Zone-tailed Hawk vs Rough-legged Buzzard

In short

The most reliable field mark to separate Zone-tailed Hawk from Rough-legged Buzzard is the tail and underwing pattern in flight, especially in immatures: Zone-tailed Hawk (all ages) shows a strikingly banded tail with a broad pale band second from the tip and mostly dark underwings with paler flight feathers, while Rough-legged Buzzard (especially light morphs and juveniles) shows a mostly white tail with a single dark subterminal band and a bold dark carpal patch on the underwing. Zone-tailed Hawk is overall blackish and closely mimics Turkey Vulture in flight style and silhouette, whereas Rough-legged Buzzard is bulkier, longer-winged, and variable in plumage but never as uniformly dark. If seen perched, note the feathered legs of Rough-legged Buzzard and the slimmer, longer-tailed look of Zone-tailed Hawk. Habitat and range are also strong clues: Zone-tailed is a bird of warm, dry Americas, while Rough-legged is strictly an Arctic breeder and a winter visitor to temperate regions.

Identification tips

1. Tail pattern in flight (all ages): Zone-tailed Hawk shows three or four pale tail bands, with the second from the tip broadest and most obvious; Rough-legged Buzzard has a mostly white tail with a single, bold dark subterminal band (sometimes more in juveniles), never multiple broad pale bands.
2. Underwing pattern (especially immatures): Rough-legged Buzzard (light morphs) shows a pale underwing with a bold, square dark carpal patch; Zone-tailed Hawk has dark underwings with paler, barred flight feathers but never a dark carpal patch.
3. Body color: Zone-tailed Hawk is overall blackish (adults and immatures), while Rough-legged Buzzard is brown and white, often with a broad brown chest band and much paler underparts.
4. Leg feathering: Perched Rough-legged Buzzard has feathered legs down to the toes (hence 'rough-legged'), while Zone-tailed Hawk has bare, yellow legs.
5. Flight style: Zone-tailed Hawk soars with wings in a shallow dihedral and rocks side to side, mimicking Turkey Vulture; Rough-legged Buzzard soars with flatter wings and often hovers (kites) over fields.
6. Wing shape: Rough-legged Buzzard has longer, broader wings with tips that can reach or extend past the tail when perched; Zone-tailed Hawk is more slender, with proportionally longer tail and less massive wings.
7. Face and cere: Zone-tailed Hawk has a light gray lore and yellow cere; Rough-legged Buzzard's face is less contrasting, with no bright cere.
8. Habitat and range: Zone-tailed Hawk is found in warm, dry, open country in the Americas; Rough-legged Buzzard is strictly a bird of the far north in summer and open temperate fields in winter—never in arid zones.
9. Plumage variability: Rough-legged Buzzard is highly variable (light and dark morphs), but even dark morphs show the carpal patch and white tail base; Zone-tailed Hawk is always dark with barred tail.
10. Size and build: Rough-legged Buzzard is bulkier and heavier; Zone-tailed Hawk is lighter and more slender for its length.
11. Mimicry context: If seen among Turkey Vultures, suspect Zone-tailed Hawk; Rough-legged Buzzard does not associate with vultures.
12. Perched jizz: Zone-tailed Hawk is slim, long-tailed; Rough-legged Buzzard is chunkier, with a large head and feathered legs.
13. Seasonal context: In North America, Rough-legged Buzzard is only present in winter; Zone-tailed Hawk is resident or migratory in the south and west.
14. Juvenile marks: Immature Zone-taileds have small white breast spots and a tail with narrow bands and broad dark tip; juvenile Rough-leggeds have more white below and a single dark tail band.
15. Common pitfalls: Dark morph Rough-leggeds are rare and never as uniformly black as Zone-tailed; Zone-tailed never shows a pale underwing with a dark carpal patch or mostly white tail.

Size

Rough-legged Buzzard is the heavier and slightly larger species, with an average body mass of about 926 g compared to Zone-tailed Hawk's 763 g. Both are similar in length (46–56 cm for Zone-tailed, 46–68 cm for Rough-legged) and wingspan (Zone-tailed: 117–140 cm, Rough-legged: 120–153 cm), but Rough-legged Buzzard is bulkier and has longer wings relative to its body. Zone-tailed Hawk is more slender and lighter for its size, especially compared to the robust, broad-winged impression of Rough-legged Buzzard.

Plumage

Juvenile and immature plumages are most diagnostic in flight: Zone-tailed Hawk (immature) has a dark body with small white spots on the breast, and a tail with narrow gray/black bands and a broad dark tip; adults show three or four pale tail bands, with the second from the tip being broad and conspicuous. The underwings are mostly dark with lighter gray barring on the flight feathers, giving a silvery impression at distance. Rough-legged Buzzard (especially light morphs and juveniles) has a mostly white tail with one or more dark subterminal bands, and the underwing is pale with a bold, square dark carpal (wrist) patch. The chest often shows a broad brown band, and the body is generally brown and white, sometimes heavily speckled. Dark morph Rough-leggeds are much less common but still show the carpal patch and white tail base. Zone-tailed never shows a pale underwing with a dark carpal patch or a mostly white tail. In perched birds, Rough-legged's feathered legs are unique among Buteos in its range, while Zone-tailed's legs are bare and yellow.

Behaviour

Zone-tailed Hawk is famous for its mimicry of Turkey Vulture: it soars with wings held in a dihedral and rocks side to side, often joining vulture kettles. This behavior is unique among Buteos and is used to approach prey by deception. Rough-legged Buzzard, in contrast, often hovers (kiting) over open ground while hunting, a behavior rare in Zone-tailed. In flight, Rough-legged appears more eagle-like, with longer, broader wings and a slower, steadier flight style, rarely showing the vulture-like rocking of Zone-tailed.

Habitat

Zone-tailed Hawk is a bird of warm, dry, open habitats in the Americas—arid foothills, canyons, and scrubby deserts. Rough-legged Buzzard breeds in Arctic and subarctic tundra and taiga, and winters in open temperate country such as fields, marshes, and prairies, but never in hot, arid zones. Their ranges do not overlap in breeding season, and only rarely in winter in the southern US, so context and location are strong clues.