Gray-bellied Night Monkey vs Long-tailed Sylph

Aotus lemurinus compared with Aglaiocercus kingii

Key Differences

• Gray-bellied Night Monkey is Vulnerable while Long-tailed Sylph is Least Concern.

Taxonomic Classification

Rank	Gray-bellied Night Monkey	Long-tailed Sylph
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Mammalia (Mammals)	Aves (Birds)
Order	Primates (Primates)	Apodiformes (Apodiformes)
Family	Aotidae	Trochilidae
Genus	Aotus	Aglaiocercus
Species	Aotus lemurinus	Aglaiocercus kingii

Evolutionary Relationship

Gray-bellied Night Monkey and Long-tailed Sylph share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Gray-bellied Night Monkey

VU — Vulnerable

Long-tailed Sylph

LC — Least Concern

Physical Characteristics

Attribute	Gray-bellied Night Monkey	Long-tailed Sylph
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Gray-bellied Night Monkey

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Distributed across Colombia, Ecuador, and Venezuela. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Long-tailed Sylph

Habitat

Typically found in various aerial, terrestrial, and aquatic environments.

Range

Distributed across Colombia, Ecuador, Norway, and Venezuela.

Long-tailed Sylph

One of the most strikingly ornamented hummingbirds, male long-tailed sylphs have iridescent green plumage and dramatically elongated, ribbon-like outer tail feathers reaching up to 22 cm — over three times the body length. Found in Andean cloud forests of Colombia and Venezuela, they inhabit humid montane forest between 1,400–2,800 meters elevation. Males perform elaborate display flights to attract females. Their extravagant tails are a classic example of sexual selection via female preference.

Shared Countries

Both species can be found in 3 countries:

🇨🇴 Colombia 🇪🇨 Ecuador 🇻🇪 Venezuela