Long-crested Pygmy-Tyrant vs Acre Tody-Tyrant

In short

The most reliable field mark to separate Long-crested Pygmy-Tyrant from Acre Tody-Tyrant is the presence of a long, black, often-erect crest on the former, which is entirely absent in the latter. In all ages and plumages, Long-crested Pygmy-Tyrant shows a distinctive black crest with gray edges that extends well beyond the rear of the head, while Acre Tody-Tyrant has a plain, greenish olive crown with only faint dark streaks. When perched, check for the pygmy-tyrant’s whitish, streaked underparts and weak wing bars versus the tody-tyrant’s olive-green, mostly unstreaked belly and more prominent yellowish-tawny wing bars. In flight or at rest, the Acre Tody-Tyrant’s wings show blackish feathers with yellow and whitish edges, creating a crisper pattern than the duller, olive-tipped wings of the pygmy-tyrant. Bill shape and iris color also differ, but the crest is the fastest and most reliable field mark.

Identification tips

1. Crest presence: Long-crested Pygmy-Tyrant always has a long, black, gray-edged crest that is often raised and extends beyond the back of the head. Acre Tody-Tyrant never shows a crest—its crown is smooth with only faint dark streaking. This is the quickest and most reliable field mark in any posture or age.
2. Crown and face color: The pygmy-tyrant has black crown feathers with gray edges and whitish lores on an olive face. The tody-tyrant’s head is greenish olive with darker streaks, and the lores and face are washed tawny, not whitish.
3. Wing bars: The pygmy-tyrant’s wing bars are weak, formed by olive tips to dusky coverts and often barely visible. The tody-tyrant has two crisp wing bars from yellowish-tawny edges to blackish coverts—much more conspicuous in the field.
4. Wing pattern in flight/perched: Acre Tody-Tyrant’s blackish wings have yellow outer and whitish inner edges on the flight feathers, creating a more patterned look. The pygmy-tyrant’s wings are dusky with only olive tips, lacking strong contrast.
5. Underparts: The pygmy-tyrant is whitish below with gray streaks throughout. The tody-tyrant is olive-green on the throat and breast with creamy yellowish streaks, but the belly and undertail are bright sulphur-yellow and unstreaked—look for the color break.
6. Tail color: Both have dusky or blackish tails, but the tody-tyrant’s tail feathers have dark green inner vanes, which may show as a subtle greenish cast; this is subtle and not always visible.
7. Iris color: The pygmy-tyrant has a whitish yellow iris, while the tody-tyrant’s is cream to brownish hazel. This can be hard to see unless close.
8. Bill shape and color: The pygmy-tyrant’s bill is gray and more typical of small tyrants. The tody-tyrant’s is flatter, with a wide base and large oval nostrils, black with a creamy base to the mandible—noticeable if seen well from below or in profile.
9. Leg color: The pygmy-tyrant has dull pinkish legs and feet; the tody-tyrant’s are gray. This is subtle and rarely diagnostic in the field.
10. Size and structure: The tody-tyrant is slightly larger and heavier (about 1 cm longer and 2 g heavier on average), but this is not a strong field mark unless both are seen side by side.
11. Voice: If you hear a short, low-pitched trill of 'tick' notes, it is Acre Tody-Tyrant. Absence of this song is not diagnostic, as the pygmy-tyrant’s voice is undescribed.
12. Sex and age: Both species are sexually monomorphic in plumage, and no age-specific marks are described, so all field marks above apply to adults and presumed immatures.
13. Habitat and range: Both species overlap widely in the western Amazon and use similar forest habitats—do not rely on location or habitat alone for separation.
14. Behavior: Both are active, midstory foragers, but the pygmy-tyrant may be more animated when raising its crest.
15. Pitfalls: The main confusion arises when the pygmy-tyrant’s crest is flattened or not visible, making it resemble the tody-tyrant. In these cases, focus on wing bar strength, underpart streaking, and facial coloration.

Size

Both species are tiny Amazonian tyrant-flycatchers, but the Acre Tody-Tyrant is slightly larger and heavier: it averages about 11 cm in length and 9 g in mass (one measured male), while the Long-crested Pygmy-Tyrant is 10–10.5 cm and about 7 g. This size difference is subtle in the field and not a strong separator, but the tody-tyrant may look a bit bulkier, especially in direct comparison.

Plumage

No age-specific wing or flight pattern is described for either species, so all contrasts apply to adults and presumed immatures. The Long-crested Pygmy-Tyrant is olive above with a long, black, gray-edged crest (often raised), whitish lores, and weak olive-tipped wing coverts forming faint wing bars. Its underparts are whitish with gray streaks throughout. The Acre Tody-Tyrant, in contrast, has a greenish olive head and nape with darker streaks (but no crest), tawny lores and facial wash, and blackish wings with yellow outer and whitish inner edges on the flight feathers. Its wing coverts are edged yellowish-tawny, producing two clear wing bars. The underparts are olive-green with creamy yellowish streaks on the throat and breast, but the belly and undertail are bright sulphur-yellow and largely unstreaked. The iris is whitish yellow in the pygmy-tyrant and cream to brownish hazel in the tody-tyrant. Bill color also differs: gray in the pygmy-tyrant, black with a creamy base to the mandible in the tody-tyrant.

Behaviour

Both species are small, active, and often forage in the midstory or lower canopy, but detailed behavioral differences are not described in the sources. Both may be encountered singly or in pairs, and neither is known for highly conspicuous behavior. The pygmy-tyrant may appear more animated when raising its crest.

Habitat

Both species occur in the western Amazon Basin of Bolivia, Brazil, and Peru, and both are found in similar forested habitats. Habitat is not a reliable separator between these two in their overlapping range.

Voice

Only the Acre Tody-Tyrant’s voice is described: its song is a short, low-pitched trill of 'tick' notes, lacking introductory notes, and it also gives single-note 'skep' or 'keek' calls, or lower 'kup' calls. No vocal description is available for Long-crested Pygmy-Tyrant, so voice is not a reliable separator unless the tody-tyrant’s distinctive trill is heard.