Long-tailed Sylph

Long-tailed Sylph (Aglaiocercus kingii)

Name Origin:
The genus Aglaiocercus combines Greek terms for “splendid” (aglaia) and “tail” (kerkos), referring to the male’s long, iridescent tail streamers. The species name kingii honors Admiral Phillip Parker King, a 19th-century British explorer and naturalist.

Quick Facts

🪶 Length: 16–19 cm (including elongated tail feathers in males)
⚖️ Weight: 4.5–6 g
🌎 Range: Andes from northern Venezuela to central Bolivia
🧭 Elevation: 900–2,500 m
🌸 Diet: Nectar and small insects
🏡 Habitat: Montane forest edge, shrubby clearings, and gardens
🧬 Clade: Lesbiini (a.k.a. “coquettes”)
📊 Status: Least Concern (IUCN 2024)

Subspecies & Distribution

Six recognized subspecies:

1. Aglaiocercus kingii margarethae
   Distribution: Coastal and north-central Venezuela.

2. Aglaiocercus kingii caudatus
   Distribution: Sierra de Perijá and adjacent northern Colombia and western Venezuela.

3. Aglaiocercus kingii emmae
   Distribution: Central Andes of northern Colombia and extreme northwest Ecuador.

4. Aglaiocercus kingii kingii (nominate)
   Distribution: Eastern Andes of Colombia.

5. Aglaiocercus kingii mocoa
   Distribution: Southern Colombia (Nariño), eastern Ecuador, and northern Peru.

6. Aglaiocercus kingii smaragdinus
   Distribution: Eastern Andes of Peru to west-central Bolivia.

Species Overview

The Long-tailed Sylph is a standout Andean hummingbird known for the male’s dramatically long outer tail feathers and shimmering green-blue plumage. It thrives in cool, humid highland environments and is typically found at forest edges, in clearings, and shrubby areas. Males perch openly and often display their tails while feeding or during territorial interactions. Both sexes visit a wide range of native and ornamental flowers and also consume small arthropods.

Male Description:
Iridescent green upperparts with a deep blue-green throat, long blue tail streamers with dark tips, pale postocular line, and slightly decurved black bill.

Female Description:
Shorter tail, green upperparts, whitish or buffy underparts with green spotting on the throat, and a similar pale postocular stripe.

Habitat & Behavior:
Inhabits humid montane forest edges, secondary growth, and gardens, particularly between 1,200 and 2,400 meters. Often seen feeding at flowering shrubs, both native and cultivated. Uses trap-lining foraging or defends flowering territories depending on local flower density. Males perform fluttering display flights, showcasing their long tails from exposed perches.

Conservation Note:
While considered Least Concern, the Long-tailed Sylph depends on intact mid-elevation montane habitats. Fragmentation and agricultural expansion can restrict its range locally, especially in drier or deforested zones. However, it adapts well to gardens and small reserves when suitable floral resources are available.

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Below is the Long-tailed Sylph (Aglaiocercus kingii margarethae)

Photographed at Reserva Ecológica Río Blanco Lodge, Caldas, Colombia

This individual represents the subspecies margarethae, found throughout the Central Andes of Colombia, including the Caldas region. Here, it is common in humid montane forest, forest edge clearings, and gardens at elevation.

Below is the Long-tailed Sylph (Aglaiocercus kingii emmae)

Photographed at Colibrí del Sol ProAves Reserve, Antioquia, Colombia

This individual belongs to the subspecies emmae, restricted to the high-elevation Western Andes of Colombia near the Páramo del Sol region. At Colibrí del Sol, it occurs in humid elfin forest and shrubby páramo transition zones.

Below is the Long-tailed Sylph (Aglaiocercus kingii mocoa)

Photographed in Bosque de Protección Alto Mayo, Fundo Alto Nieva, San Martín, Peru

This individual belongs to the subspecies mocoa, which ranges from southern Colombia into northern Peru. In Alto Mayo, it occupies humid montane forest and cloud forest edge, often visiting flowering shrubs at mid-level perches.