Crowned Woodnymph vs Azure-crowned Hummingbird

In short

To separate Crowned Woodnymph from Azure-crowned Hummingbird, focus first on the color and extent of the crown and underparts: adult male Crowned Woodnymphs show a striking violet (or green in some subspecies) crown and glittering green throat and chest, while Azure-crowned Hummingbirds have a bright metallic blue (or green) crown but always white underparts with bronze-green sides. Females and immatures are trickier, but the Woodnymph female is bright green above and pale gray below, whereas Azure-crowned females are bronze-green above and white below with bronze-green sides. Tail pattern and bill color also help: Woodnymph females have blue-black tails with white tips, while Azure-crowned Hummingbirds have bronze-green tails with whitish tips in immatures and a two-toned bill. Structure is similar, but Azure-crowned is slightly heavier. In the field, underpart color and crown hue are the most reliable marks, especially on perched birds.

Identification tips

1. Crown color (adult males): Crowned Woodnymph males have a violet (or glittering green in some subspecies) crown, while Azure-crowned males have a bright metallic blue (or green in S. c. chlorostephana) crown. The blue of Azure-crowned is usually more intense and sharply defined, whereas Woodnymph's violet may blend with the upper back.
2. Underpart color (all ages/sexes): Crowned Woodnymph males have a glittering green throat and chest, with violet belly (nominate), while Azure-crowned of both sexes always have white underparts with metallic bronze-green sides and duller bronze-green flanks. Female Woodnymphs are pale gray below, never white.
3. Back and rump (adults): Crowned Woodnymph males have a dark bluish green lower back and rump; Azure-crowned shows metallic bronze nape and back, with greenish bronze rump and uppertail coverts.
4. Tail pattern (females/immatures): Female Crowned Woodnymphs have blue-black tails with white tips on the outer three pairs of feathers; Azure-crowned immatures have bronze-green tails with whitish tips, but adults lack strong white tips.
5. Bill color (all ages): Azure-crowned Hummingbird has a two-toned bill: black maxilla and dull pink mandible with a black tip. Crowned Woodnymph's bill color is not described as bicolored and is typically dark.
6. Face color (adults): Azure-crowned has a mostly bluish green face, while Crowned Woodnymph's face is not distinctly colored.
7. Sexual dimorphism: Both species show limited sexual dimorphism, but in Crowned Woodnymph, females are much paler below than males, while in Azure-crowned, sexes are very similar except for crown brightness.
8. Immature marks: Azure-crowned immatures have grayish buff tips to uppertail coverts and a buff wash to the underparts; Crowned Woodnymph immatures are dull green above and pale gray below (females) or dusky with limited iridescence (males).
9. Size and bulk: Azure-crowned is slightly heavier and may look bulkier, but this is subtle and not reliable in the field.
10. Tail shape: Crowned Woodnymph males have a deeply forked tail; Azure-crowned's tail is less deeply forked and more bronze-green overall.
11. Subspecies variation: Be aware that some Crowned Woodnymph subspecies (e.g., T. c. fannyae) have green crowns, which can overlap with Azure-crowned, but underpart color and tail pattern still separate them.
12. Perched vs. in flight: Underpart color and crown are best seen on perched birds; tail pattern may be visible in flight, especially in females and immatures.
13. Habitat context: If seen in pine savanna, Azure-crowned is more likely, but both can occur in forested areas.
14. Pitfalls: Immature and female Crowned Woodnymphs can be confused with Azure-crowned due to pale underparts, but Woodnymphs are always grayish below, never pure white, and lack bronze-green sides.
15. Do not rely on voice: No diagnostic vocal differences are described in the sources.

Size

Both species are similar in length (Crowned Woodnymph: 8.5–11.5 cm; Azure-crowned: 10–11.5 cm), but Azure-crowned Hummingbird is consistently heavier (males ~5.8 g, females ~5.4 g) compared to Crowned Woodnymph (males 4–5.5 g, females 3.5–4.2 g). This difference is subtle and rarely diagnostic in the field, but Azure-crowned may appear slightly bulkier, especially in the hand.

Plumage

• Immatures: Both species' immatures are duller than adults, but Azure-crowned immatures have grayish buff tips to the uppertail coverts, whitish tips on outer tail feathers, and a buff wash to the underparts. Immature Crowned Woodnymph males are dusky overall with limited iridescent purple, while immature females are dull green above and entirely pale gray below.

• Adult males: Crowned Woodnymph males (nominate) have a violet crown, upper back, and belly, with a glittering green throat and chest, and a deeply forked blue-black tail. Azure-crowned males have a bright metallic blue (or green in S. c. chlorostephana) crown, metallic bronze nape and back, and white underparts with bronze-green sides.

• Adult females: Female Crowned Woodnymphs are bright green above, pale gray throat and chest, and darker gray belly, with blue-black tails tipped white. Azure-crowned females have a duller blue to greenish blue crown, bronze-green upperparts, white underparts with bronze-green sides, and a similar tail pattern to males.

• Tail: Crowned Woodnymph females have white tips on the outer three pairs of tail feathers; Azure-crowned immatures have whitish tips on the outer tail feathers, but adults' tails are bronze-green without strong white tips.

Behaviour

Both species forage for nectar in similar ways, using both trap-lining and territorial defense. There is no strong behavioral distinction in the field, though Azure-crowned Hummingbird is noted to forage from understory to canopy and may be seen hovering at pine needles and bark crevices in savanna habitat.

Habitat

Ranges overlap in Central America (Belize, Guatemala, Honduras, Nicaragua), but Crowned Woodnymph extends further south to northern Peru, while Azure-crowned is more northerly, reaching Mexico. Both use forested habitats, but Azure-crowned is also found in pine savannas. Habitat alone is not diagnostic where ranges overlap.