オビオミドリカザリドリ 対 キムネミドリカザリドリ

要点

The most reliable field mark to separate Band-tailed Fruiteater from Golden-breasted Fruiteater is the presence of a distinct black band near the tip of the tail in Band-tailed (all ages), which Golden-breasted completely lacks. Adult male Band-tailed also shows a black head and upper breast with a thin yellow collar, while Golden-breasted males have a green head and a bright yellow throat and breast. Females are trickier: Band-tailed females have a green head and yellow underparts with black scalloping, whereas Golden-breasted females are green below with yellow streaks. Both species have white-tipped tertials, but the tail pattern and underpart coloration are the best clues. Range is a strong context clue: Band-tailed occurs in Peru and Bolivia, Golden-breasted in Colombia and Venezuela.

識別のコツ

1. Tail pattern (all ages): Band-tailed Fruiteater always shows a distinct black band near the tip of the tail with white tips to the tail feathers. Golden-breasted Fruiteater's tail is plain green with no black band or white tips. This is the single most reliable field mark, especially in flight or when the tail is fanned.
2. Adult male head and breast: Band-tailed male has an entirely black head and upper breast with a thin yellow collar (except on the nape). Golden-breasted male has a green head and a bright yellow throat and breast, with no black or collar.
3. Female underparts: Female Band-tailed has yellow underparts with black scalloping, while female Golden-breasted is green below with yellow streaks. This can be subtle, but the presence of yellow with black marks (Band-tailed) versus green with yellow streaks (Golden-breasted) is helpful.
4. Flank color: Band-tailed (both sexes) has green flanks with black scalloping; Golden-breasted male has green flanks blending into the yellow breast, and female is green with yellow streaks.
5. Yellow collar: Band-tailed male (especially subspecies signata) shows a thin to bold yellow collar at the base of the black head and upper breast, absent in Golden-breasted except for a yellow neck band in some subspecies (P. a. decora), but this is on the sides, not a full collar.
6. Tertial tips: Both species have white-tipped tertials, so this is not a separator.
7. Bill and iris color: Band-tailed has a crimson bill (sometimes with a black culmen) and brown iris; Golden-breasted has an orange or orange-red bill and orange-yellow iris. These are subtle and not always visible in the field.
8. Leg color: Band-tailed has red or orange-red legs and feet; Golden-breasted has greenish gray legs and feet. Again, subtle and not always visible.
9. Size: Band-tailed is slightly larger and bulkier, but the difference is minor and should not be used as a primary field mark.
10. Range: Band-tailed occurs in Peru and Bolivia; Golden-breasted is found only in Colombia and Venezuela. If you know your location, this is a strong separator.
11. Habitat: Both inhabit humid montane forests, so habitat alone is not diagnostic unless paired with range.
12. Behavior: Golden-breasted is more likely to join mixed-species flocks; Band-tailed is not specifically noted for this, but behavior is not a strong separator.
13. Voice: Only Band-tailed's song is described; if you hear a series of very high notes followed by a thin, descending whistle, it may indicate Band-tailed, but absence of vocalization is not helpful.
14. Subspecies variation: Be aware that Band-tailed subspecies signata can have a much bolder yellow collar and less black on the underparts, while Golden-breasted subspecies decora and festiva can show more yellow on the neck or underparts, potentially confusing the picture. Always check the tail pattern for confirmation.
15. Quiz pitfalls: Immature or female birds in flight may be especially confusing. Focus on the tail pattern (black band and white tips for Band-tailed, plain green for Golden-breasted) and underpart coloration (scalloped yellow for Band-tailed, streaked green/yellow for Golden-breasted) for the best chance at a correct ID.

大きさ

Band-tailed Fruiteater is slightly larger, measuring 18.5–19.5 cm in length and weighing about 50 g, while Golden-breasted Fruiteater is 16.5–17.5 cm long and weighs 46–50 g. The difference is subtle in the field, but Band-tailed generally appears a bit bulkier and longer-tailed, especially when perched. Both are compact, short-tailed cotingas, but the size gap is minor and best used as a supporting clue.

羽色

For all ages and sexes, Band-tailed Fruiteater shows a diagnostic black band near the tip of the tail, with white tips to the tail feathers; Golden-breasted Fruiteater's tail is plain green with no black band or white tips. On the wing, both species have white-tipped tertials, so this is not a separator. Adult male Band-tailed has a striking black head and upper breast with a thin yellow collar (except on the nape), green upperparts, and yellow underparts with black scalloping; Golden-breasted male has a green head and upperparts, a bright yellow throat and breast, and green flanks that blend into the yellow. Female Band-tailed is green-headed with yellow underparts and black scalloping, while female Golden-breasted is green below with yellow streaks. Subspecies variation exists: some Band-tailed (P. i. signata) have a bolder yellow collar and less black on the underparts, while some Golden-breasted subspecies show a yellow neck band (P. a. decora) or more yellow below (P. a. festiva).

行動

Both species are primarily frugivorous and forage in the mid-levels of montane forest, often in pairs. Golden-breasted Fruiteater is noted for joining mixed-species flocks, while Band-tailed is not specifically mentioned doing so. Both are generally unobtrusive and perch quietly, but behavior is not a strong separator.

生息環境

Band-tailed Fruiteater is found in humid montane forests on the eastern slopes of the Andes in Peru and Bolivia, at elevations mostly between 1,500 and 3,000 m. Golden-breasted Fruiteater inhabits similar montane forests but is restricted to Colombia and Venezuela, generally at similar elevations. There is no range overlap: location is a strong separator.

声

Band-tailed Fruiteater's song is a series of very high notes followed by a thin, descending whistle ("ti-ti-ti teeeeeeew") and its call is a series of high "ti" or "tswee" notes. No detailed vocal description is available for Golden-breasted Fruiteater, so voice is not a reliable separator.