Associated Species: Other species that may use similar habitat components or respond positively to management for the Northern Goshawk are: Wild Turkey, Flammulated Owl, Mexican Spotted Owl, Williamson’s Sapsucker, Northern Flicker, Steller’s Jay, Pygmy Nuthatch, Western Bluebird, American Robin, Solitary Vireo, Grace’s Warbler, Western Tanager, and Red Crossbill.

Distribution: The Northern Goshawk is Holarctic in distribution. In North America it occurs primarily in boreal forest, but the species also ranges far to the south in montane forest of the western United States and Mexico. The most widespread subspecies (A.g. atricapillus) occurs from the northeastern United States across the boreal forests of Canada to Alaska, and southward through upland forests of the western United States. Two other weakly differentiated subspecies are variously accepted in North America: A.g. laingi in forests on islands and along the coast of extreme northwestern United States and Canada to southeast Alaska (AOU 1957, Palmer 1988), and A.g. apache in montane forests of southeastern Arizona, southwestern New Mexico and northern Mexico (Hubbard 1978, Wattel 1973, Whaley and White 1994).

Ecology: Goshawks are generally non-migratory. However, in the northern portion of their range, large southward migrations occur during winters when prey are limiting (Doyle and Smith 1994, Mueller and Berger 1967, Mueller and others 1977). In the Southwestern United States, there is evidence that goshawks move to lower elevation habitats or remain on or near their breeding home range for the winter (Beier 1997, Ingraldi 1998, Reynolds pers. comm.).

Goshawks are believed to be monogamous (Newton 1979), although a few instances of "divorce" have been documented (Detrich and Woodbridge 1994, Reynolds and others 1994). Goshawks generally breed at 3 years, when they achieve full adult plumage. A few cases of subadult females (birds between 1 and 2 years of age with primarily juvenile plumage) have been documented (e.g. Henny and others 1985, Younk and Bechard 1994). No cases of breeding subadult males have been reported and one study suggested these young males are physiologically incapable of breeding (Hoglund 1964). McGowan (1975) hypothesized that subadult females are only able to breed in years of high prey availability. Several cases of both male and female young adult birds (between 2 and 3 years of age with primarily adult plumage) have been reported (McGowan 1975, Reynolds and others 1994, Younk and Bechard 1994).

Goshawks have large breeding home ranges (570–3,500 ha or 1410-8650 ac) with males’ home ranges generally larger than females’ (Squires and Reynolds 1997). Nest areas within home ranges are defended. Home ranges (but not nest areas) of adjacent pairs may overlap, especially in habitats where nesting populations are at or near saturation (Reynolds and Joy 1998). One to 8 alternate nests may be maintained in a breeding home range. One nest may be used in sequential years, but often an alternate is selected (Squires and Reynolds 1997). Males do most of the foraging while females appear to select the nest site, do most of the nest building, incubating and brooding, feed the young, and defend the nesting area. Goshawks typically initiate breeding activities in March. Egg-laying usually occurs between late April and early May and hatching between late May and early June. Females may forage in and around the nest stand during the nestling period, but males still provide most of the prey. Only the female directly feeds the young prior to fledging, which usually occurs in July. Fledglings are dependent on their parents for approximately 6 weeks, while they complete feather growth and learn to hunt (Squires and Reynolds 1997). For the first 3 weeks, fledglings tend to stay in or close to the nest stand (Kennedy and others 1994). Dipersal is abrupt, with males dispersing a few days earlier than females (Kenward and others 1993a,b; Ingraldi 1998).

Squires and Reynolds (1997) reported goshawk breeding density estimates from North American populations ranging from less than 1 pair up to 11 pairs per 100 km². Productivity in North America ranges from 1.4 to 3.9 young per successful nest (Squires and Reynolds 1997).

Goshawks prey on a variety of birds and mammals. Reptiles and insects are taken occasionally. Diets differ among populations as prey availability changes regionally and seasonally (Squires and Reynolds 1997). Important prey in the Southwest include cottontails, tree squirrels, ground squirrels, chipmunks, grouse, columbids, woodpeckers, jays and robins (Reynolds and others 1992). Goshawks are described as short duration sit-and-wait predators. They travel through the forest in a series of short flights, punctuated by brief periods of prey searching from elevated hunting perches (Squires and Reynolds 1997).

Habitat Requirements: Goshawk nesting habitat has been extensively described. Generally, goshawk nest sites are in mature and old growth forest stands with relatively high canopy closure (e.g. Austin 1993, Crocker-Bedford and Chaney 1988, Ingraldi and MacVean 1995, Kennedy 1988). Across the West, goshawks use a wide variety of forest types, but in the Southwest, goshawks primarily use ponderosa pine and mixed conifer forests, although use of other forest types (e.g. spruce-fir, Madrean oak woodland, pinyon-juniper woodland) has also been documented (Snyder 1995, USFWS 1998). In the West, goshawks nest in both deciduous trees (e.g. cottonwoods, aspen) and conifers (USFWS 1998). In the Southwest, goshawks frequently nest in ponderosa pines. Goshawks build large stick nests which are often placed on a horizontal limb close to the trunk in the low portion of the tree’s canopy (Snyder and Snyder 1998). In an Arizona study in ponderosa pine habitat (Ingraldi and MacVean 1995), goshawks selected nest sites with higher canopy density, larger diameter stems and a higher frequency of large ( 30.5 cm (12 in)dbh) stems. Nest sites also had more ground litter. Nest trees were taller, had smaller live crown ratios, tended to be part of a clump of trees with interlocking crowns, and were on the lower third of a slope. These results were similar to Kennedy’s (1988) findings in New Mexico.

Foraging habitat has been less studied. Goshawks have been observed hunting in a diversity of habitats, varying from large openings to dense forests. However, limited evidence suggests goshawks preferentially forage in forests with closed canopies (Austin 1993, Beier and Drennan 1997, Bright-Smith and Mannan 1994).

Reynolds and others (1992) described habitat relationships of primary goshawk prey in the Southwest; some prey species prefer forest openings, but most use mature and older forests. In Arizona, Beier and Drennan (1997) radio-tracked foraging goshawks to determine whether hawks selected foraging habitat based on prey abundance or forest structure. Goshawks apparently did not select foraging sites based on prey abundance; indeed, abundances of some prey were lower on used than on contrast plots. Goshawks selected foraging sites with higher canopy closure, greater tree density, and greater density of large trees (>40.6 cm (16 in) dbh). These results were consistent with the hypothesis that goshawk morphology and behavior are adapted to hunting in moderately dense, mature forests and that prey availability, as influenced by forest structure, is more important than prey density in habitat selection.

Few goshawk studies in North America have investigated winter habitat use. In Arizona, Beier (1997) found adult goshawks wintered in ponderosa pine forest and pinyon-juniper woodlands during two winters. In general, females remained in ponderosa pine in the general vicinity of their nest stands throughout both winters. Most male goshawks moved 5-10 miles from the nesting area and generally into the closest pinyon-juniper woodlands, although one male moved up into the nearest mixed-conifer forest. Most males made return trips to their nesting areas during the winter and did not establish a distinct winter range. The females appeared to exhibit more overwinter fidelity to the nest stand than males. Unlike Beier and Drennan’s (1997) breeding season study, Beier (1997) found winter foraging habitat selection could not be discerned based on vegetation structure. Used vs. unused areas were similar, with used habitat having slightly more medium-sized trees and denser canopy.

Population Objectives:

Habitat Strategy

Timber harvest practices that remove older, larger trees and simplify forest stand structure, management practices that remove dead and downed trees, and catastrophic fire are the primary management issues facing the Northern Goshawk today. Grazing that reduces or eliminates the herbaceous layer and degrades prey habitat is also a management concern. Northern Goshawks are sensitive to disturbance during the nesting season thus human activities in known nest areas and post fledging family areas (PFA) should be limited. Active management including fuel reduction programs that thin from below and use fire to maintain structural diversity in forest stands is recommended. Management practices that retain and promote large trees are also encouraged.

Northern Goshawk management issues are listed in italics. Below each issue are the Arizona Partners in Flight Conservation Recommendations.

Associated Species: Other species that may use similar habitat components or respond positively to management for the Olive-sided Flycatcher are: Flammulated Owl, Williamson’s Sapsucker, Purple Martin, Violet-green Swallow, Pygmy Nuthatch, and Grace’s Warbler.

Distribution: The Olive-sided Flycatcher’s breeding range extends throughout western North America from western and central Alaska and central Yukon, south through the Sierra Nevada Mountains to northern Baja California and through the Rocky Mountains into northern Arizona and western Texas (Altman 1997). Eastward it extends across Canada and into northeastern United States. The Olive-sided Flycatcher’s winter range extends southward as far as southeastern Brazil and western Peru with most of its wintering grounds in northwestern Venezuela, the Andes Mountains of north and western South America, and Panama (Altman 1997). In Arizona, its range is limited to north of the Mogollon Rim in higher elevation ponderosa pine and mixed conifer forests.

Ecology: Arrival on breeding grounds is generally late across its range from mid-April to late May in Arizona. Late arrival has been attributed to a higher abundance of their primary diet source, flying insects, especially honey bees (Bryant 1975, Ehrlich and others 1988, Robins 1970). The earliest nesting record in Arizona was an occupied nest found on 11 June near Happy Jack, and the latest record was a nest with young found on 1 August near Green’s Peak in the White Mountains (ABBA unpubl. data). Males are vigorous defenders of their territory and nest area (Altman 1997, Ehrlich and others 1988). Nests are generally placed high up in the tree (usually coniferous), distant from the main trunk, on a horizontal branch (DeGraaf and Rappole 1995, Ehrlich and others1988, Harrison 1975). The open cup nest is constructed of twigs, lichens, moss, and pine needles, lined with fine grasses, lichens, and rootlets and held firmly to the branch with spider webs ( Bent 1942, Ehrlich and others 1988). Departure to the wintering grounds occurs early across the flycatcher’s range, with most birds leaving breeding areas in late August through late September. This early departure may be a result of the extreme distances they travel to wintering grounds (Altman 1997). Olive-sided Flycatchers travel farther in migration than any other North American breeding flycatcher (Murphy 1989).

Habitat Requirements: In Arizona, the Olive-sided Flycatcher is primarily associated with mixed conifer forests, subalpine forests with Engelmann spruce, pure ponderosa pine forests and montane riparian wetlands with aspen, Douglas-fir, white fir and ponderosa pine (T. Corman, AGFD, pers. observ.). They prefer forest edges and openings either natural or man-made, and tend to increase in density as canopy cover decreases. Olive-sided Flycatchers have been linked to burned areas of mixed conifer and ponderosa pine (Altman 1997, Blake 1982, Lowe and others 1978). A correlation between higher densities of insects and early post-burn areas has been suggested by the presence of other insectivorous birds such as the Western Wood-Pewee and Townsend’s Solitaire (Granholm 1982). The association with burned areas may not only be for the abundance of prey but for the open and edge physiognomy in these areas as well as abundant singing and foraging perches.

The lack of natural history information for this species has made assessment of declines difficult. Loss of extensive tracts of montane evergreen forests on the wintering grounds and habitat loss through conversion to non-forest and younger successional stages on breeding grounds have been suggested as possible factors (Altman 1997). Also, management practices that alter natural fire regimes may reduce the post-fire habitat preferred by the flycatcher. Recent management practices, such as prescribed burns, that attempt to mimic natural fire regimes do create more edge and open areas, but may not capture all necessary components and resources used by the Olive-sided Flycatcher. These practices may not benefit the species as much as expected. Large territory sizes and strong site fidelity on both breeding and wintering grounds have also been speculated to contribute to declines in Olive-sided Flycatchers (Altman 1997).

Olive-sided Flycatcher management issues are listed in italics. Below each issue are the Arizona Partners in Flight Conservation Recommendations.

1. Request breeding locations from local birders.

Associated Species: Other species that may use similar habitat components or respond positively to management for the Cordilleran Flycatcher are: Red-faced Warbler, Painted Redstart, Hermit Thrush, and MacGillivray’s Warbler.

Distribution: Cordilleran Flycatcher breeds from southeastern Washington, southwestern Alberta, northern Idaho, western Montana, Wyoming, and western South Dakota south (generally east of the Cascades and Sierra Nevada) to northern California, Nevada, central and southeastern Arizona, the Mexican highlands to Oaxaca (west of the Isthmus of Tehuantepec), Puebla and west-central Veracruz, and east to western Nebraska (rarely), central Colorado, central New Mexico, and western Texas (AOU 1989). Winter range is described as southern Baja California and northern Mexico south through the breeding range. Casual winter visitor to central California and southern Arizona (AOU 1989). They are common summer residents in the boreal and transition zones throughout central and eastern Arizona (Monson and Phillips 1981). Recently, Cordilleran Flycatchers were observed nesting locally on the Kaibab Plateau (ABBA unpubl. data)

Ecology: The "Western" Flycatcher was split recently into the Pacific Slope Flycatcher (E. difficilis, previously E.d. difficilis) and the Cordilleran Flycatcher (E. occidentalis, previously E. d. hellmayri) (AOU 1989). The split of the species was based on differences in vocalizations and allozyme frequencies, and their sympatric distribution in the Siskiyou region of northern California (Johnson and Marten 1988). Phillips (1994) disputes the acceptance of these two forms as separate species. In the field, the only distinguishing characteristic between the two is the call note of the male.

In Arizona, the Cordilleran Flycatcher arrives on the breeding grounds in mid-May andleaves in September. Nest height varies from 0-9 m (0-30 ft). Their nest is a cup of green and dried leaves and moss, with finer leaves, bark strips lining the cup. Cordilleran Flycatchers are rare cowbird hosts.

Cordilleran Flycatchers prefer shady conditions, even during migration. Foraging occurs beneath the crowns of the trees; look-out and singing posts are well beneath the leafy canopy and shaded, though they may be up to 12 m (40 ft) off the ground (Grinnell and Miller 1944).

Habitat Requirements: Cordilleran Flycatcher breeding habitat includes spruce, fir, aspen, and pine forests, preferably in moist and shaded forests. It also inhabits hollows, canyon bottoms, and riparian woodlands. Natural nest sites include rock crevices, niches formed by scars in trunks (especially aspen), tree roots, cavities in small trees, and in forks of small branches (Ehrlich and others 1988, Paine and Martin 1995). They are also known to nest on rafters and out-buildings. Rock crevices provided 27%, live aspen trees 23%, and aspen snags 12% of nest sites in studies on the Mogollon Rim (Paine and Martin 1995).

Rosenstock (1996) described habitat relationships of breeding birds in northern Arizona pine forests and found significant relationships between the abundance of Cordilleran Flycatchers and several habitat characteristics. Cordilleran Flycatchers increased with increasing canopy cover and were most abundant in stands with >50% canopy cover. They were also more abundant in stands with more homogenous canopy. Cordilleran flycatchers were most abundant in stands with 5-20% of pine basal area in 1-5 inch (2.5-12.4 cm) dbh stems. Abundance was also correlated with within-stand variability of pine dbh. Cordilleran Flycatchers increased with snag density, and were most abundant in stands with >3 snags per acre. Flycatchers were also most abundant in stands with >20% of snags in decay class 2 (Thomas 1979; large limbs and stubs present, upper 10% of bole may be broken off, bark starting to slough, base solid).

Habitat and/or Population Objectives:

Management Issues with Conservation Recommendations

Breeding Bird Survey data indicate an increase in Cordilleran Flycatchers in both the western and central regions based on the years 1966-1993 (Stokes and Stokes 1996). However, there are some factors that could potentially have negative impacts on this species. Concerns about the loss of suitable habitat and habitat components ideal to the Cordilleran Flycatchers are primarily: loss of snags and downed logs for nesting and the loss of closed canopy causing reduction in cool microclimate that they are most frequently associated with.

Cordilleran Flycatcher management issues are listed in italics. Below each issue are the Arizona Partners in Flight Conservation Recommendations.

Associated Species: Other species that may use similar habitat components or respond positively to management for the Purple Martin are: American Kestrel, Lewis’ Woodpecker, Olive-sided Flycatcher, Tree Swallow, Violet-green Swallow, Pygmy Nuthatch, Western Bluebird, Mountain Bluebird.

Distribution: Breeds from southwestern British Columbia south to Baja California; and from northeastern British Columbia to New Brunswick south to Mexico, the Gulf Coast, and southern Florida. Local in the Rocky Mountains but avoids most other mountainous areas (DeGraff and others 1991). Winters in South America east of the Andes from Venezuela south to northern Bolivia and southeastern Brazil (Ehrlich and others 1988). In Arizona, they breed across the Mogollon Plateau region, extending to Williams, Mount Trumbull, the Natanes Plateau, the Sierra Anchas, and the Prescott region. Purple Martins are also found in the Chiricahua Mountains but absent from other mountains of southern Arizona. They use saguaro associations of south-central Arizona west to the Ajo Mountains and north to near Picacho, Florence, Roosevelt Lake, and the lower San Pedro Valley. Purple Martin are rare outside their breeding ranges (Phillips and others 1964).

Ecology: Purple Martins arrive in Arizona in early April and remain until early October (Phillips and others 1964). They feed on flying insects taken on the wing often at altitudes over 50 m (164 ft), and may occasionally feed on the ground. Food items include ants, wasps, beetles, grasshoppers, stink bugs, treehoppers, dragonflies, moths, butterflies, mosquitoes, horseflies, robber flies, etc. Typically, they don’t forage when temperatures are less than 9° C (48° F) or in the rain. If cold or adverse weather lasts more than 3-4 days, mortality can be substantial (Brown 1997). They drink and bathe on the wing (Ehrlich and others 1988). They gather in enormous premigratory communal roosts at the end of summer, which may include up to 100,000 birds (Ehrlich and others 1988).

Purple Martins nest in tree cavities excavated by woodpeckers, and occasionally in cliff niches. They use colonial birdhouses in the eastern United States but have not adapted to these in the West, where they tend to nest singly (Brown 1997, Phillips and others 1964). The nest is made up of grass, leaves, mud, feathers, and occasionally has a dirt rim to keep eggs from rolling out. Fresh green leaves added during incubation are thought to be used for their pesticidal properties. Cowbird parasitism is very rare; however, competition with House Sparrows and Starlings for nest sites can be high.

Considered as two subspecies in Arizona, exhibiting ecological races. Martins inhabiting the saguaro deserts (P.s. hesperia, used tentatively by Phillips 1964) are of decidedly smaller size than those found in north and central Arizona (P.s arboricola). The two habitats (and distributions) are in close proximity in the Roosevelt and Coolidge Lake areas.

Habitat Requirements: In general, Purple Martins inhabit open and cut over woodlands, open grassy river valleys, meadows around pools, shores of lakes, marsh edges, agricultural lands, saguaro deserts, parks and towns. They prefer habitats near open water. In Arizona pine forests, martins prefer areas with a high snag density, adjacent to or in open areas. The lack of Martins in apparently suitable nesting habitat suggests still unknown habitat requirements in Arizona forests.

Management Issues with Conservation Recommendations

The Purple Martin was on the Audubon Society’s Blue List from 1975-1981, and on the Special Concern list 1982-1986. Forestry practices that removed snags greatly reduced the availability of natural nest sites. Purple Martins do not use colonial nest boxes in western states, and suffer from a lack of nest sites in many areas. House Sparrows and Starlings compete for nest cavities and can cause local extinction. Brawn and Balda (1988) state that the Purple Martin has nearly been extirpated from the ponderosa pine forest since fire suppression has resulted in much denser conditions and logging has reduced the number of snags and large old trees. Currently, Purple Martins nests only in clusters of old, dead pines containing numerous woodpecker holes. Pesticide use on wintering grounds may be a potential threat.

Purple Martin management issues are listed in italics. Below each issue are the Arizona Partners in Flight Conservation Recommendations.