Flammulated owls breed in aspen, ponderosa, and Jeffrey Pines. They winter in central and south Mexico, as far south as Guatemala, Honduras, and El Salvador.

Biogeographic Regions: neotropical (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Breeding

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Breeding

Global Range: (20,000-2,500,000 square km (about 8000-1,000,000 square miles)) BREEDING: locally from southern British Columbia, western Montana, and northern Colorado south to southern California, southern Arizona, southern New Mexico, western Texas, southeastern Coahuila, Nuevo Leon (AOU 1983) (to 3700 m, Contreras-Balderas 1992), and central Mexico (Sibley and Monroe 1990, McCallum 1994a). NON-BREEDING: central Mexico south in highlands to Guatemala and El Salvador, casually north to southern California (AOU 1983).

Flammulated owls are 6 inches (17cm) in length with a wingspan of 14 inches. They have big, round heads with large dark brown eyes. The ear tufts are small. Their bill is gray or blue. There are two color morphs of this species. Birds in the Great Basin mountains are grayish and have the coarsest markings; those in the southeast are reddish. The ventral side of both morphs generally tend to be blotched with gray, black, and reddish-brown. The dorsal side of the gray morph is mainly gray with reddish-brown on the back of the neck, and on the retrices and remiges. The dorsal side of the red morph is reddish-brown. A key field mark of this species is the streak of reddish feathers along the shoulder and onto the back. This "flaming" streak is what gives this bird its Latin and common name. The young tend to have a gray upperbody and a dull white or grayish-white underbody that is barred with a grayish-rust color.

There is no sexual dimorphism between the sexes. The sexes are alike in appearance although the male and female can be distinguished by call, as the female has a higher pitched whining call.

Range mass: 1.9 to 2.9 g.

Length: 17 cm

Weight: 57 grams

• Terrestrial

The Flammulated owl is generally associated with montane forested habitats often with brushy understory. This owl may also occur in forests with mixes of oak, Douglas Fir, white fir, incense cedar, or sugar pine.

Terrestrial Biomes: forest ; mountains

Comments: BREEDING: Montane forest, usually open conifer forests containing pine, with some brush or saplings (typical of the physiognomy of pre-European settlement ponderosa pine forests). Shows a strong preference for "yellow pine," i.e. ponderosa pine (Pinus ponderosa) and Jeffrey pine (P. JEFFREYI), throughout its range (McCallum 1994b). Prefers mature growth with open canopy; avoids dense young stands. Found in cooler, semi-arid climate, with high abundance of nocturnal arthropod prey and some dense foliage for roosting (McCallum 1994a). Absent from warm and humid pine forests and mesic ponderosa pine/Douglas-fir (McCallum 1994a, Wright et al. 1997). Most often found on ridges and upper slopes (Bull et al. 1990, Groves et al. 1997).

In British Columbia, uses dry interior Douglas-fir (Pseudotsuga menziesii) where ponderosa pine may be a codominant, but pure ponderosa pine is avoided. Also sometimes in pure aspen and, locally, in spruce (Picea sp.)/Douglas-fir and lodgepole pine (Pinus CONTORTA)/Douglas-fir. Prefers forests dominated by trees more than 100 years old. Highest densities found in 140 year-old to more than 200 year-old forests; owls were restricted to forests with multi-layered canopies with an abundance of large, well-spaced trees interspersed with grassy openings up to 2 hectares in size, and where cavity-bearing snags were "moderately common" (Howie and Ritcey 1987, van Woudenberg 1999). A study in the Kamloops area that tested a habitat model in Douglas-fir/ponderosa pine found three variables to be significant predictors for occupied habitat: elevation (between 850 and 1,150 meters), age class (older stands), and canopy closure (40 to 50 percent; Christie and van Woudenberg 1997).

In California, breeds in conifer habitats from ponderosa pine up to red fir (Abies magnifica) forests (Verner and Boss 1980. In Idaho, found mostly in stands of ponderosa pine, Douglas-fir, or mixtures of the two, occasionally in stands of pure Douglas-fir or aspen where ponderosa pine absent; 65 percent of detections on upper slopes or ridges; tree densities approximately 500 per hectare; mean dbh for all trees 32 centimeters (Groves et al. 1997). In Montana, associated with mature and old-growth xeric ponderosa pine/Douglas-fir stands (Holt and Hillis 1987, Wright et al. 1997); and in landscapes with higher proportions of suitable forest and forest with low to moderate canopy closure (Wright et al. 1997).

In Colorado, shows strong preference for old-growth ponderosa pine and Douglas-fir, using older trees for foraging and singing (Reynolds and Linkhart 1992, Linkhart and Reynolds 1997). Territories consistently occupied by breeding pairs were those containing largest portion (more than 75 percent) of old-growth (200-400 years), whereas territories occupied by unpaired males and rarely by breeding pairs contained 27-68 percent old-growth (Linkhart and Reynolds 1997). Aspen (Populus tremuloides) often a component of nesting habitat in Colorado and Nevada (Reynolds and Linkhart 1987b, McCallum 1994b). In northern Utah, successfully nested in nest boxes in montane deciduous forests dominated by aspen with some scattered firs (Marti 1997). Will use pinyon-juniper stands on Colorado Plateau (McCallum 1994b). In southwest, associated mainly with ponderosa or Jeffrey pine, often intermixed with aspen or oaks (Quercus).

NEST: Most often nests in an abandoned tree cavity made by Pileated Woodpecker (Dryocopus pileatus), flicker (Colaptes sp.), sapsucker (Sphyrapicus sp.) or other large primary cavity nester, at heights from 1 to 16 meters (Reynolds et al. 1989). Uses dead, large-diameter pine, Douglas-fir or aspen tree; occasionally uses natural cavity or nest box. Nearly always nests in open conifer forest with large old trees, scattered thickets of shrubs/saplings, and clearings (McCallum 1994a). Closely associated with large, mature trees for nesting (Bull and Anderson 1978; Reynolds and Linkhart 1984, 1987a, 1987b; McCallum and Gehlbach 1988). In a New Mexico study site, preferred nesting areas that have low shrub density, high canopy height, and high importance of mature pinyon pine (Pinus edulis); nest sites had fewer shrubs in front of than behind cavity entrance; vegetation characteristics apparently more limiting than nest-tree characteristics (McCallum and Gehlbach 1988). Nest sites usually were within 50 meters of grassland; most adults did not nest in the same tree cavity in successive years despite previous success (McCallum et al. 1995). In Colorado, territories with contiguous old-growth were occupied 12 consecutive years; territories with less than 75 percent old-growth only occupied by original male (Goggans 1986, cited in McCallum 1994a).

For 33 nests studied in northeastern Oregon by Bull et al. (1990), 91 percent were in dead trees and 70 percent were in ponderosa pine. Of the 33 nests, 67 percent were created by Pileated Woodpeckers, 27 percent by Northern Flickers (Colaptes auratus), and 6 percent by decay. Used Pileated Woodpecker cavities significantly more than expected based on availability. Also: (1) average dbh of nest trees was 72 centimeters and height of nest cavity was 12 meters; (2) owls used large-diameter nest trees large enough at least for Northern Flicker cavities; (3) nests were located on ridges and upper slopes with east or south aspects; and (4) nests were in stands of more than 50 centimeter dbh ponderosa pine mixed with Douglas-fir or Grand fir (Abies grandis). See Bull et al. (1990) for information on nesting habitat in Oregon.

FORAGING: Prefers yellow pine and/or Douglas-fir for foraging, and these forest types apparently support a particular abundance of favored lepidopteran prey (McCallum 1994b). In Oregon, forage in ponderosa pine and Douglas-fir types with low to medium stem density, but show particularly preference for forest/grassland ecotone (Goggans 1986, cited in McCallum 1994b). In Colorado, preferred to forage in old-growth (more than 200 years), which was related both to an abundance of lepidopteran prey and to the open crowns and park-like spacing of trees which allowed greater room to maneuver for the owls (Reynolds et al. 1989). May focus foraging in a few "intensive foraging areas" within home range, averaging 1 hectare per range (Linkhart 1984, cited in McCallum 1994b).

ROOST: In dense vegetation, thickets, or mistletoe that provide shade and protection from predators; often roosts close to trunks in fir or pine trees, or in cavities (McCallum 1994b, USDA Forest Service 1994). In Oregon, uses mixed coniferous forest rather than pure ponderosa pine (Goggans 1986, cited in McCallum 1994a). In Colorado, uses large Douglas-firs or pines with spreading form (Linkhart 1984, cited in McCallum 1994a). Roosts close to nest (20 - 25 meters) during nestling stage and just before fledging, farther away before and after (McCallum 1994a). In British Columbia, roosted in regenerating thickets of Douglas-fir (Howie and Ritcey 1987).

MIGRATION: In wooded and open areas in lowlands and mountains, including riparian areas and breeding habitat (McCallum 1994a).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Apparently a neotropical migrant, at least in northern part of range, but migration patterns are poorly understood (Winter 1974, McCallum 1994a). No banded owl has been recovered outside vicinity of capture site (McCallum 1994b), but plausible evidence of migration is based on prey availability, empirical lack of torpor, long-distance vagrancy, and seasonal timing of observations (McCallum 1994a). Capture evidence from Arizona and New Mexico suggests that it migrates at night; captures occurred from mid-April to mid-May in spring and over a longer span from early September to late October in fall (Balda et al. 1975). Winter distribution is entirely unstudied.

In North America, spring arrivals mostly in late April and early May (McCallum 1994a). In several western U.S. states, arrives generally in April, departs by end of October (Voous and Cameron 1989). Arrives in breeding areas in central Colorado and Idaho in early May (Reynolds and Linkhart 1987b, Atkinson and Atkinson 1990). In Idaho, compilation of all distributional records showed earliest date detected 30 March, latest 17 October (Groves et al. 1997). Present in British Columbia from late April to late September (Howie 1988, van Woudenberg 1999).

DNA data indicate very low differentiation among populations in different mountain ranges in New Mexico and Utah; evidently the species exhibits long-distance natal dispersal and frequent intermountain dispersal (Arsenault et al. 2005).

Otus flammeolus are insectivores. They feed on insects, moths, beetles, and crickets. Flammulated owls are predators that sit on a perch and pounce on their prey. They hunt at night, mainly at dusk or dawn, by visually locating prey from their perch, then flying to capture it in the air or pick it off needles, branches or the ground.

Comments: Mainly hunts at night and eats nocturnal arthropods (McCallum 1994a and 1994b). Marshall (1957, cited in USDA Forest Service 1994) reported that most hunting activity occurs at dawn and dusk; McCallum (1994a, 1994b) reported that species hunts exclusively at night. Feeds on various insects (e.g., moths, beetles, grasshoppers, crickets, caterpillars; McCallum 1994a, 1994b). Moths (esp. Noctuidae and Geometridae) and beetles are especially important (Reynolds and Linkhart 1987b; Marshall 1957, cited in USDA Forest Service 1994). Possibly responds to spruce budworm outbreaks (see McCallum 1994b). May occasionally eat small mammals or birds (Bull 1978; Holt 1996), but frequency is debated (McCallum 1996). See McCallum (1994a, 1994b) for detailed information on diet composition.

Foraging tactics include hawk-gleaning, hawking, hover-gleaning, and drop-pouncing; will also glean insects from trunks and branches (Reynolds and Linkhart 1987; Zeiner et al. 1990, cited in USDA Forest Service 1994). Most foraging in Oregon and New Mexico occurred along the interface between forest or woodland and grassland (see McCallum et al. 1995). In New Mexico, sit-and-wait foraging occurred 3-50 meters from nests (McCallum et al. 1995).

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

Comments: No available estimates.

2500 to >1,000,000 individuals

Comments: Total population numbers are unavailable. In British Columbia (at the northern end of its range), estimated breeding population is at least 1200 to 1500; total population probably exceeds 3000 (van Woudenberg 1999). A secretive, inconspicuous owl. In Colorado and perhaps elsewhere, may be more common than present records indicate (Andrews and Righter 1992).

Individuals occupy same breeding territory in successive years (Reynolds and Linkhart 1987a). Territory size about 5.2 square kilometers; males show strong territory fidelity but females may disperse to adjacent territories (dispersal distance averaged 474 meters; Reynolds and Linkhart 1987a). Territory size usually remains same from year to year, even if adjacent territories unoccupied (McCallum 1994a). Territorial boundaries often occur along ridgetops (Reynolds 1987).

Singing owls move widely within home range. Male foraging, territorial defense, resting and day-roosting were confined to the home range in a Colorado study; home range size appeared to be influenced by canopy volume and range shape by topography (Linkhart 1984, cited in McCallum 1994b). Nesting home ranges vary from 5.5 to 24.0 hectares, and may diminish in size during the breeding season (McCallum 1994b). In Colorado averaged 14 hectares; foraging activity concentrated in 1-4 areas within home range (Reynolds and Linkhart 1987a). Both sexes make extra-range movements during the breeding season (Reynolds and Linkhart 1990).

Generally fewer than 4 singing males per 40 hectares in Oregon, British Columbia, and Colorado. Density of 5.3 males per square kilometer reported from California (Johnsgard 1988). Densities of singing males in Idaho averaged 0.41 per 40 hectares (Atkinson and Atkinson 1990); and in Oregon from 0.28 to 0.52 males per 40 hectares (Groves et al. 1997). Nests per 100 hectares averaged 2.9 in New Mexico, 2.1 in Colorado, and 1.4 in Oregon (not significantly different; see McCallum et al. 1995). In New Mexico, nest sites averaged 260 meters from the nearest neighbor (McCallum et al. 1995). Territories remain same size in successive years and rarely expand when a neighbor is absent (Reynolds and Linkhart 1990).

PREDATORS: Recorded predators include accipiters and Great Horned Owl (Bubo virginianus). Nest predation documented by Northern Flying Squirrel (Glaucomys sabrinus; McCallum 1994b).

COMPETITORS: Squirrels and other avian cavity nesters compete for nest cavities, and as Flammulated Owl comes late to breeding grounds, competitors may limit nest site availability. Bats may compete for nocturnal insect prey (McCallum 1994b).

Comments: During nesting period in Colorado, foraging activity peaked 15-30 min after sunset and 1-1.5 hr before sunrise; ceased activity during snow or rain (Reynolds and Linkhart 1987).

Average lifespan

Status: wild: 95 months.

Flammulated owls are cavity nesters. Most nest sites are in woodpecker holes or natural tree cavities. They lay their eggs from about mid-April through the beginning of July. Generally 1-5 eggs are laid, depending on the variations in the weather.

The eggs are incubated for 21 to 24 days, and can hatch anywhere from early June to the end of July. The young become independent in 25-32 days. The young fledge at 30-35 days, staying within about 100 yards of the nest site.

Average eggs per season: 3.

Has low reproductive rate (McCallum 1994b). Clutch size is two to four (usually two to three); incubation lasts 21-26 nights, by female (male brings food); nestling period reported as 22-24 nights and 21-23 days; fledglings are tended by both parents (divide brood, Colorado), independent about 1 month after fledging. See Johnsgard (1988) for review of egg dates. Fledging occurs in July-August. Brood size most often is two. Maximum recorded longevity in the wild is about 7-8 years (Reynolds and Linkhart 1990). In California, breeds May through October with peak activity in June and July (Zeiner et al. 1990, cited in USDA Forest Service 1994). Rates of nest success and productivity generally unknown. In New Mexico, adults were site-faithful and tended to maintain pair-bonds between years; juveniles showed little natal philopatry (Arsenault et al. 2005).

Flammulated owls are losing their habitat as a result of the human need for wood. This in turn makes it difficult for them to find a nesting site, and it also makes it hard to hide from predators. Timber harvesting in older Douglas-fir and ponderosa pine forests has the single greatest impact on Flammulated Owl breeding habitat in British Columbia by affecting cavity and prey availability. Firewood cutting and removal of "danger trees" can also reduce the availability of nest trees.

US Federal List: no special status

CITES: appendix ii

IUCN Red List of Threatened Species: least concern

Canada

Rounded National Status Rank: N3B - Vulnerable

United States

Rounded National Status Rank: N4B - Apparently Secure

Rounded Global Status Rank: G4 - Apparently Secure

Reasons: Widespread distribution in western North America; population data are inadequate for trend assessment, but loss and fragmentation of mature forest habitat suggests that populations are declining.

Global Short Term Trend: Unknown

Comments: Is currently found throughout its known historic range in "good numbers" and is not in danger of extinction (McCallum 1994a; 1994c). Data are not sufficient to track trends or model population dynamics (McCallum 1994b). Once believed rare, call-response surveys revealed them to be locally common in quality habitat and among the most abundant birds of prey in some places (McCallum 1994b). Rarely encountered on North American Breeding Bird Survey. For the northern Rockies, the few available data indicate a significant decline (Dobkin 1992). In Canada, current population trend is unknown (Fraser et al. 1999, Howie 1988); reported as "?stable" by Kirk et al. (1995).

Degree of Threat: B : Moderately threatened throughout its range, communities provide natural resources that when exploited alter the composition and structure of the community over the long-term, but are apparently recoverable

Comments: Habitat specialization and an unvarying reproductive rate, even in years of high food abundance, suggests the species is adapted to a stable environment. Populations are apparently most sensitive to variation in adult survival (McCallum 1994c). This life history strategy makes populations vulnerable to environmental perturbations (such as habitat loss or fragmentation, pesticides) and slow to recover from population declines (McCallum 1994a, 1994c). TIMBER HARVEST: Restricted primarily to forest types of commercially valuable tree species, so forest management may affect viability (McCallum 1994b). Old-growth ponderosa pine, the preferred habitat, is the most endangered forest type in the Rocky Mountain West (Illg and Illg 1994). Vulnerable to clearcutting and cutting of mature trees (Spahr et al. 1991). Loss of snags and trees for nest cavities is a serious concern and cutting of snags for firewood or during timber harvest operations presents a serious threat. Most susceptible to disturbance during peak of breeding season in June and July, and disturbance from logging activity can have a detrimental effect (USDA Forest Service 1994). Preferred habitat has declined in North America with twentieth century from timber harvesting, firewood cutting, and fire suppression. Harvest of preferred pine forests continues in Mexico. The impact of this habitat loss on populations is unknown (McCallum 1994c). PESTICIDES: Insecticides used to control forest pests may affect abundance of insect prey. Reynolds and Linkhart (1998) noted that carbaryl (specific for Lepidoptera) is used to control spruce budworm and may inadvertently reduce non-target insect species, such as the noctuid moths on which the owl heavily depends. ECOLOGICAL INTERRELATIONSHIPS: Depends on Northern Flicker (Colaptes auratus), Pileated Woodpecker (Dryocopus pileatus), sapsuckers (Sphyrapicus spp.), and other large primary cavity nesters to excavate nest cavities; loss of these species from a forest community would be disastrous. Flicker cavities are often co-opted by European Starlings (Sturnus vulgaris), reducing the availability of nest cavities for both flickers and owls. McCallum (1994a) suggested that the disappearance of the Imperial Woodpecker (Campephilus imperialis), a Mexican endemic, may have had a negative effect.

Restoration Potential: Still relatively common in appropriate habitats which offers reason for optimism, but since its habitat has declined and population trends and adult survivorship are unknown, the species deserves conservation attention. Managing for an open physiognomy of preferred forest types to restore pre-settlement stand structures (for example through thinning, selective harvest, and controlled burning) would be of benefit. However, due to the low reproductive rate and the many unknowns surrounding dispersal and demographics, populations may be slow to recover; goals and expectations for restoring or increasing populations should take a conservative and long-term view.

Preserve Selection and Design Considerations: Habitat is naturally discontinuous in some regions (such as isolated mountain ranges in Nevada, Utah and Arizona) and continuous in others (such as the Mogollon Rim, Arizona). Metapopulation structure is unknown, but patchy nature of preferred habitat in some regions, and/or habitat reduction and fragmentation of preferred forest types, could influence dispersal and viability (McCallum 1994a, 1994c). Some researchers suggest that this owl may be "semi-colonial," based on observations of clusters of calling owls with large "silent" areas between them (McCallum 1994a); however, this may be a function of habitat patchiness (Howie and Ritcey 1987). McCallum (1994a) noted that this pattern could indicate either: (1) that there are areas of suitable habitat that are unoccupied; or (2) that seemingly suitable habitat is actually suboptimal.

A landscape study in Montana found that owls did not occupy all seemingly suitable landscapes containing appropriate forest types, but occurred in landscapes that had a greater proportion of xeric ponderosa pine/Douglas-fir stands with low canopy cover. Nearest neighbor distances between owls were significantly closer in landscapes with old forests than in landscapes with young forests (Wright et al. 1997)

Management Requirements: Given the ecological changes to yellow pine forests brought about by fire suppression and early timber harvest practices in this century, habitat management calls for a return to pre-settlement forest physiognomy of open stands with mature trees. Where fire suppression has led to the accumulation of understory and "ladder" fuels, altering fire regimes and forest succession, taking a course of no management action will likely continue habitat degradation (Erickson and Toweill 1994). Returning yellow pine stands to an open structure will likely require active habitat management using selective harvest, thinning or removal of dense understory fuels, controlled burning, and protection of large snags and mature trees (Erickson and Toweill 1994, McCallum 1994c). Owls may use selectively harvested stands in xeric yellow pine and/or xeric Douglas-fir where large trees and large snags are left (Howie and Ritcey 1987, Reynolds et al. 1989, Wright et al. 1997).

Management recommendations summarized in several sources include the following: (1) maintain stands of mature trees at least 0.8 to 4 hectares in size; (2) maintain large snags larger than 30 centimeters (12 inches) dbh and more than 6 meters (20 feet) in height in adequate numbers, at least 8 snags per 40 hectares (0.8 per acre); (3) leave existing trees and snags with woodpecker cavities undisturbed; (3) preferably leave snags on ridges and upper slopes with east or south aspects and in stands of large trees that contain a high percentage of yellow pine in the overstory; (4) maintain brushy clearings and understory and small grasslands near nest stands for foraging; (5) ensure snag recruitment by retaining large, green tree replacements, especially over-mature trees (can be left in groups to reduce blowdown); (6) manage for Pileated Woodpeckers (Dryocopus pileatus) and flickers in same habitats; (7) do not apply pesticides in owl habitat; and (8) provide public education.

For the Pacific Northwest, U.S. Forest Service et al. (1993) concluded that suitable habitat could be provided by maintaining adequate numbers (around 0.24 per hectare) of large snags (over 38-50 centimeters dbh, if possible) and green tree replacements for future snags (can be left in groups to reduce blowdown).

Maintaining habitat in landscapes that contain a greater proportion of open canopy yellow pine and/or dry Douglas-fir stands and greater proportions of mature and old-growth stands may be especially important to owls (Linkhart and Reynolds 1997, Wright et al. 1997, van Woudenberg 1999).

In areas lacking cavity trees but otherwise suitable for nesting, may nest in nest boxes, including those erected for kestrels, Abert's squirrels, or those especially designed for owls (Cannings 1982, Voous and Cameron 1989, Marti 1997).

See Morgan (1994) for a review of the forest ecology of ponderosa pine and Jeffrey pine, including pre-settlement structure and impacts of human activities. See Erickson and Toweill (1994) and Wright et al. (1997) for examples of landscape-level analysis. See also Atkinson and Atkinson (1990), Bull et al. (1990), Rodrick and Milner (1991), USDA Forest Service et al. (1993), and USDA Forest Service (1994).

Management Research Needs: More information is needed on breeding biology and habitat use (Rodrick and Milner 1991, Atkinson and Atkinson 1990). Data need to be collected over longer time frames to better understand the range of habitat use and prey abundance with climatic and environmental changes over time (Christie and van Woudenberg 1997). Information on nest success and adult survivorship in relation to habitat quality at stand and landscape levels is particularly needed (Wright et al. 1997). Need to understand effects of fire suppression and various silvicultural treatments on the species at both stand and landscape levels (Groves et al. 1997). Information needed on response to habitat corridors and habitat landscape patterns; wintering habitat use and threats on wintering grounds. Information needed on population trends and viability. In order to better understand population response to widespread forest change, McCallum (1994b) suggests that a population decline or bottleneck in the past century could be revealed by using amplification of microsatellite DNA with the polymerase chain reaction (PCR) to compare genetic variation in museum specimens with current populations. See McCallum (1994d) for detailed suggestions for a coordinated research program, which would include investigations on regional variation, habitat requirements, species viability, and community interactions.

Biological Research Needs: Many aspects of life-history are still unknown, particularly metapopulation dynamics; productivity and survivorship in response to habitat quality; and winter range, habitat use, and diet. Breeding range is not fully documented, especially in Mexico, including some areas where seemingly suitable habitat exists (McCallum 1994a, 1994b). More information is needed on diet and prey availability throughout year and across range and interrelationships with community, such as predators, nest and food competitors, and cavity-excavating species.

Global Protection: Few to several (1-12) occurrences appropriately protected and managed

Needs: Protect snags and older green trees in breeding areas. Protection|of several large areas with high concentrations of |Flammulated Owls should be considered (Fraser et al. 1999).

Flammulated owls keep the population of insects down. Thus they may provide pest control.

Stewardship Overview: Breeds in the "yellow pine" belt [i.e., ponderosa pine (Pinus ponderosa) and Jeffrey pine (P. JEFFREYI)] of the western U.S. and Canada; but ranges north of the limit of ponderosa pine in British Columbia. Relatively common in appropriate habitats; however, because it is a habitat specialist that depends on large cavity-bearing snags and on commercially valuable forests, it is vulnerable to habitat loss and fragmentation. Also vulnerable to the loss of large primary cavity-nesting species, such as Pileated Woodpecker (Dryocopus pileatus), flickers (Colaptes sp.), and sapsuckers (Sphyrapicus sp.) that create nest cavities. An unvaryingly low reproductive rate, even when food is abundant, suggests that the species may not recover easily from perturbations. See McCallum (1994a, 1994b) for comprehensive coverage of the species' biology; McCallum (1994c) for a summary of conservation status.

Species Impact: May influence levels of certain nocturnal insects, and possibly responds to spruce budworm outbreaks (McCallum 1994b). A competitor for nest cavities, but most other species nest earlier in the season. Its needs conflict with commercial timber use of large trees and forests and use of snags for firewood.

Comments: The genus Megascops is recognized for New World species of Otus, except O. flammeolus, which is retained within Otus because of vocal similarity with some Old World species.

O. SCOPS and O. FLAMMEOLUS have been considered conspecific by some authors (Terres 1980).