EXECUTIVE SUMMARY
We conducted a pilot study in 1999 to evaluate proposed methods for monitoring population trend of the Mexican spotted owl in Arizona and New Mexico. Primary objectives of this pilot study were to: (1) collect preliminary data to estimate spatial variation in owl density; (2) use that preliminary data to estimate sample-size requirements for long-term monitoring; and (3) evaluate the feasibility of conducting a mark-recapture study of spotted owls at a broad spatial scale. This is an interim report summarizing our initial field observations. It is intended to provide information for land managers, contains no formal analysis of preliminary data, and thus does not address the above objectives.
The pilot study involved mark-recapture sampling of spotted owls on 25 randomly-located study "quadrats" ranging from approximately 40-76 km2 (15-30 mi2) in area. With a few exceptions, quadrats were thoroughly surveyed 3 or 4 times, depending on whether or not any spotted owls had been located by the end of the third survey pass (quadrats lacking owl detections by then were not surveyed a fourth time). This resulted in a total of 8,257 calling points surveyed (including repeat visits to 2,345 unique call points on 3-4 survey passes). Spotted owls were heard or seen on 18 quadrats. Spotted owls were heard from 434 call points, resulting in 400 daytime follow-up surveys. Owls were located on 202 of these followup surveys. Using conservative criteria to designate territories, we estimated that the owls located represented a minimum of 47 confirmed and 6 suspected territories. This included 8 territories where owls were detected within the quadrat, but the activity center (nest and/or major roost area) was suspected to lie outside the quadrat boundary. We located 64 juvenile owls and banded 23 of these. In addition, 57 adult or subadult territorial owls were captured and uniquely colorbanded.
Here, we provide summary information on areas surveyed, survey results, and reproductive
success of individual territories. Specific information on documented owl locations, including
colorband combinations of banded owls, will be provided to relevant management agencies
separately. In the near future, we will use data on capture histories of colorbanded owls to: (1)
estimate capture probabilities for territorial owls on the quadrats; (2) use these probabilities to
adjust direct counts of owls on the quadrats for owls we failed to detect; (3) estimate owl density
on the quadrats, as well as spatial variation in density; and (4) use this information to estimate
sample-sizes (numbers of quadrats) necessary to estimate owl abundance with specified
precision. This information can then be used in conjunction with cost estimates per quadrat and
information on project logistics to: (1) estimate overall costs for a long-term monitoring
program; and (2) develop recommendations for designing and implementing a long-term
population monitoring program for the Mexican spotted owl.
PROJECT PERSONNEL
Scientific Advisors: Gary C. White, Department of Fishery and Wildlife, Colorado State University; Alan B. Franklin, Cooperative Fish and Wildlife Research Unit, Colorado State University; James P. Ward, Jr. and Rudy M. King, Rocky Mountain Research Station.
Flagstaff office: Joe Ganey, Theresa Garito, Kerry Nodal
Fearless Field Crews (by duty station):
Flagstaff: Curt Kessler- crew leader, Douglas April, Rodney Davis. Tim Holt , Amie Membery,
Beverly Millay, Jamie Moser, Adam Stein, Adam Winters
Heber: Elliott Swarthout- crew leader, Margaret Adam, Christopher Dodge, Michael Holley,
Shawnacey Meares, Adam Ringia, Angelina Trombley, Ryan Wagner
Luna: Steven Ackers- crew leader, Brian Coyle, Julie Cummings, Rebecca Hunt, Matthew
McCarty, Tobias Shewan, Stefanie Schmitz, Paul Wenninger, Julie York
Payson: Peter Fonken- crew leader, Jesse Bennett, Gregg Dunn, Katrina Krause, Amy Lavoie,
Michael Lucid, Danielle McCallum, Elizabeth Vincent, Steven Vuturo
Quemado: Paula Shaklee- crew leader, Kirk Gilligan, Jennifer Gulbransen, Jamie Hagerty,
Heather McClure, Matt Schenk, Thomas Williams
Silver City: Jeff Jenness- crew leader, Steven Bird, Kevin Damm, Brian Gill, John Justus,
Michael Layes, Melissa Moyer, James Palmer, Jewel Trent
ACKNOWLEDGMENTS
The assistance of numerous people made this study possible. We would particularly like to
thank the Southwestern Region, U. S. Forest Service, for providing all funding for this project,
and the many forest district personnel who helped in innumerable ways. For logistical or other
support, we thank the following people (apologies to anyone we may have forgotten here):
Apache-Sitgreaves National Forest: Brian Dykstra, Heber Ranger District (RD); Vincente
Ordoez, Karen Stevens, and Tim Perren, Springerville RD
Arizona Game and Fish Department: Scientific Collecting Permits Office (especially Melissa
Kreighbaum)
Cibola National Forest: Dan Bastion, Magdalena RD
Coconino National Forest: Janie Agyagos, Sedona RD; Mary Ann Benoit, Long Valley RD;
Sandy Nagiller, Peaks RD; Cecelia Overby, Supervisors's Office (SO); Cathy Taylor, Blue Ridge
RD
Gila National Forest: Joe Anderson, Reserve RD; Paula Barnhill, Luna Work Center; Paul
Boucher, SO; John Baldwin, Joan Helen, Ed Holloway, Jerry Monzingo, and Scott Posner,
Glenwood RD; Pat Morrison, Quemado RD; Russell Ward, Mimbres RD
Kaibab National Forest: George Sheppard, Chalender RD
Northern Arizona University: Samantha Arundel, Department of Geography and Public
Planning
New Mexico Game and Fish Department: Greg Schmidt, Sandy Williams
Tonto National Forest: Cheryl Carrothers and Don Pollock, Payson RD
Regional Office, U. S. Forest Service: Jim Lloyd
Rocky Mountain Research Station: Bill Block, Allan Burnett, Jill Dwyer, Sandi Elefant, Karen
Gurley-Davis, Frank Lasorte, Sean Kyle, Deb Parker, Diane Prince, Brenda Strohmeyer, and
Brenda Whiteman, Flagstaff; Laura Bemis, Teri Pues, and John Toliver, Fort Collins
U.S. Fish and Wildlife Service: Sarah Rinkevich, Steve Spangle
INTRODUCTION
The Mexican spotted owl (scientific names for all organisms mentioned in this report are listed in Appendix 1) occurs in forested mountains and canyonland terrain throughout the southwestern United States and well into Mexico (Ward et al. 1995). This owl is associated with complex late-successional forests throughout much of this range (Ganey and Dick 1995). Because of concerns over the effect of timber harvest on amount and distribution of late-successional forest, the owl was listed as threatened in 1993 (Cully and Austin 1993). Shortly thereafter, a recovery team was appointed to assess the status of the owl and recommend management practices compatible with recovering the owl. The recovery plan produced by this team listed five criteria that must be satisfied in order to remove the owl from the list of threatened species, one of which dealt with monitoring population trends of this owl (Block et al. 1995:76-77). The USDA Forest Service, Southwestern Region (USFS), subsequently committed to implementing this population-monitoring program in an amendment to Land Management Plans in the Region (USDA 1996:88). This commitment was further formalized in a Biological Opinion issued by the U. S. Fish and Wildlife Service following consultation on the proposed Forest Plan amendments (USDI 1996:34). Subsequently, the USFS, Southwestern Region, provided funding to the Rocky Mountain Research Station and requested that the Station assist in implementing the population monitoring program.
As a first step in implementing this program, May et al. (1996) tested the proposed sampling methods on four study areas in Arizona. They concluded that the field methodology was workable, at least at the scale tested. The next step involved conducting a pilot study to further evaluate proposed methods for monitoring owl populations, especially the practicality of sampling at larger spatial scales, and to collect preliminary data on owl density, capture probabilities, and spatial variation in those parameters. These data would be used to estimate sample sizes and costs for conducting a long-term population monitoring program for the Mexican spotted owl.
This pilot study was conducted in 1999. This report provides a brief overview of the proposed
monitoring program, the pilot study, and summarizes some preliminary results from that pilot
study. Figures reported here are based on observational results, rather than on analysis of
capture-recapture data. These observational results are provided for the information of
management agencies cooperating with the pilot study. We caution that final estimates of owl
density and abundance will not be available until data analysis is completed, and will likely
differ from the observational estimates presented here.
OUTLINE OF THE PROPOSED MONITORING SCHEME
Briefly, the monitoring scheme proposed to estimate trends in owl abundance involves:
1. Surveying for owls on an unspecified number of sample quadrats approximately 40 - 75 km2in size, randomly scattered throughout selected portions of the owls range (see below);
2. Capturing and colorbanding owls so that individuals can be uniquely identified;
3. Estimating abundance of owls using capture-recapture models for closed populations, and analytical features contained in Program MARK (White and Burnham 1999);
4. Monitoring changes in abundance over time.
The objective of this monitoring scheme is to provide unbiased and precise estimates of trends in
owl abundance. Implementing this program required that a pilot study be conducted to allow
estimation of capture probabilities and the variance in owl density among quadrats. This
information could then be used to determine the number of quadrats required to obtain precise
estimates of owl abundance and population trend.
THE PILOT STUDY
Target Population
The target population identified for the long-term monitoring program was the population of territorial Mexican spotted owls in three Recovery Units (Upper Gila Mountains, Basin and Range-West, and Basin and Range-East; fig 1.; see Rinkevich et al. [1995] for discussion of Recovery Units). These Recovery Units were chosen because they include what are likely the core populations within the range of the Mexican spotted owl in the United States (Ward et al. 1995). The design focuses on territorial owls because no techniques are available to locate nonterritorial owls; hence, the number of nonterritorial owls cannot be estimated reliably.
The target population for the pilot study was the population of territorial owls in the Upper Gila
Mountains Recovery Unit, outside of the White Mountain and San Carlos Apache Reservations.
Sampling was restricted to one Recovery Unit to eliminate the potential contribution of
differences among Recovery Units to total sampling variance. The Upper Gila Mountains
Recovery Unit was chosen for the pilot study because it harbors a large population of Mexican
spotted owls (Ward et al. 1995) and because of its proximity to Flagstaff, which served as
headquarters for the pilot study. Tribal lands, which comprised about 18% of the recovery unit,
were excluded from the pilot study because access to these lands was not essential to accomplish
the pilot study.
Study Area
The Upper Gila Mountains Recovery Unit, approximately 84,250 km2 in area, corresponds
loosely to Bailey's (1980) Upper Gila Mountains Forest Province and William's (1986)
Datil-Mogollon Section. This area is transitional between the canyonlands of the Colorado
Plateau province to the north and the Basin and Range Province to the south. It is characterized
by steep mountains and entrenched river drainages dissecting high plateaus. For further
information on vegetation patterns, land uses, and other features of this area, see Rinkevich et al.
(1995). Descriptions of individual study areas follow below.
Methods
Study Area Selection. Sampling units for the pilot study consisted of randomly-located quadrats (fig. 2) approximately 40 76 km2 (15-30 mi2) in size. Quadrat size represented a compromise between the desire to replicate spatially and to estimate density accurately and precisely. Franklin et al (1990) examined density-area relationships for northern spotted owls in northwestern California, and concluded that density estimates stabilized at a study area size of 90 - 130 km2. This is larger than our proposed quadrat size, but there are mitigating circumstances. First, Franklin et al. (1990) did not use ecological boundaries in subsampling their study area, and as a result edge effects may have been exaggerated in their analysis. Second, visual inspection of their figure 4 ( a plot of the first derivative of change in density versus study-area size) indicates that the rate of change in density as study area size increases approached zero above 50 km2. Consequently, we believe that our quadrat size should be both large enough to reduce "edge effects" and small enough to allow spatial replication.
The sampling frame for quadrat selection was developed in cooperation with Dr. Samantha Arundel (Department of Geography, Northern Arizona University), using spatial modeling in a geographical information systems (GIS) environment. This effort involved first developing a GIS coverage that broke the entire Recovery Unit into separate quadrats in the approximate size range noted above, using size and shape constraints, topography (1:250,000 digital elevation models), and other spatial information. To the extent possible, quadrat boundaries were based on ecological boundaries such as ridgelines and watersheds. This was an attempt to reduce edge effects and minimize the probability that a quadrat boundary ran through an owls' activity center. Mapping of all quadrats is not only appropriate before selecting sample quadrats for the pilot study, but is essential if a design where quadrats are rotated into and out of the sample in subsequent years is employed in the long-term monitoring effort (Block et al. 1995: 108). Such a sampling design would guard against the possibility that land managers, consciously or unconsciously, might avoid active management in sample quadrats.
Once all quadrats were mapped throughout the Recovery Unit, 30 quadrats were randomly selected. The objective of this random sampling procedure was to produce an unbiased, representative sample so that inferences about owl abundance could be extended to the entire Recovery Unit, rather than being restricted to the sample quadrats. Four quadrats were subsequently dropped because sampling these areas would have created conflicts with other ongoing studies of Mexican spotted owls. A fifth quadrat was dropped because it contained a large proportion of private property, which effectively limited our ability to survey the area. Consequently, we sampled 25 quadrats.
Plot selection was stratified by 2 categories based on elevation, in an attempt to reduce variation
in observed owl density. Quadrats with 33% of their area occurring at elevations 6500 ft (1982
m) were placed in a "high-elevation" stratum, with all other quadrats placed in a "low-elevation"
stratum. Twenty and five quadrats were selected from high- and low-elevation strata,
respectively. The reduced emphasis on sampling quadrats from the lower stratum was based on
the expectation that few owls would be found in such quadrats, and therefore that spatial
variation in owl density would be low in that stratum. Conversely, greater variation was
expected in the high-elevation stratum, resulting in a need for greater sampling intensity.
Sampling Within Quadrats
Survey Routes. Field sampling followed methods established for studies of spotted owl demography (Franklin et al. 1996), with some differences. Survey routes and calling stations were established to ensure that the entire area within the quadrat was surveyed effectively. Generally, this meant that calling stations were established at intervals of 0.8 km (0.5 mi) along roads, trails, ridge tops, or drainage bottoms, depending on terrain. In some cases, calling stations were established on prominent vistas, saddles, or other special locations to facilitate complete coverage of the area. Establishment of calling routes and stations was guided by crew leaders experienced in conducting spotted owl surveys.
Owl Surveys. Night time calling surveys (Forsman 1983, Franklin et al. 1996) were conducted using established calling routes and points covering the entire quadrat area. Night time surveys were intended to locate general areas occupied by owls. We spent 10 min at each call point, alternately calling and listening for a response from territorial owls.
We attempted to complete four survey passes through the quadrats, except for quadrats where no owls were located by the end of the third survey pass. In those cases we did not conduct a fourth survey pass. A survey pass was considered completed when all calling stations were surveyed and all required daytime follow-up surveys were completed. Daytime follow-up surveys were used wherever an owl was detected during night time surveys. Daytime follow-up surveys were intended to: (1) locate nest and/or roost areas; (2) capture and mark owls; (3) resight previously-marked owls; or (4) determine the reproductive status of resident owls. Two follow-up surveys were allowed per response per pass through the quadrat.
Capture and Banding. Crews attempted to capture and individually mark all adult and subadult owls observed on the quadrat. We occasionally attempted to capture juveniles observed out of the nest, but this was not a priority. Owls were captured using noose poles and board traps (Forsman 1983, Johnson and Reynolds 1998). All adult and subadult owls captured were marked with a numbered locking aluminum band and a unique color-band on the other leg (as described in Forsman et al. [1996]). Juvenile owls captured were marked with a U. S. Fish and Wildlife Service band on one leg, but, with a few exceptions, were not color-banded.
After an initial physical capture, owls were considered to be "recaptured" on subsequent passes if we were able to resight colored leg bands. Banding records were not reviewed before resighting attempts, to avoid potential bias in recognizing color combinations. (Color combinations will be provided to the administrative units on which owls were banded for future reference.)
Data Summary: Territory and Occupancy Status. No formal data analyses are included in
this report. Rather, we report here some simple summaries of quadrats surveyed, numbers of
owls banded, and numbers of territories confirmed or suspected on various quadrats. This
information is intended primarily for use by land-management agencies. Again, formal analysis
of mark-recapture data will be required before we can develop rigorous estimates of owl
abundance. This analysis is ongoing.
Territory Status. We classified a territory as confirmed if any of the following scenarios occurred:
a) a nesting pair or juveniles were located;
b) 1 owl was located roosting in the same area (roost locations within 400 m of each other) on two or more passes, with the first location before 15 August;
c) 1 owl was heard at night on two or more passes, and one day-time roost was located, with the first location before 15 August (again, locations within 400 m of each other);
d) 1 owl was heard at night on at least 3 passes, with the first location being before 15 August
(locations within 400 m of each other).
We classified a territory as suspected if any of the following scenarios occurred:
a) 1 owl was located roosting in the same area (within 400 meters) on two or more passes, with the first location being after 15 August;
b) 1 owl was heard at night in the same area (locations within 400 m of each other) on two or more passes and one day-time roost was located, with the first location being after 15 August;
c) an owl of the same sex was heard in the same area (locations within 400 m) on at least 2
passes, with the first location being before 15 August.
We did not consider single or scattered observations that did not meet the above criteria to
constitute sufficient evidence that an occupied territory existed.
Occupancy Status. We classified a territory as occupied by a pair if any of the following circumstances occurred:
a) a female was observed on a nest;
b) a male was observed delivering a mouse to a nest;
c) a male delivered a mouse to a female;
d) a male or female was observed attending young;
e) 1 unattended young were located (prior to 15 Aug);
f) a male and female were heard or observed within 400 meters of each other on 1 day-time
surveys;
g) a male and female were heard or observed within 400 meters of each other on 2 night-time
surveys.
All other observations were classified as pair status unknown. Some of these sites were likely
occupied by single birds, but typically we were unable to relocate and observe single owls
enough times to state with confidence that a second owl was not present.
RESULTS
We established 2,345 calling points across the 25 sample quadrats. The required number of survey passes was completed on 21 of the 25 quadrats (Table 1). Of the remaining 3 quadrats, 3 survey passes were completed on 1, a third pass was largely completed on a second, and 2 passes were completed on a third. On the fourth quadrat, four passes were completed on the southern half, whereas only two passes were completed on the northern half, where no owls were located during these two passes. These areas were not completed for a number of reasons, but primarily because of difficult terrain and access.
Total survey effort involved calling 8,257 points (including repeat visits) over the course of all passes (Table 2). This resulted in 434 nocturnal detections of owls, which triggered 400 daytime followups. One or more owls were located on 202 of these followups, and 57 territorial adult and subadult owls were captured and colorbanded (Table 3). In addition, 64 juvenile owls were located and 23 of these juveniles owls were banded (Table 4). See area reports (below; also see Tables 3 and 4) for further information on numbers of territories resolved, reproductive histories, and numbers of owls banded by quadrat.
Spotted owls were heard or seen on 18 quadrats, 16 (80%) in the high-elevation stratum and 2
(40%) in the low elevation stratum. Of these, we suspect that 14 quadrats in the high-elevation
stratum and 1 in the low-elevation stratum actually supported resident owls whose activity center
was located within the quadrat boundary (70 and 20% of total quadrats within strata,
respectively).
Quadrat Summaries
The following narratives are intended as brief summaries of project activities and results, for the
benefit of relevant management agencies. They are not intended as exhaustive descriptions of
quadrats, nor are they intended to summarize all instances when and where owls were located;
specific location data will be provided directly to agencies with jurisdiction over particular
quadrats. In developing these summaries and reporting results, we have consciously avoided
assigning names to owl territories, believing that to be the prerogative of the affected Ranger
Districts. In a few cases we have used names provided by the districts for historically-occupied
territories. For convenience, we did name quadrats, as well as assigning each a unique number.
L or H in quadrat designations refers to whether it fell within the low- or high-elevation stratum,
respectively.
Apache-Sitgreaves National Forest
We surveyed four quadrats on this forest. An additional four quadrats were surveyed on lands
officially designated as Apache National Forest, but administered by the Gila National Forest.
These are discussed under Gila National Forest.
Chevelon (H08): This quadrat was located on the Chevelon Ranger District in Coconino County, approximately 23 miles west of Heber, Arizona. Elevation ranged from approximately 2075-2320 m (6800-7600 ft) on the quadrat. The dominant feature on this quadrat was north-flowing Willow Creek and the side canyons of Gentry, Bear, and Hart. These steep, narrow canyons contained mixed-conifer forests as well as ponderosa pine forest. The uplands between these canyons were generally gently sloping and contained mixed-conifer forest in the south, grading into ponderosa pine forest in the central and northern portions of the quadrat.
We completed four survey passes in this quadrat and located two nesting pairs of owls. Both
pairs fledged three young. Both nesting areas occurred in unlogged mixed-conifer forest.
Territory 1 (Hart Canyon) was occupied by an adult male and female. We banded the female,
but not the male. The nest and main activity center of the owls occurred just north of the
boundary of the quadrat, although on several occasions the owls were heard within the quadrat.
Territory 2 (Mule Crossing) was also occupied by an adult male and female and occurred
entirely within the quadrat. Here, we banded the male but not the female. No juveniles were
banded on this quadrat.
Heber (H09): This quadrat was located on the Heber Ranger District in Navajo County, approximately 5 miles south of Heber, Arizona. Elevation ranged from approximately 1980-2210 m (6500-7250 ft) on the quadrat. The most dominant feature of this quadrat was the north-flowing Black Canyon and several shallow, wide side drainages, all north of Black Canyon Lake. The southern portion of the quadrat was composed mostly of ponderosa pine forest with a few scattered white firs on north facing slopes. The north end of the quadrat was transitional between ponderosa pine forest and pinyon-juniper woodland.
We completed three survey passes on this quadrat without locating any spotted owls.
Springerville (H13): This quadrat was located on the Springerville Ranger District, Apache County, approximately 7 miles south of Springerville, Arizona. Elevation ranged from approximately 2290-2960 m (7500-9700 ft) on the quadrat. This quadrat centered around Milligan Creek and its side drainages. The southern portion of the quadrat was dominated by large grassy parks devoid of trees. Mixed-conifer forest occurred in areas of steep topography and in the bottom of drainages dissecting these uplands. The central portion of the quadrat was dominated by ponderosa pine forest and the northern and eastern portions of the quadrat were primarily pinyon-juniper woodland.
We completed four survey passes of this quadrat. We located one nesting pair of owls in Benton
Creek. This territory was occupied by an adult female and a subadult male, and fledged one
young. We were not able to capture either the female or male and did not band the juvenile.
The nesting area was located in unlogged mixed-conifer forest.
Rose Peak (H20): This quadrat was located on the Clifton Ranger District, Greenlee County, approximately 15 miles south of Hannagan Meadow, Arizona. Elevation ranged from approximately 1680-2680 m (5500-8800 ft) on the quadrat. This quadrat included Rose Peak in the northeast corner of the quadrat and the western watershed of Rose Peak (Pine and Hogtrail Canyons). The area was mostly roadless, and was characterized by steep slopes and deep drainages. The ridgetops and upper portions of many slopes were covered in pinyon-juniper woodland and interior chaparral. The drainage bottoms and heads of major canyons had stands of ponderosa pine and Gambel oak (especially on the west side of Rose Peak). The southeastern portion of the quadrat ranged from pinyon-juniper woodland to open grassland, with the drainage bottoms composed of Fremont cottonwood and Arizona black walnut.
We completed four survey passes of this quadrat. We located one suspected territory and
banded a male of unknown age (his tail feathers were regrowing and still in the sheath at the
time of capture) in unlogged ponderosa pine - Gambel oak forest near the summit of Rose Peak.
We classified this territory as suspected because we never found a day-time roost (the male was
captured at night) and detected the male on only two survey passes. No female was heard or
seen. While conducting surveys, we also repeatedly heard a pair of owls in Strayhorse Canyon,
approximately 1 km (0.6 mi) outside the quadrat boundary, and also heard a single male calling
in Hot Air Canyon well outside the quadrat boundary.
Cibola National Forest (1 quadrat)
Datil (H11): This quadrat was located in the Datil Mountains on the Magdalena Ranger District, 8 miles northwest of Datil, Catron County, New Mexico. It covered the upper portion of Thompson Canyon and Z Slash Draw, and the lower portions of Davenport and Hay Canyons. Elevation ranged from approximately 2380-2850 m (7800-9350 ft) on the quadrat. The west side of the quadrat was characterized by open pinyon-juniper woodland on gentle, rolling terrain. The east side was characterized by steep hills, with a mix of dense pinyon-juniper woodlands on south-facing slopes and ridges and ponderosa pine forest on north-facing slopes and in the drainages. There were pockets of residual mixed-conifer forest at the head of Thompson Canyon and up one of the side drainages in Davenport Canyon, but these were young stands with no residual old-growth component.
We completed three survey passes on this quadrat without locating any spotted owls.
Coconino National Forest (6 quadrats)
Red Mountain (H01): This quadrat was located around Red Mountain, Coconino County, Arizona. It straddled the boundary between the Coconino (Peaks Ranger District) and Kaibab (Chalender Ranger District) National Forests. Terrain was generally flat with Red Mountain rising in one corner. Red Mountain was a cinder cone with one side heavily eroded providing many holes and small caves. Elevation ranged from approximately 1950-2430 m (6400-7965 ft). Habitat was predominantly pinyon-juniper woodland with some ponderosa pine forest found on and in the vicinity of Red Mountain.
We completed three survey passes on this quadrat without locating any spotted owls.
Peaks (H02): This quadrat was located on the Peaks Ranger District, Coconino County, Arizona. Approximately 50% of the quadrat fell within the Kachina Peaks Wilderness Area on the San Francisco Peaks. Terrain was generally steep mountain slopes with broad ravines. Elevation varied from approximately 2260-3660 m (7400-12,000 ft). Habitats included ponderosa pine forest, mixed-conifer forest, spruce-fir forest, quaking aspen, and alpine tundra.
We completed four survey passes and located three pairs of spotted owls on this quadrat. Two
of these pairs were nesting and produced two fledglings each. Both nests were located in large
old-growth Douglas-fir trees in mixed-conifer forest. One of the nest trees was immediately
adjacent to a heavily-used hiking and biking trail in the Lamar Haines wildlife area. The nest
was actually visible from the trail if you knew where to look. We banded 5 of the 6 territorial
owls located on this quadrat. The sixth had been banded previously by another investigator. No
juveniles were banded.
Wing Mountain (H03): This quadrat centered around Wing Mountain, Peaks Ranger District, Coconino County, Arizona. It stretched from I-40 in the south to the Hart Prairie area in the north. Terrain was dominated by small hills and valleys. Elevation ranged from approximately 2165-2615 m (7100-8578 ft). The area was dominated by ponderosa pine forest (generally about 50 100 years old) with a small area of mixed-conifer forest on the north side of Wing Mountain.
We completed three surveys passes without locating any spotted owls on this quadrat.
General Springs (H07): This quadrat was located on the Blue Ridge Ranger District, Coconino County, Arizona. It included the majority of several major canyons that flow north from the Mogollon Rim to East Clear Creek. These included General Springs Canyon, Bear Canyon, Houston Draw, and small portions of Crackerbox Canyon and Dick Hart Draw. The relatively flat uplands that separate these canyons were characterized by stands of ponderosa pine interspersed with pockets of Gambel oak and other deciduous trees. The canyons varied in their vegetation from open ponderosa pine forest in their southern, upper reaches to dense mixed-conifer forest in their deeper northern portions. The northern reaches of the canyons also had substantial rock cliffs and outcrops. Elevation ranged from approximately 2075-2320 m (6800-7600 ft) on the quadrat.
We completed four survey passes on this quadrat, and located two spotted owl territories within the quadrat and another three territories adjacent to the quadrat. In mid-June, a pair of owls with three fledged juveniles were located just north of the quadrat boundary near the confluence of General Springs and Bear Canyons. We captured and banded both adults. This family group was subsequently found to be using the adjacent areas of both General Springs and Bear Canyons both inside and outside the quadrat.
On 9 July both a male and female were detected farther up General Springs Canyon. On subsequent follow-ups on 13 July and 5 August a male was heard calling but could not be visually located (i.e. he stopped calling before observers located him). On 7 August another unknown-sex bird was heard in the same area. Subsequent follow-ups were unsuccessful. On 25 August an unknown-sex bird was seen in the area. A male was heard on subsequent follow-ups, but again could not be located. These repeated detections provide enough evidence to confirm that a territory exists in this portion of General Springs Canyon, but the occupancy status of this territory remains unclear.
A pair of owls also was located in Houston Draw, at the extreme northeast corner of the quadrat, on 7, 8, 9, and 22 August, and again on 5 and 6 September. We banded the female, but not the male. No juveniles were located, but a member of the Blue Ridge Ranger District owl crew reported having heard distinctive begging calls while working adjacent to Houston Draw outside the quadrat.
During the first three nocturnal survey passes multiple birds were detected in East Miller Canyon just west of the quadrat boundary. Early in the season, daytime follow-ups in this area repeatedly resulted in vocal responses and some brief visual observations, but no actual locations of roosting owls. On 8 August a pair was located in East Miller Canyon and the male was captured and banded. The female was not captured. No juveniles were observed with this pair. On 11 August three fledged juveniles and a male were located further north along East Miller Canyon. Two of the juveniles were captured and banded. The male and third juvenile were not captured, and the female associated with this family group was not located. Historic use patterns for this canyon have included two pairs in the general areas where the pair and family group were found (data on file, Blue Ridge Ranger Station).
This quadrat and its immediate surroundings clearly includes five occupied territories. What
continues to be unclear is owl usage in the remainder of the quadrat. This quadrat was
characterized by numerous other scattered nocturnal detections. In many cases, daytime
followups resulted in faint vocal responses, but the owls did not call long enough for us to locate
the roost. Additional monitoring and banding will be necessary to definitively determine the full
occupancy pattern of this quadrat.
Lake Montezuma (L01): This quadrat was located in the Beaver Creek Ranger District, Yavapai County, Arizona. It was located along Forest Road 618 from approximately the M-Diamond Ranch on the north to Forest Road 214 (Cedar Flats Rd) on the south. East to west it ranged from above to below the Mogollon Rim which ran through the area. Terrain was relatively flat below the rim, with a line of sandstone cliffs bisecting the area from north to south. The plateau above the rim was broken by steep canyons. Elevation ranged from approximately 1190-1830 m (3900-6000 ft). The plateau above the rim was dominated by pinyon-juniper woodland. Juniper mixed with agave, mesquite, and prickly pear dominated below the rim.
We completed three survey passes on this quadrat without locating any spotted owls.
Jack's Canyon (L02): This quadrat was located on the Blue Ridge Ranger District, Coconino County, Arizona. The quadrat centered around Jack's Canyon and included Chavez Draw, a significant drainage entering Jack's canyon from the northwest. It was characterized by a mixture of pinyon-juniper woodland, grassland, and ponderosa pine forest. Ponderosa pine forests were primarily limited to Jack's Canyon (south of Chavez Draw) or areas immediately adjacent. Areas of significant riparian vegetation, including large cottonwood trees, also occurred in Jacks Canyon, as did sizable stands of Gambel oak and other deciduous trees including walnut and box-elder. Jack's Canyon also featured rock faces of weathered limestone throughout its length. Elevation ranged from approximately 1800-2040 m (5900-6700 ft) on the quadrat.
We completed four survey passes on this quadrat. One pair of owls was located within the quadrat during nocturnal surveys on the second, third, and fourth passes. They were consistently located roosting in a side drainage on the west side of Jack's Canyon approximately 700 meters south of the quadrat boundary. Thus, it appears that this pair's activity center was located outside the quadrat but their use area extended well into the quadrat. The roost area was in a narrow side drainage with large ponderosa pines and dense Gambel oak bounded by sculpted rock faces. We banded the female but were unable to capture the male. This pair apparently did not nest, as no juveniles were observed.
On 13 June a possible pair of owls were seen in Jack's Canyon north of Chavez Draw. These owls were not seen clearly enough to determine species. Some vocalizations, but no four-note calls, were heard. Subsequent daytime follow-up visits located no owls, nor did we detect spotted owls in this area on any other passes.
Beginning in early August the southern portion of this quadrat was affected by the
lightning-caused Turkey Fire that burned from a large mesa northwest of the canyon down
through the canyon, and up the side drainages on its' eastern side. The side canyon used by
roosting spotted owls (see above) was unaffected by fire, even though the surrounding area
experienced some of the hottest burn.
Gila National Forest (10 quadrats, including Apache National Forest lands administered by
the Gila)
Slaughter Mesa (H12): This quadrat was located in the Gallo Mountains on the Quemado Ranger District, 17 miles south of Quemado, Catron County, New Mexico. It included the top of Slaughter Mesa dissected by Largo, Sawmill and Porcupine Canyons. The mesa top consisted of a mixture of open grassland with patches of ponderosa pine forest. Largo Canyon was a narrow, steep-sided drainage with open ponderosa pine forest and pinyon-juniper woodland on the east-facing slope and mixed-conifer forest with islands of ponderosa pine on the west-facing slope. Sawmill Canyon was a wide canyon with open ponderosa pine habitat over most of the canyon. The headwaters of Sawmill Canyon contained a small pocket of old-growth mixed-conifer forest. Porcupine Canyon had young to mature mixed-conifer forest on the west-facing slope with ponderosa pine forest on the east-facing slope. Elevation ranged from approximately 2380-2685 m (7800-8800 ft) on the quadrat.
We completed four survey passes in this quadrat, and located one nesting pair in unlogged mixed-conifer forest in Largo Canyon. We were unable to locate the exact nest tree on the first pass but had it pinned down to a group of four Douglas-firs that all had severe mistletoe infestations. By the second pass three juveniles had already fledged. We were unable to capture the adults but banded all three juveniles.
We also had scattered responses from other portions of this quadrat which were difficult to
interpret. Most of these responses occurred after surveying was completed and the surveyors
were walking back towards their truck, suggesting that they may have represented an owl who
was flying in from a distance before responding. If this owl does reside within the quadrat, it is
likely that his activity center is in Porcupine Canyon. Based upon these responses, we classified
this area as a suspected territory.
Mangas Mountain, H14: This quadrat was located in the Mangas Mountains on the Quemado Ranger District, 21 miles south-southeast of Quemado, Catron County, New Mexico. This quadrat covered the headwaters of Patterson Canyon, including Caballeriza Canyon, Ladies Canyon, Gallina Canyon and Landing Camp Canyon. It also covered San Antone Canyon and Burro Spring. The area was characterized by many moderate-sized canyons with numerous side drainages. This quadrat was heavily roaded and the habitat was mostly cut-over ponderosa pine forest. There was some mixed-conifer forest in Trail Canyon just north of the quadrat boundary. Elevation ranged from approximately 2225-2960 m (7300-9700 ft) on the quadrat.
We surveyed this quadrat four times, and heard owls in several areas. A male was heard at the north end of the quadrat on 12 June. A male assumed to be this bird was found on the follow-ups outside the quadrat in Trail Canyon. He was caught and banded on the second follow-up of the first pass, was detected on all four survey passes, and was seen on the follow-ups for the first three passes, with all daytime locations in Trail Canyon. We never located him with or heard a female in the area.
On 7 August an unknown-sex owl was heard from 2 call points in San Antone Canyon. Later that night, both a male and female owl were heard on the ridge between San Antone Canyon and Burro Spring. Still later an unknown-sex owl was heard calling just down the ridge from the earlier pair response. Follow-ups were unsuccessful in both drainages. We suspect that these responses represent a single pair moving about. This area consists of low ridges and open pine stands and sound carries very well. The birds were not detected until 2236, and may have flown into the area from outside of the quadrat.
On 12 June, during the first survey pass, a male was heard near the mouth of Caballeriza Canyon. We were not able to locate this owl during follow-up surveys, and it was never heard again. The habitat in this area is all open pine forest and grassland. Because there does not appear to be any suitable habitat in the area, and because this owl was never heard on subsequent passes, we suspect that it is not a resident bird.
Summarizing, this quadrat did not contain any confirmed or suspected territories within its
boundaries. The activity center for the Trail Canyon male fell outside the quadrat boundary.
The pair response at San Antone Canyon did not meet our requirements for a territory, as all
responses occurred on a single night.
Brushy Mountain (H16): This quadrat centered around the Upper Pueblo Creek watershed north of Pueblo Park, Glenwood Ranger District, Catron County, New Mexico. The quadrat ranged in elevation from approximately 1868-2683 m (6127-8800 ft). The vegetation was predominantly ponderosa pine/Gambel oak forest or pinyon pine/juniper associations although mixed-conifer forest occurred on many of the north-facing slopes and in drainages above approximately 2287 m (7500 ft). Most of the quadrat was roadless. The backcountry was accessed from forest roads 232, 209, and 209B and from trails 90, 21, 36, and 515.
Only 3 survey passes were completed on this quadrat due to time constraints. Four spotted owl territories were confirmed within the quadrat and an additional territory (not included in table 3) was suspected in Johnson Canyon west of the quadrat boundary. Four male and three female spotted owls were banded at or near their nest locations. A total of nine juveniles were located among the four territories.
Territory 1 was located west of the West Fork of Pueblo Creek. An adult male and an adult female spotted owl were banded on 26 July, and two juveniles also were observed on this date. The suspected nest location was in a cavity in a 6-8 m (20-25 ft) cliff surrounded by a dense stand of young Gambel oaks and small (<40 cm [16 in] diameter at breast height [dbh]) ponderosa pines at 2207 m (7240 ft) elevation.
Territory 2 was located on the north-facing slopes of Camp Canyon. A pair of adult spotted owls were banded near the suspected nest location on 28 June, and three juveniles were observed as well. The suspected nest location was in a transition area between ponderosa pine/Gambel oak and mixed-conifer forest at approximately 2195 m (7200 ft) elevation.
Territory 3 was located immediately west of the Flying T Spring trailhead. A second-year subadult male was banded on 29 June. We also observed a second-year subadult female and 2 juveniles on that date, but were unable to capture the female. The suspected nest location was in a steep, rocky drainage surrounded by mixed-conifer vegetation at approximately 2378 m (7800 ft) elevation. On 27 July, this pair was heard interacting with another pair of spotted owls on the west side of FR 209 near the quadrat boundary. The second pair probably originated from Johnson Canyon west of the quadrat, where spotted owls were heard on several occasions.
The fourth territory was located near the top of the Pueblo Creek watershed approximately 1 km
(1.6 mi) south of Aspen Mountain. A pair of adult spotted owls were banded near the suspected
nest location on 30 June. Two juvenile owls were observed with this pair. The suspected nest
location was in a mixed-conifer stand consisting of large (61 cm [24 in] dbh) Douglas firs and
southwestern white pines at approximately 2378 m (7800 ft) elevation.
Telephone Canyon, H17: This quadrat was located in the Tularosa Mountains on the Reserve Ranger District, 12 miles southeast of Reserve, Catron County, New Mexico. The quadrat covered Telephone Canyon, Elk Horn Canyon, the upper portions of Eckleberger Canyon and the middle portion of North Fork Negrito Creek (from the junction of Elk Horn Canyon upstream to Collins Park). The area was a mixture of habitat types ranging from grassland to mixed-conifer forest. The Eckleberger Canyon area had gentle slopes and open ponderosa pine woodland. The Negrito Creek drainage ranged from flat terrain with open grassland to steep slopes with pinyon-juniper woodland on the ridges and ponderosa pine stands in the creek bottoms. Elk Horn Canyon had relatively steep slopes with some pockets of young mixed-conifer forest, but consisted mostly of ponderosa pine forest and pine-oak woodland. Telephone Canyon had a mix of all habitat types and was the only area with mature mixed-conifer forest. Elevation ranged from approximately 2135-2620 m (7000-8600 ft) on the quadrat.
We surveyed this quadrat four times, and located a pair and 3 juveniles in unlogged
mixed-conifer forest in a side drainage of Telephone Canyon. All five owls were captured and
banded. This pair was located on all four passes, and appeared to use the whole upper portion of
Telephone Canyon from just south of Elk Horn Canyon to the headwaters of Telephone Canyon.
No other spotted owls were detected in this quadrat.
Pueblo Creek (H18): This quadrat encompassed the Pueblo Creek watershed south of Pueblo Park, including Pup Canyon, Bangtail Canyon, Tige Canyon, and Bear Canyon. The quadrat was located within the Blue Range Wilderness Area, Glenwood Ranger District, Catron County, New Mexico. Elevation ranged from approximately 1732-2560 m (5680-8400 ft). The vegetation varied greatly depending upon elevation, aspect, and proximity to major creeks. Uplands at lower elevations were dominated by juniper and desert scrub vegetation while the riparian areas at the lower elevations were primarily deciduous. Pinyon pine/juniper and Ponderosa pine/Gambel oak communities were the principal vegetation types at mid elevations, and mixed-conifer associations were present on the north-facing slopes and in the drainages above 2287 m (7500 ft). Mixed-conifer forest accounted for <25% of the area within the quadrat. Access into the back country was gained from trails 43, 91, 54, and 23.
Due to time constraints, only two survey passes were completed on this quadrat. Three spotted owl territories were confirmed in the general area, although the activity center of one territory may lie outside the quadrat boundary. In addition, single owls were seen in two other areas (see below). We banded two adult males, an adult female, a subadult male, and a subadult female on this quadrat, and located three juveniles.
Territory 1 was located in the uppermost portion of Bear Canyon. A second-year subadult female was banded here on 22 July, and an adult male was banded in the same location on 10 August. Reproductive status was not determined for this pair. The banding location was in mixed-conifer habitat in a north-facing tributary of Bear Canyon at approximately 2317 m (7600 ft) elevation.
Territory 2 was located immediately southwest of territory 1, over the ridge at the top of Yam Canyon. An adult male was banded here on 15 August, and a female and two juveniles were also observed at that time. The owls were located in mixed-conifer habitat in a northwest-facing drainage at 2378 m (7800 ft) elevation.
Territory 3 was located approximately 0.5 km (0.3 mi) north of Tige Spring. An adult female was banded here on 23 August. A male of unknown age and a juvenile had been previously seen in the company of a female approximately 50 - 60 m from the banding location. This location was in mixed-conifer habitat in a north-facing drainage at 2195 m (7200 ft) elevation.
A second-year subadult male was banded approximately 1 km (0.6 mi) northwest of territory 3 near the top of Tige Canyon. No other owls were observed with this bird nor were there any previous or subsequent observations of owls in this area. As a result, it is not known if this was the male observed with the female and juveniles from territory three. The habitat in this area also was mixed-conifer on a north-facing slope at approximately 2317 m (7600 ft).
An additional spotted owl of unknown sex and age class was observed on 25 May in a tributary
canyon of Pueblo Creek while call stations were being located during the day. The owl was seen
as it flushed from a pothole in a cliff in a box canyon containing pine-oak forest, at
approximately 1890 m (6200 ft). We never heard or saw spotted owls in this area again.
Pitchfork Canyon, H19: This quadrat was located in the Elk Mountains on the Reserve Ranger District, 23 miles southeast of Reserve, Catron County, New Mexico. It covered portions of Pitchfork Canyon, the upper portion of T Bar Canyon and the upper portion of Canyon Creek. The southern end of this quadrat was open grassland with gentle rolling terrain, whereas the northern end was primarily open ponderosa pine forest with south-facing drainages. The slopes were moderate and most of the area had been logged within the last 20 years. Elevation ranged from approximately 2360-2620 m (7750-8600 ft) on the quadrat.
We surveyed this area four times. We heard a male owl twice, on passes 1 and 3, in two
separate areas. The owl on pass one originally responded from within the quadrat, then moved
past the observer and out of the quadrat, still hooting. We were unable to relocate this owl on
daytime follow-up surveys. The response on pass 3 came from outside of the quadrat. The owl
took 9 minutes to respond and answered from a distant ridge. Because the response came from
well outside the quadrat, no follow-up was done. No spotted owls were detected on either the
second or fourth survey passes, and we suspect that this quadrat contains no resident spotted
owls.
Whitewater Creek (H21): This quadrat encompassed the upper Whitewater Creek watershed, Gila Wilderness Area, Glenwood Ranger District, Catron County, New Mexico. Elevation ranged from approximately 1900-3320 m (6240-10,895 ft). The quadrat was dominated by mixed-conifer forest, with ponderosa pine stands in the south-facing side drainages of the main canyon below approximately 2285 m (7500 ft). The coniferous forest was nearly contiguous throughout much of the quadrat, except for a large aspen stand on the southwest flank of Willow Mountain and chaparral vegetation on the south-facing slopes of the main drainage below 2285 m. Access into the backcountry was gained from trails 179, 181, 182, 206, 207, 212, and 213.
Two complete survey passes and most of a third pass were completed on this quadrat. Nine spotted owl territories were confirmed and at least two additional territories were suspected within the quadrat. Four adult males and four adult females were banded at or near their nest locations. Seven juvenile spotted owls were located and one was banded.
Territory 1 was suspected in the South Fork of Whitewater Creek in the southwestern corner of the quadrat. This area was dominated by thick mixed-conifer forest on a 100 - 150 m flood plain surrounding the South Fork of Whitewater Creek. Upland areas were less dense but were also characterized by mixed-conifer forest. Elevation was approximately 2320 m (7600 ft). Inadequate data were obtained to confirm the occupancy of this territory. Initial observations consisted of two nocturnal detections of a pair of spotted owls near the confluence of the South and East Forks of Whitewater Creek, and of a single spotted owl of unknown sex approximately 1 km (0.6 mi) up the East Fork. Follow-up visits were unsuccessful in locating a nest or roosting pair. Two nocturnal detections of a single spotted owl and a day time roost location of a pair were obtained during the second pass 1 km (0.6 mi) up the South Fork Pack Trail approximately 1.6 km (0.8 mi) southeast of the original observations. Based on the spatial pattern of occupancy elsewhere in this quadrat, we suspect that there could be as many as three territories in the South and East Fork drainages.
Territory 2 was located in Winn Canyon. The suspected nest location was in a cave in a large rock outcrop on a ridgetop. The male was located perched at the mouth of this cave during two daytime follow-ups in June, and the female was heard from inside the cave on both occasions. Unfortunately, we were unable to return for additional daytime followups until 19 August. At this time we banded an adult male, but were unable to locate the female or any juveniles.
Territory 3 was located along the Deloche trail (179) approximately 1 km (0.6 mi) north of Whitewater Creek. The nest was located in a witch's broom in a small (dbh < 46 cm [18 in]) Douglas fir on a steep south-facing slope at approximately 2256 m (7400 ft). Both adults were banded on 25 June near the nest location. A single juvenile was observed on 4 August.
Territory 4 was located approximately 1 mile northeast of Grouse mountain near Whitewater Creek. A suspected nest was located in a cavity at the broken top of a large (dbh >61 cm [24 in]) Douglas fir over-topped by a large lateral branch. The habitat was characterized by mixed-conifer and ponderosa pine forest at approximately 2440 m (8000 ft). elevation. A pair of adult spotted owls were banded and three juveniles were observed near the nest site on 24 June.
Territory 5 was located approximately 1.5 miles north of Grouse Mountain near Whitewater Creek. The habitat is characterized by mixed-conifer vegetation in extremely steep drainages on both the north- and south-facing slopes adjacent to Whitewater Creek. This territory was confirmed based on numerous nocturnal detections only; daytime follow-ups did not locate a pair or any juveniles. As a result, as many as two territories may be present in this area.
Territory 6 was located along the Redstone Trail (206) approximately 1 km (0.8 mi) west of Willow Mountain. A pair was detected here at night on 27 May. A second-year subadult female was banded at dusk and a male spotted owl of unknown age class also was observed on 22 June. On 23 June both owls were located in a cave near the capture site. The female would not leave the cave, suggesting the possibility that she may have had young in the cave, but we were unable to confirm this. The habitat in this territory was characterized by a younger and more open mixed-conifer stand than that observed in the territories closer to Whitewater Creek. The elevation was approximately 2685 m (8800 ft).
Territory 7 was located at the confluence of Lipsey Canyon and Whitewater creek. The habitat was characterized by dense mixed-conifer adjacent to Whitewater Creek and an open mature ponderosa pine stand on the uplands surrounding the Redstone Trail (206). Two nocturnal detections during pass 2 and seven during pass 3 were obtained within a 400 m radius. On 3 September, an adult male and a female of unknown age class were located roosting within 150 m of each other at an elevation of approximately 2350 m (7700 ft). Neither bird was banded and no juveniles were detected.
Territory 8 was located on the north-facing slope above Redstone Park. A pair and 2 juveniles were located near the suspected nest location and the adult female was banded on 9 June. The adult male was banded on 23 June and one of the juveniles was banded on 12 July in the same area. The suspected nest location was in dense, mature to old-growth mixed-conifer with densely vegetated drainages at approximately 2470 m (8100 ft). This area was located <100 m from the lightning-caused Winn fire, which burned in May 1999.
Territory 9 was located near the top of the Whitewater Creek drainage approximately 1 km (0.8 mi) west of Whitewater Baldy. At least one nocturnal detection was obtained within a 400 m radius during all three passes. In addition, two spotted owls were seen roosting together on 14 and 23 June. The roost locations were in mixed-conifer vegetation at approximately 2835 and 2930 m (9300 and 9600 ft) on the southwestern slope of Whitewater Baldy. No juveniles were located and neither bird was banded.
Territory 10 was located in a large side drainage northeast of Black Mountain and northwest of Center Baldy. The habitat was dense closed-canopy mixed-conifer in a steep canyon with a thick understory in the drainages. Both a male and a female were heard during nocturnal surveys on 2 and 22 August. In addition, a female of unknown age class and a juvenile were observed roosting together on 3 August. The elevation at the roost site was approximately 2835 m (9300 ft). No birds were banded in this territory.
An eleventh territory was suspected to be occupied by a single male spotted owl near the top of the Redstone Trail (206) approximately 2 km (1.2 mi) northwest of Willow Mountain, in a mixed-conifer drainage at an elevation of 2650 m (8700 ft). Nocturnal responses were obtained on the first and second passes well within the 400-m radius limit and a single male spotted owl was located roosting during a daytime visit. This bird escaped during a capture attempt and was never relocated during the day.
Surveying this quadrat was difficult because of the extremely steep terrain and large cliffs and
outcrops, as well as the large number of nocturnal responses requiring followups. Considerable
additional effort would be required to be confident that all owls were located in this area. An
interesting feature of this quadrat was that most nest and many roost areas were located well up
the slopes out of the main drainages, in contrast to the pattern seen in many other areas.
Gila Cliff Dwellings (H22): This quadrat was located approximately 45 miles north of Silver City, in Catron and Grant Counties, New Mexico. The entire quadrat was within the Gila Wilderness, with the closest access point 4 miles to the east at the Gila Cliff Dwellings National Monument. The quadrat covered approximately 5,600 ha (21.7 mi2) and ranged from 2000 - 2720 m (6400 - 8700 ft) in elevation. Vegetation consisted primarily of ponderosa pine forest, with occasional patches of pinyon-juniper woodland in the lower elevations and on the south-facing slopes and mixed-conifer forest in the higher elevations. Riparian vegetation occurred throughout the Little Creek drainage, which flows through the length of the quadrat. Slopes were generally fairly gentle throughout the quadrat, with steep portions around the Granite Peak area.
We completed four passes on this quadrat and located 4 confirmed territories. Three of these produced a total of 5 juveniles, and we banded four adults or subadult and four juveniles on these territories. Occupancy by at least a female was confirmed on a fourth territory. A fifth territory was suspected in an area where a single owl of unknown sex was heard on 2 separate passes, but could not be located during the day.
Tadpole Ridge (H23): This quadrat was located approximately 20 miles north of Silver City, on the Silver City RD, in Grants County, New Mexico. The quadrat ran from approximately Tadpole Ridge, just west of NM Highway 15, north to a ridge approximately three miles north of Sapillo Creek, and included parts or all of Sheep Corral, Cow, and Spring canyons, and Trout and Sapillo creeks. It covered approximately 6,600 ha (25.5 mi2) and ranged from 1585 - 2620 m (5200 - 8,600 ft) in elevation. Approximately the northern half of the quadrat was composed of pinyon-juniper woodlands and grasslands. The southern portions were dominated by ponderosa pine forest, with mixed-conifer forests present at higher elevations.
We completed four survey passes over the southern half of this quadrat. We only completed two
survey passes in the northern half. A combination of extremely rugged terrain and dense
vegetation in this area made for extremely slow going. Consequently, because no owls were
heard on the northern half during the first two passes, and because continuing to survey that area
would have precluded our ability to complete four passes through the southern end, we did not
complete a third and fourth pass in the northern end of this quadrat. We located 3 confirmed
territories, which produced at least 6 juveniles. We banded all 5 of the adult/subadult owls
located and 5 of the juveniles.
Hillsboro (H24): This quadrat was located approximately 30 miles east of Silver City, in Sierra and Grant Counties, New Mexico. It straddled NM Highway 152 west of Emory Pass and south of Hillsboro Peak, and included parts or all of Railroad, Gallinas, Spring, and Noonday Canyons. The quadrat covered approximately 6,700 ha (25.8 mi2) and ranged from (1980 - 3050 m) (6500 - 10,000 ft) in elevation. Lower elevations were dominated by a mixture of pinyon, juniper, and manzanita. Upper elevations were dominated by ponderosa pine or mixed-conifer forests.
We completed four survey passes in this quadrat, and located 8 confirmed territories. We
banded 10 adult/subadult owls and 2 of the 8 juveniles located. We also located a pair of owls
late in the season along Highway 152 near the eastern edge of the quadrat, but did not classify
this area as a suspected territory because we never found them on earlier passes through the area.
We did visually confirm that this pair was unbanded.
Tonto National Forest
Buckhead Mesa (L03): This quadrat was located on the Payson Ranger District, Gila County, Arizona. The quadrat was nearly bisected by the East Verde River and was approximately bounded by Red Hill on the north and Snowstorm Mountain on the south. The quadrat also included American Gulch, Cypress Canyon, Brushy Canyon and Cedar Mesa Canyon. The majority of the quadrat was characterized by pinyon-juniper woodland broken by large patches of dense brush. The drainages were marked by the addition of Arizona cypress which in some cases formed sizable stands of closed-canopy forest. Many of the drainages also contained cliff faces which could provide roost or nest locations. The East Verde River was characterized by vegetation typical of a permanent desert river, including large Fremont cottonwood trees and undergrowth of willow and other woody vegetation. Some drainages toward the northern end of the quadrat were lined with widely-spaced ponderosa pines, but in no cases did these trees form significant forested areas. Elevation ranged from approximately 1220-1770 m (4000-5800 ft) on the quadrat.
We completed three passes on this quadrat, but did not locate any spotted owls.
The Gorge (L05): This quadrat was located on the Payson Ranger District, Gila County, Arizona. The majority of this quadrat was contained within the Mazatzal Wilderness Area. The quadrat contained nearly all of a canyon named The Gorge, from its headwaters almost to the confluence with the East Verde River. The quadrat also contained most, if not the full length, of all drainages which enter The Gorge from the north, creating a quadrat that encompassed a nearly complete watershed. The upland areas of the quadrat were characterized by volcanic rock-strewn pinyon-juniper forest interspersed with thick tangles of catclaw, wait-a-minute, manzanita, other shrubs and Opuntia cacti. Polles Mesa immediately south of The Gorge was characterized by open grassland with scattered pinyon, juniper and mesquite. The Gorge itself featured pinyon-juniper and brush-covered slopes along its upper reaches and nearly sheer cliffs as it neared the East Verde River. The canyon bottom was a patchwork of brush-choked benches and dense riparian areas marked by cottonwood and sycamore trees, springs, pools, and the diverse vegetation associated with permanent water in the desert. Elevation ranged from approximately 915-1650 m (3000-5400 ft) on the quadrat.
Three survey passes were completed on The Gorge with no spotted owls located.
Spring Creek (L06): This quadrat was located on the Pleasant Valley Ranger District, approximately 10 miles northwest of Young, Gila County, Arizona. The area was largely roadless, and encompassed part of the watershed of Spring Creek approximately from Brady Canyon to Diamond Butte. Terrain was steep and rocky, with the most dominant landscape features being Spring Creek itself and Diamond Butte. In the central portion of the quadrat, Spring Creek was a wide drainage with a dense bottom-land riparian forest of Arizona sycamore and alder. Up- and downstream from this area, Spring Creek flowed through narrow canyons with deeply incised granite walls. The uplands were dominated by pinyon-juniper woodland, with manzanita and cliffrose in the shrub layer. Cat-claw occurred on south-facing slopes at lower elevations. Scattered pockets of ponderosa pine occurred in some side drainages, along with pockets of relatively large Emory oak which formed closed-canopy stands in the drainage bottoms. Elevation ranged from approximately 1220-1920 m (4000-6300 ft) on the quadrat.
We completed four survey passes and located one suspected territory on this quadrat. The
territory was classified as suspected because we first detected an owl (a female) on 19 August.
We heard a pair of owls the following night. On 2 September we located the female at dawn in
a pocket of tall ponderosa pines up a side drainage. She moved from there to a closed-canopy
stand of Emory oak in the drainage bottom, then ceased hooting and moved to an unknown
location. We never heard or saw the male before or after the single observation on 20 August.
We were unable to band either owl on this quadrat.
Kaibab National Forest (1 quadrat)
White Horse Lake (H04): This quadrat was located on the Chalender Ranger District, Coconino County, Arizona. It included White Horse Lake and the upper reaches of Big Springs and Sycamore Canyons (in the Sycamore Canyon Wilderness). Terrain on most of the quadrat was relatively flat with small knolls and canyons. Big Springs and Sycamore Canyons featured extreme elevation changes and sheer canyon walls. Elevation ranged from approximately 1770-2350 m (5800-7700 ft). The uplands were dominated by ponderosa pine forest with scattered Gambel oak. The ponderosa pine had been logged in the past and consisted primarily of 50 100 year old trees. Sycamore Canyon and it's tributaries had mixed-conifer forest in north-facing side canyons and oak woodlands and riparian forest in the canyon bottom.
We completed four survey passes and located one nesting pair of spotted owls in this quadrat.
This pair fledged three young, and we banded all five owls. The actual nest was not located, but
the nest area was near the canyon bottom among steep cliffs and outcrops.
DISCUSSION
The field sampling conducted in 1999 provides information on the number of spotted owls detected within each quadrat. The next step required is to estimate capture probabilities, using the data on capture histories of individual owls on the quadrats and capture-recapture models for closed populations (Otis et al. 1978, White et al. 1982, Pollock et al. 1990). Once capture probabilities have been estimated, we will use these probabilities to adjust the counts of observed owls as described in Ganey et al. (1999). We can then compute density of owls per quadrat, and evaluate variance in capture probabilities and density among quadrats. These data can then be used to estimate the number of quadrats that must be sampled to allow for precise estimates of population abundance and trend.
Concurrently with the above analysis, we will also evaluate overall project logistics and
feasibility. This information can then be combined with sample-size requirements to develop
recommendations for future monitoring, including annual cost estimates. We hope to complete
this step in winter 1999-2000, and present recommendations and cost estimates to the
Leadership Team, Southwestern Region, USFS, by late winter. We are also proceeding with GIS
modeling to develop quadrat-based sampling frames for the Basin and Range-East and Basin and
Range-West Recovery Units. This work should be accomplished by summer 2000, and will
position us to move forward with monitoring in all three target Recovery Units should the
Leadership Team decide to move forward with this approach to monitoring population trend of
Mexican spotted owls.
LITERATURE CITED
Bailey, R. G. 1980. Descriptions of the Ecoregions of the United States. USDA For. Serv. Misc. Publ. 1391. Intermountain Region. Ogden, UT. 77pp.
Block, W. M., F. Clemente, J. F. Cully, J. L. Dick, Jr., A. B. Franklin, J. L. Ganey, F. P. Howe, W. H. Moir, S. L. Spangle, S. E. Rinkevich, D. L. Urban, R. Vahle, J. P. Ward, Jr., and G. C. White. 1995. Recovery Plan for the Mexican spotted owl (Strix occidentalis lucida). Vol. I. USDI Fish and Wildlife Service. Albuquerque, N.M. 172pp
Cully, J., and W. Austin. 1993. Endangered and threatened wildlife and plants: final rule to list the Mexican spotted owl as a threatened species. Fed. Register 58:14248-14271.
Forsman, E. D. 1983. Methods and materials for locating and studying spotted owls. USDA For. Serv. Gen. Tech. Rep. PNW-162. Pacific Northwest Res. Stn. Portland, OR.
Forsman, E. D., A. B. Franklin, F. M. Oliver, and J. P. Ward, Jr. 1996. A color band for spotted owls. J. Field Ornithol. 67:507-510.
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Ganey, J. L., and J. A. Dick. 1995. Habitat relationships of Mexican spotted owls: Current knowledge. Chapter 4:1-42 in: W. M.Block, F. Clemente, J. F. Cully, J. L. Dick, Jr., A. B. Franklin, J. L. Ganey, F. P. Howe, W. H. Moir, S. L. Spangle, S. E. Rinkevich, D. L. Urban, R. Vahle, J. P. Ward, Jr., and G. C. White. Recovery Plan for the Mexican spotted owl. Vol. II - Technical supporting information. USDI Fish and Wildlife Service. Albuquerque, NM.
Ganey, J. L., G. C. White, A. B. Franklin, and J. P. Ward, Jr. 1999. Monitoring population trends of Mexican spotted owls in Arizona and New Mexico: A pilot study. Study plan no. RM-4251-6-1. Rocky Mtn. Res. Stn. Flagstaff, AZ.
Johnson, C. L., and R. T. Reynolds. 1998. A new trap design for capturing spotted owls. J. Raptor Res. 32:181-182.
May, C. A., M. Z. Peery, R. J. Gutiérrez, M. E. Seamans, and D. R. Olson. 1996. Feasibility of a random quadrat study design to estimate changes in density of Mexican spotted owls. USDA For. Serv. Res. Pap. RM-RP-322. Rocky Mtn. For. and Range Exper. Stn. Fort Collins, CO.
Otis, D. L., K. P. Burnham, G. C. White, and D. R. Anderson. 1978. Statistical inference from capture data on closed animal populations. Wildl. Monogr. 62:1-135.
Pollock, K. H., J. D. Nichols, C. Brownie, and J. E. Hines. 1990. Statistical inference for capture-recapture experiments. Wildl. Monogr. 107:1-97.
Rinkevich, S. E., J. L. Ganey, W. H. Moir, F. P. Howe, F. Clemente, and J. F. Martinez-Montoya. 1995. Recovery Units. Pp. 36-51 in: W. M. Block, F. Clemente, J. F. Cully, J. L. Dick, Jr., A. B. Franklin, J. L. Ganey, F. P. Howe, W. H. Moir, S. L. Spangle, S. E. Rinkevich, D. L. Urban, R. Vahle, J. P. Ward, Jr., and G. C. White. Recovery plan for the Mexican spotted owl. USDI Fish and Wildl. Serv. Albuquerque, NM.
USDA Forest Service. 1996. Record of decision for amendment of Forest Plans. Arizona and New Mexico. USDA Forest Service, Southwestern Region. Albuquerque, NM.
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Ward, J. P., Jr., A. B. Franklin, S. E. Rinkevich, and F. Clemente. 1995. Distribution and abundance of Mexican spotted owls. Chapter 1:(1-14) in: W. M. Block, F. Clemente, J. F. Cully, J. L. Dick, Jr., A. B. Franklin, J. L. Ganey, F. P. Howe, W. H. Moir, S. L. Spangle, S. E. Rinkevich, D. L. Urban, R. Vahle, J. P. Ward, Jr., and G. C. White. Recovery Plan for the Mexican spotted owl. Vol. II - Technical supporting information. USDI Fish and Wildlife Service. Albuquerque, NM.
White, G. C., and K. P. Burnham. 1999. Program MARK: Survival estimation from populations of marked animals. Bird Study 46 Supplement: 120-138.
White, G. C., D. R. Anderson, K. P. Burnham, and D. L. Otis. 1982. Capture-recapture and removal methods for sampling closed populations. USDE Los Alamos National Lab. Los Alamos, NM.
Williams, J. L. 1986. New Mexico in maps. Univ. New Mexico Press. Albuquerque.
Table 1. General location, area and number of survey passes completed for study quadrats surveyed for Mexican spotted owls, Upper Gila Mountains Recovery Unit, 1999.
|
Quadrat No. |
Quadrat Name |
Area (km2) |
Forest |
District |
Survey Passes Completed |
| H01 | Red Mountain | 43.68 | Coconino / Kaibab | Peaks/
Chalender |
3 |
| H02 | Peaks | 61.15 | Coconino | Peaks | 4 |
| H03 | Wing Mountain | 46.45 | Coconino | Peaks | 3 |
| H04 | White Horse | 76.40 | Kaibab | Chalender | 4 |
| H07 | General Springs | 59.60 | Coconino | Blue Ridge | 4 |
| H08 | Chevelon | 55.66 | Apache-Sitgreaves | Chevelon | 4 |
| H09 | Heber | 54.88 | Apache-Sitgreaves | Heber | 3 |
| H11 | Datil | 57.92 | Cibola | Magdelena | 3 |
| H12 | Slaughter Mesa | 63.20 | Apachea | Quemado | 4 |
| H13 | Springerville | 66.77 | Apache-Sitgreaves | Springerville | 4 |
| H14 | Mangas Mountain | 68.09 | Apachea | Quemado | 4 |
| H16 | Brushy Mountain | 69.03 | Apachea | Glenwood | 3 |
| H17 | Telephone Canyon | 62.32 | Gila | Reserve | 4 |
| H18 | Pueblo Creek | 66.86 | Apachea | Glenwood/
Alpine |
2 |
| H19 | Pitchfork Canyon | 49.94 | Gila | Reserve | 4 |
| H20 | Rose Peak | 71.01 | Apache-Sitgreaves | Clifton | 4 |
| H21 | Whitewater Creek | 72.8 | Gila | Glenwood | 3b |
| H22 | Gila Cliff Dwellings | 52.45 | Gila | Mimbres | 4 |
| H23 | Tadpole Ridge | 66.26 | Gila | Silver City | 4c |
| H24 | Hillsboro Peak | 66.93 | Gila | Silver City/
Black Range |
4 |
| L01 | Lake Montezuma | 40.89 | Coconino | Beaver Creek | 3 |
| L02 | Jacks Canyon | 66.14 | Coconino | Blue Ridge | 4 |
| L03 | Buckhead Mesa | 68.53 | Tonto | Payson | 3 |
| L05 | The Gorge | 44.97 | Tonto | Payson | 3 |
| L06 | Spring Creek | 51.28 | Tonto | Pleasant Valley | 4 |
a Apache National Forest administered by the Gila National Forest.
b A third pass was largely but not completely finished.
c Four survey passes were completed on the southern half of the quadrat, which contained spotted owls. Due to time constraints, only two passes were completed on the northern half, where no spotted owls were located during the first two passes.
Table 2. Summary data for survey effort and results on 25 randomly-located study
quadrats surveyed for Mexican spotted owls in the Upper Gila Recovery Unit, 1999.
|
Quadrat |
Total Points Calleda | Points with Response | Number of Daytime Follow-upsb | Number of Follow-ups with >= 1 owl locatedc | % Successful follow-upsd | % Successful follow-ups with >= 1 owl identifiede |
| H01 | 180 | 0 | 0 | 0 | NA | NA |
| H02 | 353 | 39 | 31 | 20 | 64.5 | 85.0 |
| H03 | 201 | 0 | 0 | 0 | NA | NA |
| H04 | 360 | 13 | 8 | 4 | 50.0 | 100.0 |
| H07 | 264 | 27 | 46 | 15 | 32.6 | 20.0 |
| H08 | 343 | 18 | 14 | 12 | 85.7 | 41.7 |
| H09 | 328 | 0 | 0 | 0 | NA | NA |
| H11 | 299 | 0 | 0 | 0 | NA | NA |
| H12 | 301 | 21 | 17 | 7 | 41.2 | 0.0 |
| H13 | 364 | 11 | 10 | 7 | 70.0 | 0.0 |
| H14 | 565 | 32 | 18 | 5 | 27.8 | 20.0 |
| H16 | 465 | 35 | 39 | 15 | 38.5 | 40.0 |
| H17 | 399 | 21 | 10 | 4 | 40.0 | 75.0 |
| H18 | 251 | 23 | 17 | 9 | 52.9 | 66.7 |
| H19 | 147 | 2 | 1 | 0 | 0.0 | NA |
| H20 | 339 | 3 | 4 | 2 | 50.0 | 0.0 |
| H21 | 305 | 53 | 54 | 26 | 48.1 | 23.1 |
| H22 | 490 | 38 | 36 | 15 | 41.7 | 33.3 |
| H23 | 483 | 35 | 28 | 23 | 82.1 | 82.6 |
| H24 | 624 | 53 | 54 | 32 | 59.3 | 65.6 |
| L01 | 140 | 0 | 0 | 0 | NA | NA |
| L02 | 432 | 8 | 8 | 4 | 50.0 | 50.0 |
| L03 | 303 | 0 | 0 | 0 | NA | NA |
| L05 | 117 | 0 | 0 | 0 | NA | NA |
| L06 | 204 | 2 | 4 | 2 | 50.0 | 0.0 |
| Total | 8257 | 434 | 400 | 202 | 51 | 49 |
a Includes repeat visits to call points on successive survey passes.
b Number of follow-ups is less than twice the number of responses because a single owl was often heard from multiple points.
c "Located"=visually observed on a roost.
d (Number of follow-ups with owl(s) located/Number of follow-ups)*100
e (Number of follow-ups with owls identified/Number of follow-ups with owls located)*100,
where "identified" means owls that were captured or whose color-bands were resighted.
Table 3. Numbers of territories located and territorial Mexican spotted owls banded on 25
randomly-located study quadrats in the Upper Gila Mountains Recovery Unit, 1999.
| Territoriesa | Adults/Subadults Banded | ||||
| Quadrat Number | Confirmed | Suspected | Male | Female | Unknown |
| H01 | 0 | 0 | 0 | 0 | 0 |
| H02 | 3 | 0 | 3b | 3 | 0 |
| H03 | 0 | 0 | 0 | 0 | 0 |
| H04 | 1 | 0 | 1 | 1 | 0 |
| H07 | 1(4) | 0 | 2 | 2 | 0 |
| H08 | 1(1) | 0 | 1 | 1 | 0 |
| H09 | 0 | 0 | 0 | 0 | 0 |
| H11 | 0 | 0 | 0 | 0 | 0 |
| H12 | 1 | 1 | 0 | 0 | 0 |
| H13 | 1 | 0 | 0 | 0 | 0 |
| H14 | 0(1) | 0 | 1 | 0 | 0 |
| H16 | 4 | 0 | 4 | 3 | 0 |
| H17 | 1 | 0 | 1 | 1 | 0 |
| H18 | 2(1) | 0 | 3 | 2 | 0 |
| H19 | 0 | 0 | 0 | 0 | 0 |
| H20 | 0 | 1 | 1 | 0 | 0 |
| H21 | 9 | 2 | 4 | 4 | 0 |
| H22 | 4 | 1 | 2 | 2 | 0 |
| H23 | 3 | 0 | 3 | 2 | 0 |
| H24 | 8 | 0 | 5 | 5 | 0 |
| L01 | 0 | 0 | 0 | 0 | 0 |
| L02 | 0(1) | 0 | 0 | 1 | 0 |
| L03 | 0 | 0 | 0 | 0 | 0 |
| L05 | 0 | 0 | 0 | 0 | 0 |
| L06 | 0 | 1 | 0 | 0 | 0 |
| Totals | 40 (7 ) | 6 | 31b | 27 | 0 |
a Numbers in parentheses are the numbers of territories located with apparent activity centers (nest and/or major roost areas) outside of the quadrat boundary.
b Includes one owl previously banded during another study.
Table 4. Summary data for occupancy and reproductive status of Mexican spotted owl
territories in randomly-located study quadrats in the Upper Gila Mountains Recovery Unit,
1999. Only quadrats containing spotted owl territories (n = 18 quadrats) are included.
| Territory | Age Classb |
Reproductive Statusc |
Number of
Juveniles
Banded | |||
| Quadrat Number | Number | Statusa | Male | Female | ||
| H02 | 1 | P | A | A | 2F | 0 |
| 2 | P | A | A | NN | 0 | |
| 3 | P | S? | A | 2F | 0 | |
| H04 | 1 | P | A | A | 3F | 3 |
| H07 | 1d | P | A | A | 3F | 0 |
| 2d | P | UN | UN | 3F | 2 | |
| 3d | P | S? | UN | UN | 0 | |
| 4d | P | UN | A | UN | 0 | |
| 5 | UN | UN | UN | UN | 0 | |
| H08 | 1d | P | A | A | 3F | 0 |
| 2 | P | A | A | 3F | 0 | |
| H12 | 1 | P | A | A | 3F | 3 |
| 2e | UN | UN | UN | 0 | ||
| H13 | 1 | P | S2 | A | 1F | 0 |
| H14 | 1d | UN | S1 | UN | 0 | |
| H16 | 1 | P | A | A | 2F | 0 |
| 2 | P | S2 | A | 3F | 0 | |
| 3 | P | A | UN | 2F | 0 | |
| 4 | P | A | A | 2F | 0 | |
| H17 | 1 | P | A | A | 3F | 3 |
| H18 | 1 | P | A | S2 | UN | 0 |
| 2d | P | A | UN | 2F | 0 | |
| 3 | P | UN | A | 1F | 0 | |
| H20 | 1e | UN | UN | UN | 0 | |
| H21 | 1e | P | UN | UN | UN | 0 |
| 2 | P | A | UN | UN | 0 | |
| 3 | P | A | A | 1F | 0 | |
| 4 | P | A | A | 3F | 0 | |
| 5 | P | UN | UN | UN | 0 | |
| 6 | P | UN | S2 | UN | 0 | |
| 7 | P | UN | UN | UN | 0 | |
| 8 | P | A | A | 2F | 1 | |
| 9 | P | UN | UN | UN | 0 | |
| 10 | P | UN | UN | 1F | 0 | |
| 11e | UN | UN | UN | 0 | ||
| H22 | 1 | P | S2 | UN | 1F | 1 |
| 2 | P | S1 | A | 1F | 1 | |
| 3 | P | UN | A | 3F | 2 | |
| 4e | UN | UN | 0 | |||
| 5 | UN | UN | UN | 0 | ||
| H23 | 1 | UN | A | UN | 0 | |
| 2 | P | A | A | 3F | 3 | |
| 3 | P | A | A | 3F | 2 | |
| H24 | 1 | P | S2 | UN | NN | 0 |
| 2 | P | UN | A | 1F | 1 | |
| 3 | P | S2 | S2 | 2F | 0 | |
| 4 | UN | UN | UN | 0 | ||
| 5 | P | S1 | UN | 2F | 0 | |
| 6 | P | A | A | 1F | 1 | |
| 7 | P | A | S1 | 2F | 0 | |
| 8 | P | S2 | S1 | UN | 0 | |
| L02 | 1d | P | UN | A | NN | 0 |
| L06 | 1e | P | UN | UN | UN | 0 |
a Territory status codes: P=pair confirmed; UN=unknown pair status.
b Age-class codes: A=adult; S1=first year subadult; S2=second year subadult; S?=subadult, age unknown; UN = non-juvenile, age class unknown.
c Reproductive status codes: UN=unknown; NN=not nesting; NT=nesting, number of fledglings produced undetermined; 1F=one young fledged; 2F=two young fledged; 3F=three young fledged.
d Activity center (nest and/or major roost area) of this territory fell outside of the quadrat boundary.
e Suspected territory (see text).
Appendix 1. Scientific and common names of organisms discussed in the text.
| Scientific Name | Common Name |
| Abies concolor | White fir |
| Acacia greggii | Cat-claw |
| Acer negundo | Box-elder |
| Alnus tenuifolia | Thinleaf alder |
| Arctostaphylos spp. | Manzanita |
| Cowania mexicana | Cliffrose |
| Cupressus arizonica | Arizona cypress |
| Juglans major | Arizona black walnut |
| Juniperus spp. | Juniper |
| Mimosa biuncifera | Wait-a-minute |
| Pinus spp. | Pinyon pine |
| P. ponderosa | Ponderosa pine |
| P. strobiformis | Southwestern white pine |
| Platanus wrightii | Arizona sycamore |
| Populus angustifolia | Narrowleaf cottonwood |
| P. fremontii | Fremont cottonwood |
| Prosopis juliflora | Mesquite |
| Pseudotsuga menziesii | Douglas-fir |
| Quercus emoryi | Emory oak |
| Q. gambelii | Gambel oak |
| Robinia neomexicana | New Mexican locust |
| Salix spp. | Willow |
| Strix occidentalis lucida | Mexican spotted owl |
