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DIURNAL RAPTORS (51+ SPECIES) Popular, widespread assemblage of predatory

birds, comprising 3 families: Hawks (Accipitridae; including harriers, kites, eagles), Falcons

(Falconidae; including caracaras), and Ospreys (Pandionidae; sometimes merged into hawks).

Range from dainty American Kestrel to huge Harpy Eagle. Genetic studies indicate that falcons

share a common ancestor with parrots, but traditionally they have been grouped with hawks as

birds of prey, as done here for ID purposes.

Ages differ, sexes different or similar (females larger, strikingly so in some species); adult

appearance attained in 1–2 years for falcons and medium-size to large hawks, up to 4–5 years

for eagles. ID of some raptors straightforward but others can be challenging, compounded by

age variation and highly variable plumages. Appreciation of behavior, habitat, and structure

(wing shape on flying birds, relative wing and tail lengths on perched birds, head and bill size)

often more helpful than colors and patterns, although those should always be noted.

NORTHERN MIGRANT ACCIPTERS

(2 species). Mostly favor forest habitats; seen

infrequently except when migrating. Relatively short wings and long tails good for maneuvering among

trees, where mostly hunt birds. Soar readily, mainly in mid–late morning and during migration, when may

associate loosely with large movements of other raptors. Tropical forest resident accipiters are on p. 128.

SHARP-SHINNED HAWK  Accipiter striatus 28–36cm, WS 51–64cm. Un­

common winter migrant to varied wooded and forested habitats, mainly in

foothills and highlands. Flies with bursts of quick flapping and short glides;

soars mainly in migration. Hunts from cover and rarely perches in open situ­

ations. Note small size, quick snappy wingbeats, relatively short rounded wings,

long tail with overall squared tail tip, thin legs. Main confusion is with larger

Cooper’s Hawk, which has larger head, longer wings, longer and rounded tail

with bolder white tip, adult often appears more capped; in flight, Cooper’s

holds wings out straighter, accentuating big head, not pushed forward like

small-headed Sharp-shinned. Also cf. Tiny Hawk (p. 128), Double-toothed Kite (p. 132). Usually silent

in winter. STATUS: Uncommon Oct–Mar on Pacific slope and in highlands, mainly 500–2500m; more

widespread during migration, Oct–Nov, Mar–Apr, when rare in Caribbean lowlands. (Breeds N America

to Mexico, winters to Panama.)

COOPER’S HAWK  Accipiter cooperi 38–44cm male, 44–51cm female, WS

68–86cm. Scarce winter migrant to varied wooded, forested, and adjacent semi-

open habitats, mainly in foothills and highlands. Flies with strong, fairly quick

stiff wingbeats, brief glides; soars on flattish wings. Hunts mainly from cover but

perches in open and semi-open situations, on fence posts, utility poles. Female

appreciably bigger than male, can be mistaken for Gray or Gray-lined Hawks;

male easily confused with smaller Sharp-shinned Hawk (which see). Also cf.

adult Double-toothed Kite (p. 132). Usually silent in winter. STATUS: Scarce

Oct–Mar on n. Pacific slope and in highlands, mainly 1000–3000m; more

widespread during migration, Oct–Nov, Mar–Apr, when very rare in Caribbean lowlands. (Breeds N

America to Mexico, winters to Costa Rica.)

NORTHERN HARRIER  Circus hudsonius 46–56cm, WS 99–117cm. Scarce

winter migrant to open country, especially marshes. Note white rump and

broad dark trailing edge to secondaries in all plumages, rather owl-like facial

discs, and habits. Often seen in flight, quartering and sailing low over marshes,

grassland, other open habitats; perches on ground and fence posts. Flies with

buoyant and smooth wingbeats and glides easily, wings held in a shallow V.

During migration can be disconcertingly high overhead, best identified by long

narrow wings and long tail, buoyant flight; cf. Swainson’s Hawk. Male has gray

head and upperparts, sparse rusty barring on belly, black wing-tips; female

brownish overall, heavily streaked below; 1st-year has mostly unstreaked rusty underparts, often fading to

buff by spring. Usually silent in winter. STATUS: Rare to uncommon Oct–Apr on both slopes to 1500m,

mainly in nw. lowlands. (Breeds N America, winters to n. S America.)