スナヒバリ 対 ウロコスナヒバリ

The most reliable field mark between Desert Lark and Dunn's Lark is the tail pattern: Dunn's Lark shows a short, broad tail with a distinctive black underside and black upper surface with rusty-brown central feathers and pale outer feathers, while Desert Lark lacks a sharply defined black tail band and instead may show only a diffuse dark patch. Dunn's Lark is smaller and stockier, with a shorter tail and a more marked facial pattern, whereas Desert Lark is larger, longer-tailed, and more variable in overall color. Both species can be pale and streaked, but Desert Lark tends to be more streaked below and less sharply marked on the face. In flight, focus on tail pattern and structure; perched, check for facial markings and bill size.

1. Tail pattern in flight (all ages): Dunn's Lark shows a short, broad tail with a black underside and a black upper surface with rusty-brown central feathers and pale outer feathers. Desert Lark lacks a sharply defined black tail band, showing at most a diffuse dark patch.
2. Tail length and shape: Desert Lark has a noticeably longer tail, contributing to a more elongated appearance. Dunn's Lark's tail is short and broad, often appearing stubby in flight or when perched.
3. Facial pattern: Dunn's Lark has a strong pale supercilium, pale eyering, dark moustachial and malar stripes, and a dark mark under the eye, giving a sharply marked face. Desert Lark's face is plainer, lacking these strong contrasts.
4. Bill structure: Both have large bills, but Desert Lark's is longer and broader, matching its larger head and body. Dunn's Lark's bill is large, heavy, and pale pinkish or yellowish, but the overall impression is of a shorter, stubbier bird.
5. Underpart streaking: Desert Lark is more heavily streaked below, especially on the breast and flanks, while Dunn's Lark has only some dark streaks on the breast and is otherwise whitish below.
6. Upperpart color: Both can be pale sandy-brown, but Desert Lark is more variable (from pale to dark greyish-brown, sometimes with rufous in wings/tail). Dunn's Lark is consistently pale sandy-brown with darker streaks.
7. Plumage variability: Desert Lark is highly variable in color, often matching the substrate (sandy, rocky, or basaltic). Dunn's Lark is less variable, always pale sandy-brown.
8. Size and jizz: Desert Lark is larger (16–17 cm), longer-tailed, and longer-billed, with a big-headed look. Dunn's Lark is smaller (14–15 cm), stockier, and shorter-tailed.
9. Song: Desert Lark's song is mournful and mellow, while Dunn's Lark's is scratchy and whistled. Dunn's Lark often sings while hovering high above the ground.
10. Flocking and movement: Dunn's Lark is more likely to be seen in flocks outside the breeding season and may move nomadically after rain. Desert Lark is usually seen singly or in pairs.
11. Habitat context: Desert Lark is widespread in deserts and semi-deserts, often in rocky or variable terrain. Dunn's Lark is restricted to the Sahara and is more strictly a desert specialist.
12. After molt (Dunn's Lark): Dunn's Lark becomes duller and less marked after molt, but the tail pattern remains a reliable mark.
13. Legs: Desert Lark has stouter legs, but this is subtle and best used as a supporting mark.
14. Perched vs. flight views: In flight, focus on tail pattern and structure. When perched, check for facial markings and overall size/shape.
15. Pitfalls: Both can appear pale and streaked, especially in worn plumage or strong light. Always confirm with tail pattern and facial markings when possible.

Desert Lark is noticeably larger, measuring 16–17 cm in length, while Dunn's Lark is smaller at 14–15 cm. Dunn's Lark also has a shorter, broader tail and a more compact, stocky build compared to the longer-tailed, longer-billed Desert Lark. The wingspan of Dunn's Lark (25–30 cm) is not directly compared in the notes, but Desert Lark is described as longer overall and with stouter legs. Use overall size and tail length as supporting marks, especially when birds are seen side by side.

• Juvenile/immature/first-winter (flight views): No unique upperwing or flight marks are described for either species at these ages, so focus remains on tail and overall structure.
• Adult plumage: Desert Lark is highly variable, ranging from pale to dark, but generally shows pale greyish-brown upperparts, pale pinkish-grey underparts with more extensive streaking, and lacks a sharply defined black tail band (may show a diffuse dark patch instead). Dunn's Lark is pale sandy-brown above with darker streaks, whitish below with some breast streaking, and has a distinctive facial pattern: pale supercilium, pale eyering, dark moustachial/malar stripes, and a dark mark under the eye. Its tail is short and broad, black below, black above with rusty-brown central feathers and pale outer feathers. After molt, Dunn's Lark becomes duller and less marked, but the tail pattern remains distinctive. Desert Lark can show some rufous in the wings and tail, but never the sharply bicolored tail of Dunn's Lark.

Both species feed on the ground, but Dunn's Lark is more likely to be seen in flocks outside the breeding season and exhibits nomadic movements in response to rainfall. Dunn's Lark males may sing from the ground or hover high above it (30 meters or more), while Desert Lark sings from the ground, a boulder, or during undulating flight. Both species dig for food with their bills, but Dunn's Lark's flocking and nomadism may be a clue in context.

Desert Lark occupies a very wide range of deserts and semi-deserts from Morocco to western India, adapting its plumage color to match local substrates (sandy, rocky, or basaltic). Dunn's Lark is restricted to parts of the Sahara from Mauritania to central Sudan and is more strictly a desert specialist. Both occur in arid, open habitats, but Desert Lark's range is much broader and it is more likely to be encountered in rocky or variable desert terrain.

Desert Lark's song is a mournful, mellow 'choo-wee-chacha wooee,' less squeaky than Bar-tailed Lark, and its flight call is a short 'churree' or 'chee-lu.' Dunn's Lark gives a scratchy warbling song with short whistling phrases, often delivered while hovering high above the ground. The difference in song quality and delivery (mournful and mellow from Desert Lark, scratchy and whistled from Dunn's Lark) can help in good conditions, but both species sing from the ground or in flight.