Cluster Bat vs Common Fat-tailed Mouse Opossum

Myotis sodalis compared with Thylamys pusillus

Key Differences

• Cluster Bat is Near Threatened while Common Fat-tailed Mouse Opossum is Least Concern.

Taxonomic Classification

Rank	Cluster 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	Vespertilionidae	Didelphidae
Genus	Myotis	Thylamys
Species	Myotis sodalis	Thylamys pusillus

Evolutionary Relationship

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

Conservation Status

Cluster Bat

NT — Near Threatened

Common Fat-tailed Mouse Opossum

LC — Least Concern

Physical Characteristics

Attribute	Cluster Bat	Common Fat-tailed Mouse Opossum
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cluster Bat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in United States. Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

Common Fat-tailed Mouse Opossum

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Cluster Bat

Myotis sodalis, the Indiana bat or cluster bat, is a medium-sized insectivorous bat in the family Vespertilionidae endemic to the eastern United States. It is one of the most endangered bats in North America, listed as Endangered under the U.S. Endangered Species Act and classified as Near Threatened by the IUCN. The species is named for its behavior of clustering in extremely dense hibernation groups—sometimes thousands of bats per square meter—in specific limestone caves and mines during winter. These few critical hibernacula make the species extremely vulnerable to disturbance and disease. Since 2007, Indiana bats have suffered severe mortality from white-nose syndrome, a fungal disease caused by Pseudogymnoascus destructans that disrupts hibernation and causes mass starvation. During summer, Indiana bats roost under loose bark of dead trees and forage for insects over forested landscapes and riparian areas. Foraging individuals consume moths, beetles, and flying insects. Conservation efforts include cave gate protection, white-nose syndrome research, and summer habitat management on public and private lands across the eastern US.

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.