Choco Yellow-shouldered Bat vs Common Fat-tailed Mouse Opossum

Sturnira koopmanhilli compared with Thylamys pusillus

Key Differences

• Choco Yellow-shouldered Bat is Data Deficient while Common Fat-tailed Mouse Opossum is Least Concern.

Taxonomic Classification

Rank	Choco Yellow-shouldered Bat	Common Fat-tailed Mouse Opossum
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class same	Mammalia (Mammals)	Mammalia (Mammals)
Order	Chiroptera (Bats)	Didelphimorphia (Didelphimorphia)
Family	Phyllostomidae	Didelphidae
Genus	Sturnira	Thylamys
Species	Sturnira koopmanhilli	Thylamys pusillus

Evolutionary Relationship

Choco Yellow-shouldered Bat and Common Fat-tailed Mouse Opossum share a common ancestor at the Class level: Mammalia. (Mammals)

Conservation Status

Choco Yellow-shouldered Bat

DD — Data Deficient

Common Fat-tailed Mouse Opossum

LC — Least Concern

Physical Characteristics

Attribute	Choco Yellow-shouldered Bat	Common Fat-tailed Mouse Opossum
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Choco Yellow-shouldered Bat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Distributed across Colombia and Ecuador.

Common Fat-tailed Mouse Opossum

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Choco Yellow-shouldered Bat

The Choco Yellow-shouldered Bat (Sturnira koopmanhilli) is a medium-sized frugivorous bat in the family Phyllostomidae, endemic to the Chocó biogeographic region of northwestern South America, where it occurs in the humid forests of the Pacific slope of Colombia and adjacent Ecuador. It belongs to the genus Sturnira — the yellow-shouldered bats — characterised by males bearing distinctive yellowish, orange, or reddish shoulder glands (from which the group's name derives), robust bodies, and rounded ears. Like all Sturnira, this species is primarily frugivorous, consuming a wide range of small, soft fruits from pioneer and forest trees, and plays an important role as a seed disperser in disturbed forest patches and forest edges. The diet of Solanaceae (nightshade family) fruits is particularly typical of the genus, and Sturnira bats are considered the primary dispersers of many pioneer Solanum species in Neotropical secondary succession, contributing directly to forest regeneration. The IUCN classifies the Choco Yellow-shouldered Bat as Data Deficient, reflecting significant uncertainty about the species' distribution limits, population size, and ecological requirements. The Chocó region continues to experience rapid deforestation, which threatens frugivorous bat diversity even where individual species lack adequate data for formal threat assessment.

Common Fat-tailed Mouse Opossum

The Common Fat-tailed Mouse Opossum (<em>Thylamys pusillus</em>) is a small marsupial belonging to the genus Thylamys within the family Didelphidae. Like other members of its genus, this species typically stores fat in its tail, which becomes swollen during periods of food abundance and is metabolised during leaner times, a physiological adaptation that provides energy reserves. <em>Thylamys pusillus</em> is generally found in diverse terrestrial and aquatic ecosystems, often in dry woodlands, scrublands, and grassland habitats of South America. The species is assessed as Least Concern on the IUCN Red List, indicating it is not currently considered at risk of extinction. Detailed geographic range data are not available in the current record, but members of this genus are typically distributed across parts of Argentina, Bolivia, Paraguay, and Uruguay. Biological traits including average lifespan, body dimensions, and specific dietary composition remain poorly documented in the scientific literature, though Thylamys species are generally considered omnivorous, often consuming insects, small vertebrates, and plant material.