson, Don Godtel, Don Sasse, Dana Fields, Dave Genter, Burt Lindler, Kristi DuBois, and Pat Finnegan all participated at one time or another in the survey - thank you. I The entire staff at the Belt Creek Information Station was very helpful. The U.S. Forest Service provided me with a quiet place to stay during the survey and all the equipment we used. Thanks to Scott Jackson, John Malloy, and Dave Genter for reviewing this document and Margaret Beer for helping me with the computer. I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I TABLE OF CONTENTS Page LIST OF TABLES AND FIGURES ii ACKNOWLEDGEMENTS iii OBJECTIVES 2 INTRODUCTION 3 SURVEY AREA 5 METHODS 7 RESULTS 10 DISCUSSION 16 CONCLUSION AND RECOMMENDATIONS 18 REFERENCES 20 APPENDICES APPENDIX 1 22 APPENDIX 2 25 I I I I I I I I I I I I I I I I I I I LIST OF TABLES NUMBER PAGE 1 - Owl survey routes and lengths 11 2 - Owl observations, 1991 12 LIST OF TABLES 1 - Distribution of the boreal owl by counties in Montana.... 4 2 - Map of survey area, Kings Hill Ranger District, Lewis and Clark National Forest 6 3 - Locations of survey routes within the study area, 1991... 8 li I I I ACKNOWLEDGEMENTS I I The financial support for this survey was provided by the Montana Natural Heritage Program and the Lewis and Clark National Forest through the Challenge Cost Share Program. I wish to thank I Dave Genter, MTNHP, for allowing me to do this survey. Bob "Chief Two Hoots" Gliko, USFS, was my native guide and the best help I could have hoped for. Don Sasse, USFS district biologist was very helpful with suggestions and guidance during the survey. Kurt Pettersson, Julie Evans, Marie Karlson, Don Godtel, Don Sasse, Dana Fields, Dave Genter, Burt Lindler, Kristi DuBois, and Pat Finnegan all participated at one time or another in the survey - thank you. The entire staff at the Belt Creek Information Station was very helpful. The U.S. Forest Service provided me with a quiet place to stay during the survey and all the equipment we used. Thanks to Scott Jackson, John Malloy, and Dave Genter for reviewing this document and Margaret Beer for helping me with the computer. I I I I I I I I I I I I I 111 I I I SUMMARY A survey for boreal owls was conducted on the Lewis and Clark National Forest in the Little Belt Mountains of central Montana during February and March of 1991. The call playback method was ■ used to survey for owls on 19 nights. A total of 13 survey routes were established, encompassing 87 calling points and 70.2 miles. Some routes were surveyed more than once for a total of 88.5 miles. I All owl observations were recorded and mapped. Habitat classifications were obtained from timber typing maps for all I boreal owl locations. Boreal owls were heard at 8 calling points, represented 6 individuals. All but one were located in lodgepole pine (Pinus contorta ) timber types. The other was in a whitebark I pine (Pinus albicaulis ) timber type. All were located between 6400 ft. and 8088 ft. in elevation. Other owl species located, in order of abundance, were northern saw-whet ( Aegolius acadius) , great ■ horned ( Bubo virqinianus ) , barred (Strix varia) , great gray (Strix nebulosa) , and a western screech owl (Otus kennicottii ) . Surveys I are recommended for at least 3 more years in the Little Belt Mountains to accurately determine the population characteristics and habitat used by boreal owls. I I I I I I OBJECTIVES The 1991 surveys for boreal owls were initiated to document the occurrence of, and habitat used by boreal owls on the Jefferson Division of the Lewis and Clark National Forest. Similar data were to be gathered for other owl species present. These data will assist in forest planning and will contribute in the assessment of distribution, population dynamics and viability of the boreal owl on the Lewis and Clark National Forest. I I I I INTRODUCTION The boreal owl ( Aegolius funereus ) is a highly nocturnal owl I which inhabits northern hemisphere coniferous forests around the world. They are generally 21.5 to 30.5 cm long (Farrand 1983) and weigh 100-140 gm (Earhart and Johnson 1970) . Boreal owls are small, ■ brown owls with many white spots on their crown, nape, and back. Yellow eyes and a yellowish bill are framed by distinctive black I facial frames which are spotted with many small white spots. Their white underparts are streaked with chocolate brown. Juveniles are I dark chocolate brown with white spots across the back and white eyebrows and cheek spots. Boreal owls are secondary cavity nesters, usually occupying cavities constructed by the northern flicker ( Colaptes auratus) or pileated woodpecker ( Dryocopus pileatus ) . Boreal owls will also use artificial nesting boxes (D. Genter per. coram.). Boreal owls are territorial and a nesting pair will actively defend the area around the nest site (D. Genter per. comm.). After the courtship in March and April, 4 to 6 pure white eggs are laid. The eggs are incubated for 27-28 days by the female and the young fledge 28-33 days after hatching (Terres 1980). Boreal owls prey mainly on small mammals, primarily redback voles ( Clethrionomys gapperi ) but also pocket gophers ( Thamomys talpoides ) , shrews ( Sorex spp.), and deer mice ( Peromyscus maniculatus ) . Some insects and birds are also eaten (Hayward et al. 1987). I The owls are generally secretive throughout the year, residing I I Slat* Csniiai Csvnty S«ati * Cltlai on* Towni • POPULATIONS Of C0MMUNim3 W SOURCES raf at (HurtiriM, tti ■ tflar U.t.11 MONTANA □ KNOWN O PROBABLE * OWL LOCATION I I Figure 1. Distribution of the boreal owl in Montana, 4 in mature spruce/fir forests of North America, but are easily located during the courtship period by conducting nocturnal surveys using the call playback technique (Palmer 1987) . Once thought to exist only as isolated Pleistocene relict populations at high elevations in the Rocky Mountains (Baldwin and Koplin 1966), breeding populations were found in the 1980 ! s in Idaho (Hayward 1983), Colorado (Palmer 1987), and Montana (Holt and Ermatinger 1989) . Recent surveys have revealed boreal owls throughout the Rocky Mountains (Hayward et al . 1987, O'Connell 1987) . Boreal owls have been located throughout most of western Montana and may be quite common in certain habitats (Holt and Ermatinger 1989, Mullen 1990) (Fig. 1). The lack of knowledge of boreal owl distribution was probably because of the inaccessability of high elevations during March and April, when boreal owls are most easily detected. Region 1 of the U.S. Forest Service lists the boreal owl as a sensitive species and therefore is required by the National Forest Management Act to monitor it's status and provide habitat to ensure viable populations on national forest lands throughout their range (U.S. Department of Agriculture, 1986). Boreal owls were not known to occur on the Lewis and Clark National Forest in the Little Belt Mountains, but the presence of suitable habitat suggested they may be present and led to this survey. SURVEY AREA Surveys were primarily conducted on the Kings Hill Ranger I I Figure 2. Map of survey area, Kings Hill Ranger District, Lewis and Clark National Forest. I I I I I I I I District of the Jefferson Division on the Lewis and Clark National Forest (Fig. 2) . The Kings Hill Ranger District lies in the Little Belt Mountains of central Montana. The Little Belt Mountains are dome-like with smooth rounded tops flanked by valleys. They are composed of an igneous rock core with sandstone, limestone, and shale exposed on the higher ridges. The north and south facing slopes are uplifted and tilted limestone beds (U.S. Forest Service 1986) . Elevations range from 4500 ft. along the Smith River to 9200 ft. at Slide Rock Point. Lower elevations of the district are dominated by Douglas fir ( Pseudotsuga menziesii ) forest with small grassland parks on exposed ridges and steep south facing slopes. Middle elevation areas are dominated by lodgepole pine (Pinus contorta) . Aspen (Popjolus tremuloides ) , Douglas fir, and spruce (Picea englemannii ) are also found. High elevation areas are severely affected by high winds. Trees tend to be shorter than normal, big boled with dense limbs extending to the ground. Lodgepole pine mixed with stands of whitebark pine ( Pinus albicaulis ) , spruce, Douglas fir, and subalpine fir ( Abies lasiocarpa ) are the major tree types at high elevations. Alpine meadows are interspersed with trees along the ridges . Annual precipitation ranges from 14 in. on the lower slopes to 50 in. on the higher peaks. METHODS Forest Service technician Bob Gliko and I surveyed owls using 7 the call playback technique (Fuller and Mosher 1981) from vehicles, snowmobiles, and skis along selected survey routes between February 21 and March 27, 1991. Survey routes were primarily at elevations higher than 5000 ft. and in areas with large patches of old growth forests (Figure 3) . Routes were selected and prioritized based upon conversations with Forest Service Biologist Don Sasse. Surveys were started one half hour after sunset and lasted approximately 4 to 5 hrs, weather permitting. Playback stations were one half to 1 mile apart along the survey route. The spacing varied widely on some routes due to the topographic and/or habitat variation. Some survey routes were completed in their entirety on a single night, others were completed in segments surveyed on different nights. Therefore some segments of survey routes overlapped and were surveyed more than once, other portions only once. Time and estimated wind speed and direction were recorded at each calling station. Temperature was recorded at the first and last calling station each night. Elevation of each calling station was determined from topographic maps. At each station we listened for calling owls for 2 to 3 minutes, played 1 species call in all 4 directions for 2 to 3 minutes, listened for 2 to 3 minutes, and then repeated the procedure. Boreal owl calls were played most often, but occasionally great gray (Strix nebulosa ) or northern saw-whet ( Aegolius acadius ) calls were also used depending on habitat and calling responses. Survey report forms were completed for each survey conducted and owl observation forms were completed for each owl heard (Appendix 1) . All calling points and owl locations were recorded on 7.5 minute U.S.G.S. topographic maps along with the date and time for each calling point and observation (Appendix 2) . Calling points were numbered with the route number followed by the calling point number. Owl locations were described according to the timber type of the stand the owl was located in. These types are named for the major volume species in the stand, regardless of tree size, and other species of trees may be present. RESULTS Surveys were conducted on 19 nights during the survey period. Weather, especially wind, caused some of the 19 surveys to be cut short and resulted in total survey cancellation on other nights. A total of 15 survey routes were established which totaled 70.2 miles and encompassed 87 calling points. The total number of miles surveyed was 82.6 miles (Table 1). The elevation of calling points ranged from 4720 ft. to 8088 ft. Temperatures during the surveys ranged from 14 to 3 6 degrees Fahrenheit. Boreal owls were detected at 8 calling points with a minimum of 6 birds detected. Northern saw-whet owls were the most common owl detected, being heard at 12 stations with a minimum of 14 birds detected. Seven great horned owls ( Bubo virainianus ) were detected at 5 stations. Two barred owls (Strix varia) were repeatedly located in one area from 3 calling stations and a great gray owl and western screech owl ( Otus kennicottii l were located at one calling point each. One unknown owl call was heard at one calling station (Table 2) . 10 # ROUTE NAME MILES N 1 PAINE GULCH 1.2 1 2 DRY FORK 7 1.5 3 WILLIAMS PARK 10 1 4 ISLAND PARK 6.3 1 5 MOOSE CREEK 9 1 6 O'BRIAN 4.7 1 7 JEFFERSON 3 1 8 MOOSE MT. RIDGE 1.9 2 9 MOOSE MT./BLACK FOREST 1.3 1 10 HIGHWAY 9.4 2 11 DEADMAN 8.1 1 12 ALLEN GULCH 3.5 2 13 HIGGENS PARK 4.8 1 TOTAL MILES SURVEYED 1.2 10.5 10 6.3 9 4.7 3 3.8 1.3 18.8 8.1 7 4.8 TOTAL 70.2 16.5 88.5 Table 1. Owl survey routes and lengths, 1991 11 species calling point date ( elevation time i aspect i lumber moon Boreal 5-009 2/24/91 6700 2045 NW 1 FQ Boreal 8-026 2/26/91 8080 1900 S 1 FM Boreal 10-034 3/8/91 6400 2225 N 1 LQ Boreal 8-037 3/11/91 7400 2300 SW 1 LQ Boreal 13-053 3/13/91 7840 2333 s 1 NM Boreal 13-054 3/13/91 7840 7 s 1 NM Boreal 3-065 3/15/91 6680 2237 w 1 NM Boreal 3-066 3/15/91 6640 2204 w 1 NM Northern Saw- Whet 10-031 2/21/91 5400 2055 NE 1 FQ Northern Saw- Whet 10-031 2/21/91 5400 2135 NE 1 FQ Northern Saw- Whet 10-034 3/2/91 5960 1900 N,S 3 FM Northern Saw- Whet 2-072 3/4/91 5960 1914 N 2 FM Northern Saw- Whet 2-070 3/8/91 6320 2225 N 1 LQ Northern Saw- Whet 2-069 3/8/91 6160 2129 NW 1 LQ Northern Saw- Whet 2-068 3/8/91 6920 2049 W 1 LQ Northern Saw- Whet 2-075 3/19/91 5600 2133 s 1 NM Northern Saw- Whet 2-076 3/19/91 5240 2207 s 1 NM Northern Saw- Whet 1-002 3/19/91 5240 2240 SW 1 FQ Northern Saw- Whet 1-003 3/19/91 5160 2252 SW 1 NM Northern Saw- Whet 12-060 3/20/91 5000 2130 NE 1 FQ Northern Saw- Whet 12-061 3/20/91 4840 2145 NE 1 FQ Great Horned 1-001 2/21/91 5100 2025 S 2 FQ Great Horned 2-075 3/14/91 6200 45 S 1 NM Great Horned 3-067 3/14/91 6200 2303 SE 1 NM Great Horned 12-056 3/15/91 6500 2131 NW 1 NM Great Horned 12-052 3/20/91 4960 2130 - 2 FQ Barred 10-031 3/2/91 6500 1900 N 1 FM Barred 10-031 3/2/91 5920 1900 - 1 FM Barred 10-031 3/4/91 6100 1918 NW 1 FM Barred 7-060 3/8/91 6500 2129 NE 1 LQ Barred 7-060 3/8/91 6200 2129 W 1 LQ Great Gray 12-069 3/19/91 5300 2240 N 1 FQ Great Gray 12-069 3/20/91 5300 2040 N 1 FQ Western Screech 3-073 3/19/91 5480 2100 - 1 NM Unknown 10-032 3/2/91 6080 2035 _ 1 FM Table 2. Owl observations, 1991, 12 Boreal Owl Detections Boreal owls were located at elevations from 6,400 ft. to 8,080 ft. Aspects of owl locations ranged were 3 on south facing slopes, 2 on west facing slopes, and one each facing northwest, north and northeast. All were located in response to song playback. All boreal owls located were in lodgepole pine stands except for one in a whitebark pine stand. Calling point 7-009, 2/24/91, 8:45 pm, Moose Creek Route. This was the first owl we detected. The owl responded to song playback after the second calling sequence and continued to call until we left the area. It was located on Moose Creek near the confluence of Moose Creek and Rocking Chair Creek (T13N,R7E, sect . 24 ,SWl/4 ,NEl/4) at 6700 feet. The owl's location was estimated to be in stand 711-06-85 which is classified as lodgepole, well stocked. Calling point 7-026, 2/26/91, 11:00 pm, Moose Mountain Ridge Route. This owl was heard while skiing to the next calling point after completing a calling sequence. The owl was located at approximately 7840 feet (T12N,R7E / Sect.2,NEl/4,NEl/4) , then moved up to the ridge (T13N,R7E,Sect.36,SWl/4,SWl/4) at 8,080 feet and called again. It continued calling until we tried song playback again five minutes later. The owl was initially located 13 in stand 709-02-20 which is classified as mixed conifer, well stocked, and flew in response to song playback to stand 709-02-02, lodgepole, poorly stocked. Calling point 7-034, 3/8/91, 10:25 pm, Highway Route. This owl was heard after the second playback sequence. The owl responded only twice so the location is not precise. We estimated that the owl was located at the bottom of Deadman Creek (T12N,R8E,Sect. 23 ,NEl/4 ,SWl/4 ) at 6400 feet. The owl ceased calling when a northern saw- whet owl started calling near the calling point. The boreal owl was estimated to be in stand 702-02-42 which is lodgepole, medium stocked. Calling point 7-037, 3/11/91, 11:00 pm, Highway Route. We located this owl near the highway at the top of Kings Hill Pass near the Forest Service rental cabins (T13n, R8E, Sect. 34, El/2, SW1/4) . The owl responded to the initial song playback and was located immediately south of the calling point within 200 ft. The owl called a number of times and appeared to move around the edge of the hill while we were listening. This owl was located in stand 702-04-29 which is lodgepole, well stocked. Calling points 7-053 and 7-054, 3/13/91, 11;33 pm to 12:07 am, 14 Higgens Park Route. We heard this owl in response to initial playback at both calling stations. It remained in the same location (T12N,R8E,Sect . 36,NWl/4 ,SEl/4) , and called vigorously. This was the only boreal owl located in a whitebark pine stand, stand number 701-02-04, and was the only boreal owl that did not move in response to song playback. This was also the only location where we heard a boreal owl and great horned owls in close proximity. Calling points 7-065 and 7-066, 3/15/91, 10:04 pm to 10:37 pm, Williams Park Route. This location provided the only visual observation of a boreal owl during the survey. The owl was initially heard giving an OOO-WEE call at calling point 7-066 (T13N,R6E,Sect.20,NEl/4,NEl/4) . The owl then followed the surveyors to the next calling point 7-065 (T13N,R6E,Sect.l6,SWl/4,NWl/4) , where it was observed calling in a tree adjacent to the road. There the owl was heard giving the typical winnowing call. The owl was initially located in stand 713-05-009, which is classified as lodgepole, well stocked and moved to stand 713-05-29, which is also classified as lodgepole, well stocked. 15 DISCUSSION Intensive studies by Hayward et al. (1987) and Bondrup - Nielson (1984) , show only potentially breeding males call, implying that the presence of calling owls indicates a breeding population. Therefore, the presence of calling boreal owls in the study area indicates that boreal owls nest in the Little Belt Mountains, The results of this survey should only be considered an indication of boreal owl activity and locations since the data gathered cannot be used to provide estimates of population levels or density within the study area. Factors affecting the responses of boreal owls to call playback survey techniques are numerous. The single most important variable negatively affecting response is wind (Smith 1987 and Palmer 1987) . We experienced numerous evenings that the wind canceled or shortened surveys and therefor we did not cover some areas that we feel have potential for boreal owl observations. The only previous surveys attempted on the district ended without any calling on three nights due to high winds and snow (Escano 1984) . All boreal owl locations in this survey except one were in timber stands classified as lodgepole. The other was in a whitebark pine stand. These findings are different than those found in the Bitterroot Divide (Holt and Hillis 1987) , central Idaho (Hayward et. al. 1984), and southwest Montana (Mullen 1990) which all found boreal owls in spruce/fir forest types, although Escano (1984) reported that surveys on the Beaverhead National Forest located 4 16 I I boreal owls in lodgepole pine habitat types with scattered meadows or grass/sage openings. This discrepancy with the prevalent habitat type reported may be due to the limited amount of spruce/fir stands available at higher elevations in the Little Belt Mountains, or may be a factor of the habitat classification methods used in this survey . Boreal owls in the Little Belts may have problems with warm summer temperatures since boreal owls are easily heat stressed I (Hayward et al. 1987). Therefore, dense stands of timber which would provide cool moist sites for roosting may be important to I boreal owls in the Little Belts. Also the high level of wood cutting on the district (Sasse pers. com.) may limit the availability of suitable nesting snags for boreal owls. Hayward I (pers. comm. in Mullen 1990) suggested that clearcuts may provide edge habitat used by owls for hunting. However, Mullen (1990) I warned that man-made openings also are often accompanied by the potential for increased human disturbance and the invasion of competing owl species, especially great horned owls. I Boreal owls have extremely variable calling activity (Hayward et al. 1986, Palmer 1987). Variations in prey populations directly influence calling activity by reducing breeding activity during periods of low prey populations (Hayward 1987) . Bondrup and Nielsen (1978) found that pair formation will also cause the male to stop calling. Hayward (1983) noted that one male did not respond to surveys during the normal courtship period because he was already paired. Palmer (1987) found courtship periods ranging from 4 to 59 17 days with the longest courtship periods found for unpaired males. The variability in boreal owl calling activity shows that we can not effectively determine population dynamics of the boreal owl in the Little Belts from 1 survey season. CONCLUSIONS AND RECOMMENDATIONS This survey confirms that boreal owls are present in the Little Belt Mountains and expands the known range of the boreal owl I into the isolated mountain ranges of central Montana. Hayward (1987) noted that the potential vulnerability of local populations I to extinction depends upon, the degree of interchange among denies. I Determining and providing for the required degree of interchange may be especially important to populations in isolated mountain I ranges such as the Little Belts. Boreal owls may also be present in the other isolated mountain ranges of central Montana such as the I Crazy, Castle, Snowy and Judith Mountains. Surveys in the proper ■ habitats in these mountain ranges would be beneficial to determine the eastern extent of boreal owls in Montana and the geographical I relationship of boreal owl populations to one another. Further investigations into the exact vegetative composition of the stands owls were located in would be beneficial. Since boreal owls generally use only conifer snags over 21" diameter at breast height in forested stands as nesting cavities (Hayward I 1990) , an upper size limit for conifers cut for firewood in high elevation areas may be considered. Small mammal surveys should also I be conducted to determine the small mammal species occupying the Little Belts that may be prey items for boreal owls. As Mullen (1990) pointed out, short term surveys such as this do not take into account the yearly variation in boreal owl calling rates and any management directed solely by this one year of study may be harmful. Additional survey years may yield owl observations in areas that did not result in boreal observations this year. At least 4 years of surveys should be conducted to effectively determine boreal owl distribution in the area (Mullen 1989) . Repeat surveys and additional surveys should be conducted, extending through April to better cover the study area. Emphasis should be placed on locating nest sites to gain a better idea of breeding habitat in the Little Belts. 19 REFERENCES Baldwin, P.H. , and J.R. Koplin. 1966. The boreal owl as a Pleistocene relict in Colorado. Condor 68:299-300. Bondrup-Nielson, S. 1984. Vocalizations of the boreal owl (Aegolius funereus richardsoni) in North America. Canadian Field- Naturalist 98 (2):191-197. Earhart, CM. and N. K. Johnson. 1970. Size dimorphism and food habits of North American owls. Condor 72 (3) : 251-264 . Escano, R. 1984. Boreal owl survey summary: wildlife and fish habitat relationships program, Northern Region. U.S. For. Ser. , Reg. Off., Missoula, MT. 11 pp. Farrand, J. 1983. Audubon Society Master Guide to Birding, No. 2 Gulls to Dippers. Alfred A. Knopf, Inc. New York. New York, pp 176-178. Fuller, M.R. and J. A. Mosher. 1981. Methods for detecting and counting raptors: a review, pp. 235-246. In: C.J. Ralph and J. Scott (eds) ; Estimating the numbers of terrestrial birds. Stud. Avian Biol. 6. Hayward, G.D. and E.O. Garton. 1983. First nesting record of the boreal owl in central Idaho. Condor 85:501 Hayward, G.D., P.H. Hayward, E.O. Garton, and R. Escano. 1987. Revised breeding distribution of the boreal owl in the northern Rocky Mountains. Condor 89:431-432. Hayward, G.D., P.H. Hayward, and E.O. Garton. 1987. Movements and home range use by boreal owls in central Idaho, pp 17 5-18 5 in: R.W. Nero, R.J. Clark, R.J. Knapton, and R.H. Hamre, eds. Biology and conservation of northern forest owls: symposium proceedings. Gen. Tech. Rep. RM-142. Fort Collins, CO. U.S. Dept. Agric, Forest Service, Rocky Mountain Forest and Range Exp. Stat. , 309 pp. Hayward, G.D., P.H. Hayward, and E.O. Garton. 1987b. Habitat requirements and distribution of the boreal owl in central Idaho. Annual Progress report. Dept. of Fish and Wildlife Resources, College of Forestry, Wildlife and Range Sciences, University of Idaho, Moscow, ID. 11 pp. Hayward, G.D. 1990. Note on file. U.S. Forest Service, Lewis and Clark National Forest, Belt Creek Information Station, Neihart MT, 2 pp. 20 Holt D., and J.M. Hillis, 1987. Current status and habitat association of forest owls in Montana, pp 281-288 in: R.W. Nero, R.J. Clark, R.J. Knapton, and R.H. Hamre, eds . Biology and conservation of northern forest owls: symposium proceedings. Gen. Tech. Rep. RM-142. Fort Collins, CO. U.S. Dept, Agric, Forest Service, Rocky Mountain Forest and Range Exp. Stat. , 309 pp. Holt, D. and D. Ermitanger. 1989. First confirmed nest of boreal owls in Montana. Northwest Naturalist 70:27-31 Mullen, P. 1989. Status report on boreal owl surveys in southwestern Montana, 1989. MT Natural Heritage Program, Helena, MT. 23 pp. O'Connell, M.W. 1987. Occurrence of the boreal owl in northeastern Washington, pp 185-189 in: R.W. Nero, R.J. Clark, R.J. Knapton, and R.H. Hamre, eds. Biology and conservation of northern forest owls: symposium proceedings. Gen. Tech. Rep. RM-142. Fort Collins, CO. U.S. Dept. Agric, Forest Service, Rocky Mountain Forest and Range Exp. Stat., 3 09 pp. Palmer, D.A. 1987. Annual, seasonal, and nightly variation in calling activity of boreal and northern saw-whet owls, pp 162- 169 in: R.W. Nero, R.J. Clark, R.J. Knapton, and R.H. Hamre, eds. Biology and conservation of northern forest owls: symposium proceedings. Gen. Tech. Rep. RM-142. Fort Collins, CO. U.S. Dept. Agric, Forest Service, Rocky Mountain Forest and Range Exp. Stat., 3 09 pp. Smith, D.G. 1987. Owl census techniques, pp 304-307 in: R.W. Nero, R.J. Clark, R.J. Knapton, and R.H. Hamre, eds. Biology and conservation of northern forest owls: symposium proceedings. Gen. Tech. Rep. RM-142. Fort Collins, CO. U.S. Dept. Agric, Forest Service, Rocky Mountain Forest and Range Exp. Stat., 3 09 pp. Terres, J.K. (ed) . 1980. The Audubon Society Encyclopedia of North American Birds. Alfred A. Knopf Inc. New York. 1109 pp. U.S. Department of Agriculture. 1986. Lewis and Clark National Forest Plan Environmental Impact Statement. Lewis and Clark National Forest, Great Falls, MT 391 pp. 21 APPENDIX 1 22 SURVEY REPORT FORM Party Members Route location: Drainage Repeat Visit ? Date Route Name County Elevation Y N Target Species (if any) Forest District Route Description Distance: Means of travel: (auto, ski, etc.) Start time: Finish time: Weather (at end of survey) Temperature: Cloud cover: Snow depth: Precipitation (describe) Wind: Species encountered (if any, use Owl Observation Form) species # 23 OWL OBSERVATION FORM Party Members Date Route Name Repeat Observation ? Y N Species Location: TRS: County: Drainage: Number present Slope Time to Aspect Elev Forest: District: Describe Observations: Describe Location: Describe Habitat: Describe Land use/management: Comments : 24 APPENDIX 2 25 Calling point 7-009 26 Calling point 7-026 27 Calling point 7-034 28 Calling point 7-037 29 Calling points 7-053 and 7-054 30 Calling points 7-065 and 7-066 31