Cochran Frog vs Polynesian rat

Nymphargus cochranae compared with Rattus exulans

Key Differences

• Cochran Frog is Vulnerable while Polynesian rat is Least Concern.

Taxonomic Classification

Rank	Cochran Frog	Polynesian rat
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Amphibia (Amphibians)	Mammalia (Mammals)
Order	Anura (Frogs & Toads)	Rodentia (Rodents)
Family	Centrolenidae	Muridae (Mice & Rats)
Genus	Nymphargus	Rattus
Species	Nymphargus cochranae	Rattus exulans

Evolutionary Relationship

Cochran Frog and Polynesian rat share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Cochran Frog

VU — Vulnerable

Polynesian rat

LC — Least Concern

Physical Characteristics

Attribute	Cochran Frog	Polynesian rat
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cochran Frog

Habitat

Typically found in freshwater habitats, moist forests, and wetlands.

Range

Found in Colombia. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Polynesian rat

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical coniferous forests, among 4 distinct biome types spanning the Australasia and Indomalayan realms. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Asia (6 countries), Europe (United Kingdom), North America (United States), Oceania and the Pacific (11 countries), and South America (Chile).

Cochran Frog

The Cochran frog (Nymphargus cochranae) is a small glass frog in the family Centrolenidae, native to the cloud forests of the western and central Andes in Colombia. Like other centrolenid frogs, it is characterised by semi-transparent or translucent ventral skin through which internal organs — including the heart, liver, and digestive tract — are visible, a feature that gives the family its common name. The species inhabits humid montane rainforest along streams at elevations typically between 1,500 and 2,800 metres, where males call from vegetation overhanging fast-flowing streams to attract females. Eggs are deposited in gelatinous masses on leaves or rocks above the water; upon hatching, tadpoles drop into the stream below and develop in the current-swept environment. Nymphargus cochranae is classified as Vulnerable by the IUCN, primarily due to ongoing deforestation and degradation of cloud forest habitats driven by agricultural expansion, cattle ranching, and coca cultivation across its Colombian Andean range. Glass frogs are additionally sensitive to stream water quality, making them useful bioindicators of watershed health. The species was named in honour of the eminent American herpetologist Doris Mable Cochran of the Smithsonian Institution, who made foundational contributions to Central and South American amphibian taxonomy in the mid-twentieth century. Continued habitat protection and reforestation efforts are critical for its long-term survival.