Chapter II: Part 2

Food: Insects, including flies, ladybird beetle larvae, tent caterpillars, ants, and mayflies, were the primary food of Lewis’ woodpeckers during spring and summer (Bock 1970). Fruits and berries were the most frequently used food in late summer and fall, while winter food consisted mostly of acorns and almonds gathered and stored in crevices of dead trees, power poles, and oak bark. Hadow (1973) reported that, on snowy days when insects were inactive, Lewis’ woodpeckers in southeastern Colorado spent 99 percent of their feeding time feeding from caches of acorns and corn kernels.

Yellow-bellied sapsucker
_Sphyrapicus varius_
L 7¾″

Habitat: The yellow-bellied sapsucker (sometimes called red-naped) is most abundant along streams in mixed hardwood-conifer forests. It is also found in ponderosa pine, aspen, mixed conifer, lodgepole pine, and in mixed stands of fir-larch-pine.

Nest: Yellow-bellied sapsuckers usually nest in cavities in snags or live trees with rotten heartwood. Aspen seems to be the preferred species (Howell 1952, Lawrence 1967, Kilham 1971), but nests have also been found in ponderosa pine, birch, elm, butternut, cottonwood, alder, willow, beech, maple, and fir (Bent 1939). Kilham (1971) noted that nest trees were often infected by the _Fomes_ fungus. Nest height varies from 5 to 70 feet above ground. The same nest tree is often used repeatedly, but a new cavity is excavated each year.

Food: Sap is eaten throughout the year by the yellow-bellied sapsucker, but the amount taken and tree species used vary seasonally (Tate 1973, Lawrence 1967). The birds regularly tap one or two “favorite trees” in their area; Oliver (1970) found that these tend to be trees which have been wounded (by logging, porcupines, etc.). About 80 percent of the insect food taken consists of ants (McAtee 1911). Other insects in their diet include beetles and wasps, but none of the woodboring larvae. The fruits of dogwood, black alder, Virginia creeper, and blackberries are included in the small portion of vegetable matter eaten (Bent 1939).

Williamson’s sapsucker
_Sphyrapicus thyroideus_
L 8¼″

Habitat: This sapsucker prefers mixed conifer-hardwood forests of the Rocky Mountain region but also inhabits the subalpine spruce-fir-lodgepole zone, and ponderosa pine, Douglas-fir, and aspen forests.

Nest: The choice of tree species for nesting seems to differ between regions. Bent (1939), Packard (1945), Bailey and Niedrach (1965), Burleigh (1972), and Jackman (1975) reported Williamson’s sapsuckers nesting primarily in conifers. Other authors (Rasmussen 1941, Hubbard 1965, Tatschl 1967, Ligon 1961, Crockett and Hadow 1975) found a preference for aspens. Of 57 nests in Colorado examined by Crockett and Hadow (1975), 49 were in aspens, especially aspens infected by the _Fomes_ fungus; where pines were used, there were no suitable aspen sites nearby. In Arizona, we found 17 nests in aspen snags, 3 in aspens with dead tops, and 1 nest in a live aspen.

Food: The diet of Williamson’s sapsuckers is made up of 87 percent animal and 13 percent vegetable material (Bent 1939). Most of the animal food taken is ants, and most of the vegetable material is cambium. Like the yellow-bellied sapsucker, the Williamson’s sapsucker feeds on sap, especially in spring, and picks out “favorite trees” which it taps regularly (Oliver 1970).

Hairy woodpecker
_Picoides villosus_
L 7½″

Habitat: Hairy woodpeckers are residents of nearly all types of forest from central Canada south.

Nest: Live trees in open woodlands are preferred nesting sites of hairy woodpeckers. This species makes a nest entrance that exactly fits its head and body size (1.6 to 1.8 inches). Because this size also seems very convenient for starlings and flying squirrels, hairy woodpeckers are often troubled with invasions (Kilham 1968a, Lawrence 1967). Hairy woodpeckers will often excavate the entrance so it is camouflaged or hidden, such as on the underside of a limb. Nest heights vary from 15 to 45 feet but are commonly approximately 35 feet high. Hairies will often use the same hole year after year.

Food: Hairy woodpeckers prefer to feed on insects on dead and diseased trees (Bent 1939). Approximately 80 percent of the diet is animal matter; adult and larval beetles, ants, and caterpillars are the most frequently eaten items. The primarily insect diet is supplemented with fruit, corn, acorns, hazelnuts, and many other species (Beal 1911, Bent 1939). The males forage in trees away from the nest for large insects (usually borers) located deep in the wood. Females forage close to the nest on the surface of trees, shrubs, or on the ground for small prey (Kilham 1968a).

Downy woodpecker
_Picoides pubescens_
L 5¾″

Habitat: Downy woodpeckers inhabit most of the wooded parts of North America. They are absent or rare in the arid deserts, and not common in the densely forested regions. Favorite habitat includes open woodland, hammocks, orchards, roadside hedges, farmyards, and urban areas (Bent 1939). Occasionally, these birds nest at elevations above 9,000 feet in the central Rockies (Bailey and Niedrach 1965). Most populations are considered nonmigratory; however, there is some movement from north to south and from high elevations to the plains during winter.

Nest: Downy woodpeckers resemble common flickers in many of their nesting habits. Both prefer to excavate near the tops of dead trees in fairly open timber stands. They generally excavate new cavities each year in the same tree, but do not usually use cavities of other birds or reuse old cavities (Lawrence 1967). In the fall, these birds excavate fresh holes to use as winter roosts (Kilham 1962). Nest holes are normally 8 to 50 feet above the ground with an entrance hole 1.2 to 1.4 inches in diameter (Bent 1939).

Food: The diet is about 75 percent animal and 25 percent vegetable material. Animal material consists mostly of economically harmful insects. Kilham (1970) found that beetles, mostly wood-boring larvae, made up 21.5 percent of the diet. Other materials included ants (21 percent), caterpillars (16.5 percent), weevils (3 percent), and fruit (6 percent). Like hairy woodpeckers, downy woodpeckers have been credited with reducing forest pests (MacLellan 1958, 1959, Olson 1953).

Ladder-backed woodpecker
_Picoides scalaris_
L 7″

Habitat: Ladder-backed woodpeckers are commonly found in mesquite and deciduous woodland along streams in desert regions of the Southwest.

Nest: Ladder-backed woodpecker nests are located in a variety of trees such as mesquite, screw bean, palo verde, hackberry, china tree, willow, cottonwood, walnut and oak, usually from 2 to 30 feet above ground. Saguaro cactus, yucca stalks, and branches are sometimes used for nests, as are telephone poles and fence posts (Bent 1939, Phillips et al. 1964).

Food: Insects, especially larvae of wood-boring beetles, caterpillars, and ants, are major food items. The ladder-backed woodpecker also has been reported to eat the ripe fruit of saguaro cactus (Bent 1939).

Nuttall’s woodpecker
_Picoides nuttallii_
L 6¾″

Habitat: This western woodpecker is an inhabitant of oak woodlands, riparian woods, and chapparal west of the Sierras in California.

Nest: From a literature survey and personal observations, Miller and Bock (1972) summarized the following nest-tree data for 57 nests: 23 percent in oak, 19 percent in willow, 18 percent in sycamore, 16 percent in cottonwood, and 12 percent in alder. Cavities were excavated in dead limbs and trunks of trees, from 3 to 45 feet above ground.

Food: About 80 percent of the diet of Nuttall’s woodpecker is insects, including 28 percent beetles, 15 percent hemipterans, 14 percent lepidopteran larvae, and 8 percent ants (Beal 1911). Most of the insects are gleaned from trunk and limb surfaces or captured on the wing (Short 1971). Wild fruits, poison oak seeds, and occasional acorns make up the vegetable portion of the diet. Nuttall’s woodpeckers in California have been known to take almonds, occasionally robbing the caches of Lewis’ woodpeckers (Emlen 1937, Bock 1970).

Arizona woodpecker
_Picoides arizonae_
L 7¼″

Habitat: Arizona woodpeckers are found in live oak and oak-pine forests and canyons from 4,000 to 7,500 feet in Arizona and New Mexico.

Nest: The Arizona woodpecker excavates holes in dead branches of living trees, primarily walnuts, oaks, maples, and sycamores. One nest was reportedly located in a mescal stalk (Bent 1939).

Food: This woodpecker’s diet probably consists largely of the adult and larval stages of insects, with some fruit and acorns, but few details of food items have been reported (Bent 1939).

Red-cockaded woodpecker
_Picoides borealis_
7¼″

Habitat: Red-cockaded woodpeckers need open, mature (at least 60 year old) pine forest with a high fire occurrence (Bent 1939, Jackson 1971, Hopkins and Lynn 1971). Pine species used during breeding season include: longleaf (Crosby 1971), slash (Lowry 1960), loblolly (Sprunt and Chamberlain 1949), and shortleaf (Sutton 1967). Red-cockaded woodpeckers are on the national “Endangered species” list.

Nest: These woodpeckers prefer living pines infected with red heart rot for nesting. These trees have a soft, easily excavated interior with a living exterior, leaving the tree less susceptible to destruction by fire than a dead tree. Cavities can often be reused for at least 20 years and for several years by the same pair (Ligon 1971). The height of cavity is influenced by the location of red heart infection and the height and density of undergrowth (Crosby 1971). The majority of cavities face west, and, when found in leaning trees, are generally on the low side (Beckett 1971, Baker 1971).

Food: Insects make up the major portion of the diet of red-cockaded woodpeckers. Beal (1911) and Beal et al. (1916) examined 99 stomachs and found 86 percent insects and 14 percent vegetable matter, mostly mast. Beetle larvae (16 percent) and ants made up an important part of the year-round diet. The corn earworm can be a major food source during several weeks where conditions are suitable (Ward 1930). Plant material recorded being eaten includes wax myrtle, magnolia, poison ivy, wild grape, pokeberry, blueberry, wild cherry, black gum, and pecan (Beal 1911, Baker 1971, Ligon 1971).

White-headed woodpecker
_Picoides albolarvatus_
L 7¾″

Habitat: Open ponderosa pine forest from Washington to central California is the primary habitat of the white-headed woodpecker, but it also occurs in sugar pine, Jeffrey pine, and red and white fir forests (Grinnell and Miller 1944).

Nest: This woodpecker seems to prefer dead pines, but nests have also been found in live and dead fir, oak, and aspen. White-headed woodpeckers usually excavate a new nest cavity every year and often excavate several holes before selecting one to nest in (Bent 1939). Average nest height is 8 feet above ground.

Food: White-headed woodpeckers feed primarily on pine seeds during the winter and early spring, and on insects during the summer. Tevis (1953) determined that 60 percent of the annual diet was pine seeds and 40 percent was insects. Ants made up half of the insect food; other insects taken were woodboring beetles, spiders, and fly larvae (Beal 1911, Grinnell and Storer 1924, Ligon 1973).

Black-backed three-toed woodpecker
_Picoides arcticus_
L 8″

Habitat: The conifer forests of the north are preferred, but this three-toed woodpecker is not abundant even in its favorite habitat. Forest types include mixed conifer, lodgepole pine, white fir, subalpine fir, tamarack swamps, boreal spruce-balsam fir, Douglas-fir, and mixed hardwood-conifer.

Nest: This species usually excavates its cavities in snags or live trees with dead heartwood, especially in areas that have been burned or logged (Bent 1939). Nests are usually in spruce, balsam fir, pines, or Douglas-fir, although maple, birch, and cedar have been used.

Food: The food of this species is similar to that of the northern three-toed woodpecker. Beal (1911) found 75 percent of the food to be woodboring beetle larvae, mainly long-horned beetles and metallic woodboring beetles. Weevils and other beetles, spiders, and ants are eaten along with some wild fruit, mast, and cambium. Beal estimated that each three-toed woodpecker annually consumed 13,675 woodboring beetle larvae.

Northern three-toed woodpecker
_Picoides tridactylus_
L 7½″

Habitat: This highly beneficial woodpecker is most common in coniferous forests of the West, but does occur occasionally in the Northeast.

Nest: The northern three-toed woodpecker excavates nest cavities each year in standing dead trees or in dead limbs of live trees with rotted heartwood (Jackman and Scott 1975). Their nest cavities have been reported in pine, aspen, spruce, and cedar trees (Bent 1939). In Arizona, we found two nests in ponderosa pine snags.

Food: The northern three-toed woodpecker is probably one of the most important birds in combating forest insect pests in the western United States. Massey and Wygant (1973) found that spruce beetles comprised 65 percent of their diet in Colorado. During the winter when other foods were scarce, the spruce beetle made up 99 percent of the food taken. West and Speiers (1959) reported that both species of three-toed woodpeckers in northeastern United States feed on elm bark beetles, which carry Dutch elm disease. Koplin (1972) estimated that 20 percent of an endemic and 84 percent of an epidemic spruce beetle population in Colorado were consumed by three species of woodpeckers, the most important of which was the northern three-toed. Other foods include ants, woodboring and lepidopteran larvae, fruits, mast, and cambium (Beal 1911, Massey and Wygant 1973).

Ivory-billed woodpecker
_Campephilus principalis_
L 18″

Habitat: Cooke (1888) and Bent (1939) described the largest of the North American woodpeckers as rare, shy, and found only in the heaviest timber in virgin cypress and bottomland forest of the South. Tanner (1942) described ivory-billed woodpecker habitat as heavily forested and usually flooded alluvial land bordering rivers, made up of oaks, cypress, and green ash. The most recent sightings (between 5 and 10 pairs) have been made in bottomland hardwoods that have been cut over but still have some large, mature trees (Dennis 1967). They are included on the national “Endangered species” list.

Nest: Nest cavities of this species have been recorded in almost every species of tree occurring within the ivory-bill’s habitat (Greenway 1958). The squarish holes (Dennis 1967) are high, 16 to 65 feet, and in the trunks of living or dead trees (Greenway 1958, Forbush and May 1939).

Food: Ivory-billed woodpeckers could be of economic importance except for their small numbers (Greenway 1958). The woodboring larvae making up a third of their diet (Beal 1911) are injurious to trees (Pearson 1936), and are most abundant in areas where recently dead and dying trees are numerous because of flooding, fire, insect attacks, or storms. The birds stay as long as there are abundant larvae (Dennis 1967). They also eat fruit of magnolia and pecan trees (Beal 1911).

Sulphur-bellied flycatcher
_Myiodynastes luteiventris_
L 6¾″

Habitat: The sulphur-bellied flycatcher is a common occupant of riparian habitat with sycamore trees in deep canyons from 5,000 to 7,500 feet elevation in the Huachuca Mountains of Arizona.

Nest: Invariably the nest of this species, made from leaf stems (Peterson 1961), is built in a natural cavity in a large sycamore at a height between 20 and 50 feet above the ground. The cavity normally is a knothole where a large branch has broken off (Bent 1942). At least one member of each pair may return to the same nest site each year.

Food: Little information has been published on the food habits of this flycatcher, but insects caught in the air are undoubtedly the major items. Apparently small fruits and berries also are eaten (Bent 1942).

Great crested flycatcher
_Myiarchus crinitus_
L 7″

Habitat: Great crested flycatchers are common in deciduous and mixed woods east of the Rockies. They were originally a deep forest bird, but with increases in forest clearing and thinning operations, fewer and fewer cavities are available. They seem to be adapting well to less densely forested areas, areas treated with herbicides, and forest-field edge situations (Hespenheide 1971, Bent 1942).

Nest: Great crested flycatchers use natural cavities or excavations made by other species. Nests are found in a variety of tree species anywhere from 3 to 70 feet above the ground (mostly below 20 feet). They build a bulky nest, and therefore prefer deep cavities. Before constructing a nest, they will generally fill a deep cavity with trash to a level of 12 to 18 inches from the top. They are well known for their habit of including a snake skin in the nest or dangling it from the cavity opening (Bent 1942).

Food: Food habit studies have shown that great crested flycatchers eat 94 percent animal and 6 percent vegetable material. Most frequently eaten are butterflies, beetles, grasshoppers, crickets, katydids, bees, and sawflies. Vegetable matter is mainly wild fruits. Most food is caught in flight in the usual flycatcher fashion (Bent 1942).

Wied’s crested flycatcher
_Myiarchus tyrannulus_
L 7¼″

Habitat: Desert saguaros, deciduous woodlands and riparian vegetation in the Southwest are the preferred habitats of the Wied’s crested flycatcher.

Nest: Nests made from twigs, weeds, and trash are built in abandoned woodpecker holes in saguaro cacti at a height from 5 to 20 feet above the ground. Sycamores, cottonwoods, and fence posts are used occasionally (Bent 1942).

Food: The diet of this species is similar to that of other crested flycatchers, consisting mostly of beetles, flying insects, and perhaps some berries and fruits (Bent 1942).

Ash-throated flycatcher
_Myiarchus cinerascens_
L 6½″

Habitat: The ash-throated flycatcher occupies dense mesquite thickets, oak groves, saguaro cactus, riparian vegetation, and pinyon-juniper forests. It ranges from Washington to the southwestern United States and Texas.

Nest: The ash-throated flycatcher is not particularly specific in tree selection as long as it has a cavity. Woodpecker holes, exposed pipes, and nest boxes have been used. Mesquite, ash, oak, sycamore, juniper, and cottonwood are common nest trees (Bent 1942).

Food: The diet of this species consists mainly of animal material. Beetles, bees, wasps, bugs, flies, caterpillars, moths, grasshoppers, spiders, etc., make up about 92 percent of the diet. Mistletoe, berries, and other fleshy fruits account for the remainder (Bent 1942).

Olivaceous flycatcher
_Myiarchus tuberculifer_
L 5¾″

Habitat: Olivaceous flycatchers are found in dense oak thickets, pinyon-juniper forests, and along canyon streams in Arizona and southwestern New Mexico.

Nest: Nests are located in natural cavities or abandoned woodpecker holes. Oaks are preferred, but nests also have been reported in ash and sycamore trees (Bent 1942).

Food: Limited evidence on food habits of this species indicates that the major food items are small insects including grasshoppers, termites, mayflies, treehoppers, miscellaneous bugs, moths, bees, wasps, and spiders (Bent 1942).

Western flycatcher
_Empidonax difficilis_
L 5″

Habitat: Moist deciduous or coniferous forests and areas near running water with tall trees are favored by the western flycatcher (Grinnell and Miller 1944).

Nest: Western flycatchers sometimes nest in cavities, but use a variety of nest sites. Davis et al. (1963) found four nests in natural cavities in willows and oaks, and six behind flaps of bark in sycamores and willows. Nests are often reported in natural rock crevices, on tree limbs and crotches, and on ledges of buildings (Bent 1942, Davis et al. 1963, Beaver 1967).

Food: Almost all of the food of the western flycatcher is insects captured on the wing. An examination of 23 stomachs showed 31 percent flies, 25 percent beetles, 23 percent lepidopterans (including pupae and adults of spruce budworms), and 17 percent hymenopterans (Beaver 1967).

Violet-green swallow
_Tachycineta thalassina_
L 4¾″

Habitat: Ponderosa pine affords the favorite habitat for violet-green swallows (Bailey and Niedrach 1965), but they are also found in aspen-willow and spruce-aspen forests. They prefer open or broken woods or the edges of dense forests.

Nest: Violet-green swallows nest in holes, cavities, and crevices in a variety of situations. Where birds are abundant, the demand for nest sites is sometimes greater than the supply, and practically any available cavity may be used. These swallows have been reported to use old nests of cliff swallows and even burrows of bank swallow (Bent 1942). Winternitz (1973) reported violet-greens using old woodpecker holes in live aspen as nesting sites, but in Arizona, we found them nesting primarily in old woodpecker holes in ponderosa pine snags. We found one in the dead top of an aspen, 5 in dead tops of ponderosa pine, and 26 in ponderosa pine snags. Nest heights ranged from 16 to 80 feet and averaged 43 feet.

Food: Apparently, the diet of this species is exclusively insects taken on the wing. It includes leafhoppers, leaf bugs, flies, flying ants, and some wasps, bees, and beetles (Bent 1942). In Colorado, Baldwin (pers. comm.[7]) found that insects made up 99 percent of the stomach contents of six violet-green swallows. Flies were the most abundant insect found. Scolytid beetles, seed and leaf bugs, miscellaneous insects, and a few spiders were also found.

Tree swallow
_Iridoprocne bicolor_
L 5″

Habitat: Tree swallows breed throughout North America from the northern half of the United States north to the limit of tree growth. They are migrants throughout the Central and Southern states and winter primarily in Central America.

Nest: Tree swallows prefer to nest in natural cavities and old woodpecker holes—usually near water. The lack of natural cavities, competition for existing cavities, and the availability of nest boxes, have resulted in a shift in nesting preferences to nest boxes in the eastern United States (Bent 1942, Low 1933, Whittle 1926). Bluebird boxes and purple martin houses are frequently used. Tree swallows are not colonial, but will nest within 7 feet of each other, if there are adequate meadows, marsh, or water area available for feeding (Whittle 1926). Woodpecker holes in aspen, spruce, and pine are the most common nest sites in the West (Bailey and Niedrach 1965).

Food: This species is the first of the swallows to arrive in the north in the spring, and the last to depart in the fall. Because tree swallows can subsist on seeds and berries, they are not as dependent upon insects as are other swallows. They are partial to waxmyrtle and bayberry where these are available. Plant food proportions in the diet are 1 percent in spring, 21 percent in summer, 29 percent in fall, and 30 percent in winter (Martin et al. 1951, Forbush and May 1939).

Purple martin
_Progne subis_
L 7″

Habitat: The natural nesting population of purple martins prefer open woodlands or cutover forests where suitable snags remain. Purple martins have been reported in oak, sycamore, ponderosa pine, Monterey pine, spruce, and fir forests of California (Grinnell and Miller 1944). In the Southwest, the purple martin breeds in the ponderosa pine belt and in the saguaro cactus desert.

Nest: The western purple martin has not adapted to nesting in boxes as well as the eastern form (Bunch 1964), and much of the western population depends upon holes made by woodpeckers, usually in tall pines in relatively open timber stands (Bent 1942). Martins also nest in old woodpecker holes in saguaro cactus. We have recorded 21 nests near Cibecue, Arizona, all in ponderosa pine snags. Nests ranged from 25 to 35 feet above ground. Nest compartments in martin houses should be 6 × 6 × 6 inches with an entrance hole 2½ inches in diameter 1 inch above the floor. The boxes should be 15 to 20 feet above ground.

Food: The purple martin feeds on the wing, and nearly all the diet is insects, although some spiders are taken (Beal 1918). Johnston (1967) examined the stomach contents of 34 martins collected in April, May, June, and August in Kansas. Beetles, true bugs, flies, bees, and wasps were the important food items. Although the purple martin has been credited for feeding on large numbers of mosquitoes (Bent 1942), it was not documented by the two food habit studies mentioned.

Black-capped chickadee
_Parus atricapillus_
L 4½″

Habitat: Black-capped chickadees nest throughout southern Canada and the northern half of the United States. In Missouri, the black-capped chickadee generally nests north of the Missouri River and the Carolina chickadee nests south of the River. The breeding range extends farther south at higher elevations of the Rocky and Appalachian Mountain ranges than in non-mountainous areas. In Colorado, black-caps are most abundant in the ponderosa pine and aspen forests (Bailey and Niedrach 1965).

Nest: Chickadees nest in cavities but roost anywhere convenient, generally not in cavities (Odum 1942). The most suitable nesting sites are stubs with partially decayed cores and firm shells. They usually excavate their own cavities, but will use natural cavities or nest boxes. Black-caps will occasionally nest in a cavity they used the previous year after making some alterations. Preferred nesting sites throughout the eastern forests are tree species that occur in the early seral stages but that are short lived and persist in the intermediate stages as decaying stubs (Odum 1941, Brewer 1961).

Food: The diet of the black-capped chickadee is comprised of 70 percent animal and 30 percent vegetable matter. Mast, chiefly from coniferous trees, and fruits of bayberry, blackberry, blueberry, and poison ivy make up the bulk of the vegetable matter. Animal material eaten (mostly insects) includes caterpillars, eggs, moths, spiders, and beetles. Winter diet is primarily larvae, eggs, katydids, and spiders (Bent 1946, Martin et al. 1951).

Carolina chickadee
_Parus carolinensis_
L 4¼″

Habitat: The Carolina chickadee, which inhabits the southeastern forests, is a slightly smaller version of the black-capped chickadee. In Missouri, the Carolina chickadee nests south of the Missouri River throughout the Ozarks.

Nest: The nesting habits of the black-capped and Carolina chickadees are quite similar. They occasionally nest in natural cavities or deserted holes of woodpeckers, but commonly excavate their own nest cavity in decaying wood of dead trunks or limbs of deciduous trees (Bent 1946). Black-capped and Carolina chickadees line their nesting cavities with fine grasses and feathers.

Food: Food habits of the Carolina chickadee are also very similar to those of the black-capped chickadee. Food consists of insects and a variety of fleshy fruits and seeds (Bent 1946).

Mexican chickadee
_Parus sclateri_
L 4¼″

Habitat: This species inhabits pine and spruce forests from 7,000 to 10,000 feet elevation just inside the United States in the Chiricahua Mountains of Arizona and the Animas Mountains of New Mexico (Phillips et al. 1964).

Nest: Mexican chickadees excavate nest holes in dead trees or branches. One nest was found in a willow stub about 5 feet above the ground (Bent 1946).

Food: No information on diet was found in the literature.

Mountain chickadee
_Parus gambeli_
L 4¼″

Habitat: This common little chickadee can be found in most coniferous forests of the West from 6,000 to 11,000 feet (Bent 1946).

Nest: Mountain chickadees usually nest in natural cavities or abandoned woodpecker holes, and probably do not excavate their own cavities if suitable ones are available (Bent 1946). Winternitz (1973) reported five nests in live aspen and one in a dead aspen, 6 to 15 feet above ground. In Arizona, we have found five nests in live aspen, three in aspen snags, two in ponderosa pine snags, and one in a white fir snag.

Food: Insects probably make up a large portion of the diet (Bent 1946). Telford and Herman (1963) collected 10 birds in the Inyo National Forest, where there was an infestation of lodgepole needle miners and found 639 needle miner caterpillars in chickadee stomachs. Baldwin (pers. comm.[8]) examined the contents of 17 stomachs from the Wet Mountains, Colorado, and found that 75 percent of the summer diet was insects. Large numbers of spruce aphids were found, as well as flies, beetles, hymenopterans, and other insects. Vegetable material included seeds, spruce buds, and fruits. In southwestern Montana, during summer, mountain chickadees fed on lepidopteran larvae, especially cone worms and spruce budworms (DeWeese et al.[9][in prep.]), and insects made up about 98 percent of the diet.

Gray-headed chickadee
_Parus cinctus_
L 4¾″

Habitat: Broken forests or edges of aspen, willow, and spruce are the preferred habitat of the gray-headed chickadee. The range is limited to western Canada and Alaska.

Nest: Old woodpecker holes or natural cavities are selected as nest sites. Bent (1946) reported one nest about 6 feet above ground in a spruce snag.

Food: No information could be found in the literature on the food habits of the gray-headed chickadee, but the diet is probably similar to that of other chickadees.

Boreal chickadee
_Parus hudsonicus_
L 4¼″

Habitat: The boreal chickadee is fairly common in northern forests of spruce, fir, aspen, and birch (McLaren 1975).

Nest: Natural cavities, old woodpecker holes, or cavities excavated by the chickadees themselves are used for nesting (Bent 1946). McLaren (1975) found 22 nest holes, all in trees or snags with soft heartwood, and believed that softness of the core rather than a preference for a certain tree species is the determining factor in nest site selection.

Food: In summer the boreal chickadee consumes caterpillars, moths, beetles, other insects, and insect eggs; birch cones, seeds, and cedar berries are eaten in the fall and winter (Bent 1946).

Chestnut-backed chickadee
_Parus rufescens_
L 4¼″

Habitat: Coniferous forests of the humid coastal belt from Alaska to central California are the favorite habitat, but this bird is also found in adjacent deciduous woodlands and along streams (Peterson 1961, Grinnell and Miller 1944).

Nest: Nests of this species are in abandoned woodpecker holes or in cavities excavated by the bird itself. Nests have been found in pine, oak, and Douglas-fir snags (Bent 1946).

Food: The diet is made up of about 65 percent animal and 35 percent vegetable matter. Of the animal material, 25 percent is hemipterans, 18 percent caterpillars, 13 percent wasps, 7 percent spiders, and 2 percent beetles. Seeds and fruit make up the vegetable material (Beal 1907).

Tufted titmouse
_Parus bicolor_
L 5½″

Habitat: The tufted titmouse is the largest North American titmouse and is common throughout the eastern deciduous woodlands. These active and vocal birds are generally found in groups of 2 to 6 in thick timber stands, often near water (Gillespie 1930). The black-crested titmouse, found in southern Texas and northeastern Mexico, is now considered conspecific with the tufted titmouse (33rd supplement, A.O.U. Checklist).

Nest: Nests of the tufted titmouse are very difficult to locate and are not often reported in the literature. Published accounts indicate that these birds nest in abandoned woodpecker holes or natural cavities usually less than 20 feet above the ground. While titmice are quite conspicuous in late fall and winter, they tend to disappear in late spring to nest and molt (Gillespie 1930, Laskey 1957).

Food: The diets of tufted titmice change seasonally. In spring and summer they eat primarily animal matter (89 percent and 82 percent respectively) and spend most of their feeding time in the tree tops. Caterpillars often make up over 50 percent of the animal matter. Common winter foods consist of beechnuts, acorns, dogwood berries, Virginia creeper berries, alder seeds, honeysuckle, seeds of tulip-tree pods. In winter, they spend a larger percentage of their feeding time on or near the ground (Gillespie 1930, Martin et al. 1951).

Plain titmouse
_Parus inornatus_
L 5″

Habitat: Oak and pinyon-juniper woodlands from 5,000 to 7,000 feet elevation from Oregon south and west to Texas and New Mexico are the favored habitat of the plain titmouse.

Nest: Plain titmice usually nest in natural cavities or old woodpecker holes. Most reported nests have been in oaks, 2 to 23 feet above ground (Bent 1946). Nest boxes are used when available (Wetmore 1964).

Food: Beal (Bent 1946) examined the contents of 76 stomachs and found 43 percent animal material (true bugs 12 percent, caterpillars 11 percent, beetles 7 percent, ants and wasps 6 percent, daddy longlegs and grasshoppers 5 percent, spiders 1 percent, and 1 percent unreported) and 57 percent vegetable matter (cherries and pulp of larger fruit and leaf galls 32 percent, seeds of poison oak and weeds 25 percent).

Bridled titmouse
_Parus wollweberi_
L 4½″

Habitat: Bridled titmice prefer chaparral and pinyon-juniper in the Southwest at elevations from 5,000 to 7,000 feet. This titmouse also uses areas along streams where cottonwoods are present (Phillips et al. 1964).

Nest: Almost all nest locations have been recorded in natural cavities of dead and living oak trees from 4 to 28 feet above the ground (Bent 1946).

Food: No published information was found, but the diet is probably similar to that of other members of this genus. All live in similar habitats and spend much of their time foraging in crevices in the bark, on the trunks, and on branches, presumably hunting for adults, larvae, and eggs of insects (Bent 1946).

White-breasted nuthatch
_Sitta carolinensis_
L 5″

Habitat: White-breasted nuthatches are non-migratory in most forest types in the United States. They show a preference for deciduous woodlands. In the Rocky Mountains, they occur most commonly below 9,500 feet elevation (Bailey and Niedrach 1965).

Nest: White-breasted nuthatches nest almost exclusively in natural cavities within living trees of mature forests. When natural cavities are unavailable, they may use an abandoned woodpecker hole (Kilham 1968b). In the West, nests have been found in dead aspens and dead portions (lightning strikes) of live ponderosa pines (Bailey and Niedrach 1965, Scott and Patton 1975). Nests are lined with hair and feathers and are often used for more than 1 year.

Food: A myriad of insects, including larvae of the gypsy moth and the forest tent caterpillar, beetles, spiders, caterpillars, and ants comprise the main diet of white-breasted nuthatches throughout the spring and summer. In the winter, nearly all food eaten is mast composed of beechnuts, acorns, hickory nuts, maize and sunflower seeds (Bent 1948). Among the insect foods are several other forest pests including nut weevils, locust seed weevils, and roundheaded woodborers (Scott and Patton 1975). Nuthatches may also be attracted to feeders with suet and sunflower seeds.

Red-breasted nuthatch
_Sitta canadensis_
L 4″

Habitat: Red-breasted nuthatches nest throughout the high elevations of the Rocky Mountains and in the Canadian boreal forests. They are erratic winter migrants to the eastern forest types. In Colorado, their preferred habitat is the coniferous-aspen type from the Canadian Life Zone to timberline.

Nest: Red-breasted nuthatches will excavate their own cavity if a natural cavity or woodpecker hole is not available or to their liking (de Kiriline 1952). Nests are usually 6 to 40 feet above the ground in rotten stubs or branches of dead trees. Nests have been reported in birch, poplar, cottonwood, oak, and pine. Nests usually are not lined, in contrast to those of white-breasted nuthatches.

Food: Little is known of the food taken by red-breasted nuthatches. They feed on seeds of pine, spruce, and other coniferous trees. The animal food is known to include beetles, hymenoptera, spiders, and ribbed pine borers. They sometimes feed on flying insects (Bent 1948). Birds will visit feeders offering suet during the winter.

Brown-headed nuthatch
_Sitta pusilla_
L 3½″

Habitat: Clearings and areas that have been burned (more old stumps available for nesting) in southern pine woods are preferred by brown-headed nuthatches. They can also be found in mixed pine and hardwood forests of extreme southeastern United States (Bent 1948).

Nest: Brown-headed nuthatches excavate or partially excavate nest cavities 4.5 to 8 inches deep in dead trees and stumps (often fire blackened) or posts and poles. Bent (1948) gave little evidence that the brown-headed nuthatch will use old woodpecker holes, but they may enlarge and use natural cavities. The nests are located 3 to 46 feet from the ground (only rarely above 13 feet). Because nest entrances are more like a crack in a tree than rounded like a woodpecker hole, nests are difficult to find (Pearson 1936).

Food: Brown-headed nuthatches are mainly insectivorous, and are considered a useful protector of trees. They search for insects and their eggs in crevices of the bark on the trunks, branches, twigs, and needles of pines. They also eat pine seeds (Bent 1948).

Pygmy nuthatch
_Sitta pygmaea_
L 3½″

Habitat: Pygmy nuthatches are common in ponderosa pine forests throughout the West. They are also found in Jeffrey pine, Bishop pine, and Monterey pine associations in California (Grinnell and Miller 1944), and in pinyon-juniper woodlands in Arizona (Phillips et al. 1964).

Nest: Nearly all reported nests of the pygmy nuthatch have been from 8 to 60 feet above ground in cavities excavated by the bird itself in dead or live pine trees (Bent 1948). We found 27 nests in ponderosa pine snags and two in dead aspens in the White Mountains of Arizona.

Food: About 80 percent of the diet is animal material, mostly wasps and spittle insects, including some ants, beetles, and caterpillars; the balance is nearly all conifer seeds (Bent 1948).

Brown creeper
_Certhia familiaris_
L 4¾″

Habitat: This inconspicuous small bird is fairly common in the coniferous forests of the Transition and Canadian Life Zones. In Colorado, it breeds from 7,000 feet to timberline (Bailey and Neidrach 1965). Creepers winter throughout the forests of the southern states.

Nest: Sometimes creepers nest in natural cavities and old woodpecker holes, but generally they make their nests between the loose bark and the trunk of a large dead tree (Bent 1948). We found three nests behind the loosened bark of dead ponderosa pines and one in a white fir snag in the White Mountains of Arizona.

Food: Few details are known, but the diet is mainly insects, including weevils, leafhoppers, flat bugs, jumping plant lice, scale insects, eggs of katydids, ants and other small hymenoptera, sawflies, moths, caterpillars, cocoons of leaf skeletonizers, pupae of the codling moth, spiders, and pseudoscorpions (Bent 1948). The small amount of vegetable material eaten is chiefly mast.

House wren
_Troglodytes aedon_
L 4¼″

Habitat: House wrens are common nesters in shrubbery and brush throughout the northern two-thirds of the United States, but they winter in the southern states. They range from the plains to timberline throughout the Rocky Mountains. They are commonly found along the edges of woods, swamps, fields, and in orchards.

Nest: House wrens are aggressive in their nesting habits and will drive other birds from cavities. Nests have been found in a variety of sites including 2-inch pipes used to brace fence posts, nesting boxes, natural cavities, and downy woodpecker holes (Sutton 1930). Nests are usually less than 10 feet above the ground. Diameter of the entrance hole in nesting boxes should be 1 inch.

Food: House wrens are capable of eating large quantities of insects and arthropods, which constitute 98 percent of their diet. Animal items include beetles, caterpillars, bugs, grasshoppers, and ants (Bent 1948).

Brown-throated wren
_Troglodytes brunneicollis_
L 4″

Habitat: Brown-throated wrens inhabit oak forests, mostly in desert ranges, but can be found up to elevations of 8,000 feet in southern Arizona.

Nest: This wren uses natural cavities or old woodpecker holes in tree trunks or limbs. Like the house wren, it will sometimes occupy recesses about buildings and nest boxes (Pough 1957).

Food: We could not find published information on food habits but the diet is probably insects similar to that of other wrens.

Winter wren
_Troglodytes troglodytes_
L 3¼″

Habitat: Winter wrens inhabit coniferous forests of spruce, fir, and pine, and underbrush in woodlands in eastern and western United States and Canada.

Nest: Winter wren nests, made from twigs and leaves, are built near the ground in exposed roots or fallen logs or in rocks and crevices (Bent 1948, Wetmore 1964).

Food: Details on food items were not found in the literature, but the diet is probably adult and larval stages of insects (Bent 1948).

Bewick’s wren
_Thryomanes bewickii_
L 4½″

Habitat: Bewick’s wrens are common and widespread in the West, but uncommon and local in the Appalachians and Ozarks. They are usually found in farmyards, brushlands, fencerows, and suburban areas. Bewick’s wrens are fairly common in the pinyon-juniper forest type, and in mesquite-willow-cottonwood associations along southwestern streams.

Nest: Nests of the Bewick’s wren can be found in a multitude of places. Most nests are cup-shaped and can be either open or closed above. They are usually located in cavities close to the ground (Miller 1941). Nest sites include natural cavities, woodpecker holes, knotholes in fallen trees, fence posts, tin cans, bird boxes, and deserted automobiles (Bent 1948).

Food: Bewick’s wrens, like other wrens, eat large numbers of insects that are injurious to vegetation. Ninety-seven percent of the diet is insects, including primarily hemiptera and coleoptera. In the South they are credited with eating boll weevils (Bent 1948).

Carolina wren
_Thryothorus ludovicianus_
L 4¾″

Habitat: Carolina wrens are common in forest types with thick underbrush throughout the eastern United States. The number in northern populations fluctuates widely depending on the harshness of winter conditions.

Nest: Carolina wrens are quite universal in their choice of nesting sites. These wrens prefer nesting sites that are fairly well enclosed, but they are not totally dependent upon cavities. They are well adapted to habitat conditions provided by man, but also nest in the woods where they prefer tangles and brushy undergrowth. Nests have been found in natural cavities, mailboxes, newspaper cylinders, old hornet nests, and bird houses (Laskey 1948, Nice and Thomas 1948).

Food: Animal food, mostly insects, makes up 93 percent of the Carolina wren’s diet. Of this, beetles, caterpillars, and moths comprise the largest portion. The 7 percent vegetable material is mostly seeds taken in the winter. Since the Carolina wren feeds mostly on or near the ground, deep snow is detrimental to survival. They will visit feeding stations if placed near brush piles (Bent 1948).

Eastern bluebird
_Sialia sialis_
L 5½″

Habitat: Under natural conditions, eastern bluebirds prefer to use cavities in savannah-like habitats east of the Great Plains (Rustad 1972). They are an edge species and therefore do not live in dense woods or in closely built residential sections of town (Thomas 1946). Like purple martins, bluebirds have taken advantage of nest boxes provided in areas around farms, near open fields, and in orchards.

Nest: Eastern bluebird nesting sites (snags) are often eliminated because of their unsightliness or interference with cultivation. When available, eastern bluebirds nest in old woodpecker holes, hollows of decayed trees, and crevices of rocks (Pearson 1936). They will readily take to hollows in wooden fence posts or correctly sized and placed nest boxes (5 × 5 × 8 inches high with a 1.5-inch hole located 6 inches from the bottom). Boxes should be placed 5 to 10 feet above the ground at the edge of a forest opening or field.

Food: Eastern bluebirds consume 70 percent animal matter and 30 percent vegetable matter. Vegetable intake increases to more than 50 percent in December and January, but is completely lacking in May. Animal matter includes grasshoppers, crickets and katydids, various coleoptera, moths and caterpillars, some hymenoptera and hemiptera, as well as various other invertebrates and small vertebrates. Vegetable matter is mostly wild fruits (Bent 1949).

Western bluebird
_Sialia mexicana_
L 5½″

Habitat: The western bluebird is most abundant in open ponderosa pine forests of the Transition Zone, but may also be found in oak woodlands, pinyon-juniper, mixed conifer, and subalpine forests.

Nest: Nests are usually in old woodpecker holes, but this bird also uses natural cavities. Nests have been reported in oak, sycamore, and pine trees. In Monterey County, California, nests were found from 5 to 40 feet above ground in pine stumps or trees (Bent 1949). This bluebird, like the eastern, also readily nests near humans in bird houses. Nest boxes should be 5 × 5 × 8 inches with a 1.5-inch entrance hole located 6 inches from the floor. Boxes should be placed 5 to 10 feet above ground near forest openings or meadows.

Food: Beal (Bent 1949) examined the contents of 217 stomachs and found 72 percent animal material (grasshoppers 21 percent, caterpillars 20 percent, useful beetles 9 percent, other beetles 16 percent, ants 5 percent, other hymenoptera 1 percent) and 28 percent vegetable material, mostly wild fruits, including elderberries, mistletoe berries, blackberries or raspberries, prunes, cherries, and a few weed seeds.

Mountain bluebird
_Sialia currucoides_
L 6″

Habitat: The mountain bluebird nests in nearly all timber types of the Rocky Mountain region, and is reported from 800 to 11,000 feet elevation in Idaho (Burleigh 1972). However, this species usually ranges from 7,000 to 11,000 feet in open forests or near forest edges.

Nest: The mountain bluebird usually nests in natural cavities or in old woodpecker holes but will also use man-made structures. Nests have been reported in fir and pinyon snags and aspen trees (Burleigh 1972, Bent 1949). We recorded six nests in the White Mountains of Arizona ranging from 12 to 35 feet above ground in ponderosa pine snags. Five of these were in abandoned woodpecker holes and one was in a natural cavity. Nest boxes should be similar to those for other bluebirds.

Food: This is probably the most insectivorous of the bluebirds. Studies indicate that nearly 92 percent of the diet is animal material, including miscellaneous beetles, weevils, ants, bees, wasps, cicadas, stinkbugs, negro bugs, assassin bugs, jassids, flies, caterpillars, grasshoppers, locusts, and crickets (Bent 1949). Vegetable items include currants, grapes, elderberries, sumac seeds, mistletoe berries, hackberry seeds, Virginia creeper seeds, and cedar berries.

Starling
_Sturnus vulgaris_
L 6″

Habitat: Starlings breed in various habitats that provide adequate nestling food (Troetschler 1976) but are perhaps most numerous in suburban and rural habitat where suitable nesting sites abound. Kalmbach (1928) noted that starlings prefer thickly settled agricultural areas and stated that “They are partial to human association....” During establishment in the United States, starlings first settled in lowland areas and are still abundant there (Small 1974, Royall 1966, Bent 1950). In a southeast Ontario test, starlings preferred old field habitat over five other habitats when sufficient nest sites were available (Gibo et al. 1976).

Nest: Cavities in trees, telephone poles, or fence posts, in drainpipes, mail boxes, or buildings, and in haystacks and cliffs have been used for nesting, as have burrows and open nests of other species (Kessel 1957, Bent 1950). Natural nest sites seem to be preferred over nest boxes (Planck 1967). Competition between starlings and native species for nesting cavities usually favors the starling, but most native species seem to breed in some habitats where starlings are not numerous.

Food: Analysis of contents of 2,750 starling stomachs taken in the northeastern states showed 57 percent animal materials such as insects, millipeds, spiders, molluscs, and a few crustaceans. Insects such as weevils, ground beetles, and plant-feeding scarabaeids such as May beetles were especially important. Of the 43 percent vegetable material, wild fruit was most important, but cultivated cherries, vegetable material, grain, and seeds of various sorts were also used (Kalmbach 1928). In other areas, grapes, blueberries, figs, and other fruit, truck crops, sprouting crops, and prepared livestock feed are eaten.

Crested myna
_Acridotheres cristatellus_
L 9″

Habitat: The crested myna is native to the plains and lowlands of cultivated southern China, and was introduced in Vancouver, B.C., Canada in the 1890’s. Although the myna has been reported in the states of Washington and Oregon, most of the population is in Greater Vancouver and Vancouver Island. Mynas are apparently dwellers of urban and nearby open field areas (Mackay and Hughes 1963).

Nest: In urban areas, mynas nest in almost any enclosed area, including bird boxes intended for other birds. In wooded areas, holes made by flickers and other woodpeckers seem to be preferred (Bent 1950).

Food: Scheffer and Cottam (1935) examined the contents of 117 adult myna stomachs and found 39 percent animal and 61 percent vegetable matter. Animal matter included flies, moths and caterpillars, wasps, bees, ants, bugs, beetles, grasshoppers, spiders, and earthworms. Vegetable matter included wild varieties of elderberries, cherries, blueberries, crowberries, snowberries, salmonberries, loganberries, and serviceberries. Fruits of cultivated cherries, strawberries, raspberries, and blackberries were also eaten, with some damage done to apples, pears, cabbages, and lettuce.

Prothonotary warbler
_Protonotaria citrea_
L 4¾″

Habitat: The prothonotary warbler is found south of Canada in the eastern deciduous forests of the United States. Other names for this warbler (golden swamp warbler and willow warbler) describe its preference for swamps and periodically flooded areas. The prothonotary often lives near running water with streamside willows (Pearson 1936).

Nest: Nests are almost always in stumps and snags either standing in or near water (Simpson 1969) and often leaning over the water (Pearson 1936). Downy woodpecker and chickadee holes ranging from 2 to 12 feet and averaging 5 feet above the ground are used most often (Pearson 1936). However, the warbler reportedly has a wide tolerance for the type of nesting cavities used. Prothonotaries occasionally even nest in bird boxes and near buildings (Forbush and May 1939).

Food: Prothonotary warblers are primarily insectivorous. They eat ants, spiders, beetles, mayflies, and their larvae. They also will eat the larvae of water insects. This warbler feeds on trunks and branches of trees, shrubs, and fallen logs. They will also perch on rank grasses and water plants and eat small molluscs (Bent 1953).

Lucy’s warbler
_Vermivora luciae_
L 4¼″

Habitat: This warbler inhabits mesquite woodlands and riparian vegetation with willows and cottonwoods from Nevada to the southwestern United States.

Nest: Nests of Lucy’s warblers are usually located in tree cavities or under loose bark in willows, cottonwoods and mesquite. Ironwood, palo verde, and catclaw have also been used for nest trees (Robbins et al. 1966, Bent 1953, Peterson 1961).

Food: Insects are the major food items in the diet of Lucy’s warbler (Bent 1953).

House sparrow
_Passer domesticus_
L 5¼″

Habitat: House sparrows are well known associates of man, thriving in towns and urban situations. They are also birds of the suburban-rural landscape (Summers-Smith 1963). Optimum habitat requirements are perhaps best met around buildings where waste grain from poultry and livestock feeding can be found. The species is scarce or absent from densely forested and desert regions uninhabited by man (Kalmbach 1940).

Nest: House sparrows nest in eaves, crevices, and holes in buildings; in vines and creepers on walls; in the branches of trees; in nest boxes and natural cavities in trees; and in other assorted locations, perhaps in that order of importance. Open tree nests may be built more often in warmer latitudes, but females seem to prefer hole nests (Cink 1976). Nesting cavities of cliff and bank swallows and house finches may be usurped. Nests are usually at least 6 to 8 feet from the ground, may be as high as 50 feet, and groups or colonies are not uncommon. Nests are domed whether in cavities or the open. House sparrows all too readily accept bird houses erected for purple martins, bluebirds, and other species.

Food: Kalmbach’s (1940) study of the contents of 4,848 stomachs of suburban-rural birds indicated that adult and juvenile (non-nestling) house sparrows take 3.4 percent animal material throughout the year, particularly dung beetles, May beetles, and other Scarabaeidae. Grain from poultry yards, etc., made up the largest percentage of vegetable material (31.5 to 84.2 percent), followed by seeds of grasses and weeds (17 percent), and oats other than that in feed (14.4 percent). Ragweed, crabgrass, smartweed, and pigweed were important plants in the grass and weed category.

European tree sparrow
_Passer montanus_
L 5″

Habitat: The European tree sparrow was introduced in St. Louis, Missouri, in 1870. Coincident with the increase in house sparrows, European tree sparrows left the thickly settled parts of St. Louis and established populations throughout the city outskirts, suburban areas, farmyards, and woodlots. The species now occupies approximately 8,500 square miles in extreme east-central Missouri and west-central Illinois. They appear to be slowly expanding their range northward in western Illinois (Barlow 1973).

Nest: European tree sparrows nest in natural cavities, crevices, and woodpecker holes. They appear to be a weak competitor for available nesting sites. Part of the reason for the extension of tree sparrow range north may be related to large numbers of dead and dying American elms (victims of Dutch elm disease) which have provided an increasing source of nesting sites (Barlow 1973).

Food: Tree sparrows feed primarily on the ground on weed seeds, maize, insects, and spiders.

Literature Cited