Yellow-bellied Flycatcher (Empidon ax floviventris) A.O.U. No. 463.0 Range RANGE: Breeding: Newfoundland, w. to s. Mackenzie district, Northwest Territories, s. to n. New England, n. Pennsylvania (rarely) and c. Alberta. Winter: Mexico and Central America. RELATIVE ABUNDANCEIN NEW ENGLAND:Common (Maine). HABITAT: Breeding: Coniferous forests; low, wet, swampy thickets bordering ponds, streams and bogs, spruce and alder swamps, cool moist mountainsides. SPECIALHABITAT REQUIREMENTS: Coniferous forests, low wet areas. NESTING: Egg dates: June 10 to June 27, New York (Bull 1974:371).Clutch size: 3 to 5, typically 3 or 4 (Harrison 1975: 121). Incubation period: 15 days. Nestling period: 13 days. Age at sexual maturity: 1 year. Nest site: On or near the ground, sometimes at the base of a tree in a cav- ity formed by roots, but more often beside a hummock or moundand well hidden in sphagnum moss or other vege- tation. FORAGING:Major foods: Flying insects, fruits (occasion- ally). Substrate: Air. Technique: Hawking. COMMENTS:Birds perch and feed close to ground. Food habit studies indicate a predominance of animal food (97 percent) over vegetable food (3 percent) (Beal 1912 in Bent 1942: 178). KEYREFERENCES: Bent 1942, Walkinshaw 1957. Acadian Flycatcher (Empidonax virescens) A.O.U. No. 465.0 Range RANGE:Breeding: Most of e. North America, including ne. Pennsylvania, sw. and se. New York and casually to s. New England. Winter: Costa Rica to n. South Amer- ica. RELATIVEABUNDANCE IN NEW ENGLAND:Common. HABITAT:Breeding: Deciduous woodlands, shaded ra- vines, heavily wooded bottomlands, river swamps, ham- mocks of cypress ponds (Harrison 1975: 122). NESTING:Egg dates: April to July. Clutch size: Usually 2 to 4. Incubation period: 13 to 14 days. Nestling period: 13 to 15 days (Newman 1958). Broods per year: 1. Age at sexual maturity: 1. Nest height: 8 to 20 feet (2.4 to 6 m). NEST SITE:Usually suspended in hammock-like structure from the fork of a branch frequently near water (Godfrey 1979:255). Nests are often far out from the truck and shaded (Harrison 1975: 122). FORAGING:Major foods: Moths, caterpillars, beetles, wasps, bees, and some wild berries (Terres 1980:381). Substrate: Air. Technique: Sallier. KEY REFERENCES:Godfrey 1979, Harrison 1975, Mum- ford 1964. Alder Flycatcher (Empidonax alnoruml A.O.U. No. 466.3 Range RANGE: Breeding: Newfoundland, w. to Alaska, s. to e. and n. Pennsylvania, c. Minnesota and c. British Colum- bia. Winter: Central and South America. RELATIVE ABUNDANCEIN NEW ENGLAND:Common (Maine)to uncommon (s. New England). HABITAT:Breeding: Low, damp thickets bordering bogs, swamps and marshes. Often in alders, willows, elders, sumacs, viburnums. Prefers open areas. SPECIALHABITAT REQUIREMENTS: Areas with dense, low shrubs and clearings (edges). NESTING: Egg dates: June 11 to July 29, New York (Bull 1974:376).Clutchsize: 3 to4. Incubation period: 12 to 14 days. Nestling period: 13 to 16 days. Broods per year: 1. Age at sexual maturity: 1 year. Nest height: 1 to 6 feet (0.3 to 1.8 m), typically 3 to 4 feet (0.9 to 1.2 m). Nest site: In low tree or shrub saddled on a branch or in an upright fork. TERRITORYSIZE: Singing males of three separate popula- tions had average territory sizes of 3.2, 3.8, 7.7 acres (1.2, 1.5, 3.1 ha) (Stein 1958). FORAGING:Major foods: Flying insects. Substrate: Air. Techniques: Hawking, flight gleaning. KEYREFERENCES: Bent 1942, King 1955, Stein 1958. Willow Flycatcher (Empidonax traillii) A.O.U. No. 466.4 Range RANGE:Breeding: Southern Main, w. to British Colum- FORAGING:Major foods: Flying insects. Substrate: Air. bia, s. to n. Virginia, c. Arkansas and s. New Mexico. Techniques: Hawking, flight gleaning. Winter: Central and South America. COMMENTS:Difficult to distinguish from Alder Fly- RELATIVEABUNDANCE IN NEW ENGLAND: Uncommon. catcher (both formerly Traill's) even when in hand. Most widely accepted diaqnostic characteristic is voice differ- HABITAT:Breeding: Prefers open, newly clearcut areas, ence: Willow - "fiti-bew", Alder - "fee-bee-0". damp to dry brushy fields, woodland edges, hedgerows, roadsides, and orchards. Frequents uplands and low- KEY REFERENCES:Graber et al. 1974, King 1955, Stein lands. 1958, Walkinshaw 196613. SPECIALHABITAT REQUIREMENTS: Low trees and shrubs with clearings (edges). NESTING:Egg dates: June 11 to July 29, New York (Bull 1974:376). Clutch size: 3 to 5, typically 3 or 4. Incubation period: 12 to 15 days. Nestling period: 15 to 18 days. Broods per year: 1. Age at sexual maturity: 1 year. Nest height: 3 to 25 feet (1.O to 7.6 m). Typically 4 to 6 feet (1.2 to 1.8 m). Nest site: In a fork or saddled on a horizontal limb of a shrub, commonly willow, elder, viburnum, hawthorn, and others. TERRITORYSIZE: 0.8 to 2.9 acres (0.3 to 1.2 ha) (average 1.74 acres (0.7 ha) for 73 territories in a dry marsh in Michigan (Walkinshaw 1966b). Singing males of three separate populations had average territory sizes of 2.6, 3.2, and 4.5 acres (1.1, 1.3, and 1.8 ha) (Stein 1958). SAMPLEDENSITIES: 35 to 30 pairs per square mile (10 to 11 pairs/km2)in willow clump habitat in Illinois (8to 9 birds per 100 acres (40 ha)) (Ford 1956 in Graber et al. 1974). Least Flycatcher (Empidonax minim us) A.O.U. No. 467.0 Range RANGE:Breeding: Nova Scotia to Mackenzie district, SAMPLEDENSITIES: 2 nests per 27.67 acres ( 1 1.2 ha) of Northwest territories, s. to Long Island and central New residential woodland in Illinois (Beecher 1942 in Graber Jersey and the mountains of Georgia, w. to Wyoming et al. 1974). 9 nests per 19 acres (7.7 ha) in Virginia and British Columbia. Winter: Mexico and Central (Davis 1959) - oak-chestnut woodland. 2.7 pairs per America. acre (0.4 ha) in aspen-birch-maple habitat in Michigan (MacQueen 1950). RELATIVEABUNDANCE IN NEW ENGLAND: Common. FORAGING:Major foods: Flying insects. Substrate: Air. HABITAT:Breeding: Deciduous forest edges, burns and Techniques: Hawking, flight-gleaning, gleaning. clearings, open shrublands, orchards, well-planted resi- dential areas, edges of country roads, overgrown pas- COMMENTS:Food studies have shown that Least Fly- tures and open deciduous woodlands. catchers eat 98 percent animal and 2 percent vegetable material in summer (Beal 1912 in Bent 1942:218). SPECIALHABITAT REQUIREMENTS: Open deciduous forest, edge (shade for nest and open space for feeding), mod- KEYREFERENCES: Bent 1942, Breckenridge 1956, Graber erately vegetated woodlands (intermediate openness in et al. 1974, MacQueen 1950. understory) (Breckenridge 1956). NESTING:Egg dates: May 16 to July 28. New York (Bull 1974:377).Clutch size: 3 to6, typically 3 or 4. Incubation period: About 14 days. Nestling period: 14 to 16 days. Broods per year: 1 or 2. Age at sexual maturity: 1 year. Nest height: 2 to 60 feet (0.6 to 18.3 m), typically 10 to 20 feet (3.0 to 6.1 m). Nest site: In crotch or on limb of decid- uous or coniferous tree. Known to nest in apple, oak, pine, willow, sugar maple, and others. TERRITORYSIZE: 0.35 to 0.55 acre (0.1 to 0.2 ha) in oak- chestnut woodland in Virginia (Davis 1959). 0.03 to 0.5 acre (0.01 to 0.2 ha) (average 0.18 acre (0.07 ha)) in Michigan for 33 territories (MacQueen 1950). Usually less than I acre (0.4 ha) (Breckenridge 1956). Eastern Phoebe (Sayornis phoebe) A.O.U. No. 456.0 Ranae RANGE: Breeding: Nova Scotia, w. to Alaska, s. to n. 100 ac:es (40 ha) in mixed agricultural habitats in Mary- Georgia (mountains) and e. New Mexico. Winter: Mary- land. 0.6 pairs per I00 acres (40 ha) in mixed forests and land s. Rarely to s. New England (coast)and Long Island. fields in Maryland (Stewart and Robbins 1958:201). RELATIVEABUNDANCE IN NEW ENGLAND:Common. FORAGING:Major foods: Flying insects, occasionally small fruits. Substrate: Air. Technique: Hawking. HABITAT:Breeding: Woodland cliffs, ravines, agri- cultural and suburban areas, often near streams. COMMENTS:Phoebes usually choose one or more favorite perches from which to hawk insects. They are common SPECIALHABITAT REQUIREMENTS: Perches 5 to 15 feet (1.5 victims of cowbird parasitism. Blocher (1936) reported to 4.6 m) high. Cliffs or ledges at stream-side clearings or parasitism in 50 percent of the nests observed in Illinois. man-made structures at forest openings (Hespenheide This species benefits from forest cuttings, moving into 1971). areas where cuttings have exposed ledge and rocks and creating sunny forest openings in the vicinity of ledge, NESTING: Egg dates: April 20 to August 4, New York (Bull 1974:369). Clutch size: 3 to 8, typically 5. Incubation KEY REFERENCES: Bent 1942, Graber et al. 1974, Hes- period: 15 to 17 days. Nestling period: 15 to 17 days. penheide 197 1. Broods per year: 2. Age at sexual maturity: 1 year. Nest height: 2.5 to 20 feet (0.8 to 6.1 m), typically less than 15 feet (4.6 m). Nest site: On a ledge, usually sheltered above by an overhang, often under leaves or on window ledges, barn beams, bridge girders. Nest is frequently near water. Birds are very adaptable in nesting habits. TERRITORYSIZE: 3.3 to 7.1 acres (1.3 and 2.9 ha) for 2 pairs nesting on buildings in Kansas (Fitch 1958). 0.7 acre (0.3ha) in an Illinois floodplain forest (Fawver 1947 in Graber et al. 1974). SAMPLEDENSITIES: 6 nests per 30 acres (12.1 ha) in opti- mum habitat in Illinois (Graber et al. 1974). 7 pairs per Great Crested Flycatcher (Myiarchus crinitus) A.O.U.