Coastal Silver-stiletto vs Colombian Weasel

Acrosathe annulata compared with Mustela felipei

Key Differences

• Coastal Silver-stiletto is Least Concern while Colombian Weasel is Vulnerable.

Taxonomic Classification

Rank	Coastal Silver-stiletto	Colombian Weasel
Kingdom same	Animalia (animal)	Animalia (animal)
Phylum	Arthropoda (arthropodes)	Chordata (Chordates)
Class	Insecta (insecte)	Mammalia (mammifères)
Order	Diptera (Diptera)	Carnivora (carnivores)
Family	Therevidae	Mustelidae (Weasels & Otters)
Genus	Acrosathe	Mustela
Species	Acrosathe annulata	Mustela felipei

Evolutionary Relationship

Coastal Silver-stiletto and Colombian Weasel share a common ancestor at the Kingdom level: Animalia. (animal)

Conservation Status

Coastal Silver-stiletto

LC — Least Concern

Colombian Weasel

VU — Vulnerable

Physical Characteristics

Attribute	Coastal Silver-stiletto	Colombian Weasel
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Coastal Silver-stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Colombian Weasel

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

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

Coastal Silver-stiletto

Coastal silver stiletto (Acrosathe annulata) is a slender robber fly in the family Therevidae, native to northwestern Europe, including the United Kingdom, France, the Netherlands, Belgium, and Scandinavia. Adults are found on coastal sand dunes and sandy heathland, where they perch on bare sand to ambush small flying insects. Stiletto flies in the family Therevidae are characterised by a slender body, long pointed abdomen, and predatory habits; adults prey on a variety of small dipterans and other flying insects during warm, sunny periods. Larvae develop in sandy soil, where they are also predatory, feeding on other invertebrate larvae. Acrosathe annulata is a habitat specialist restricted to open, sandy coastal habitats with sparse vegetation—environments that have declined substantially across northwestern Europe due to dune stabilisation, recreational disturbance, and the cessation of traditional dune management. The IUCN lists it as Least Concern, though regional conservation bodies in the United Kingdom have flagged population declines. It is considered an indicator of high-quality coastal sand dune habitats and is monitored through national invertebrate surveys.

Colombian Weasel

<em>Mustela felipei</em>, the Colombian weasel, is one of the rarest and least-known mustelids in the world, endemic to the Andes of Colombia. This species is assessed as Vulnerable by the IUCN, reflecting genuine conservation concern arising from its extremely restricted range and the continued degradation of Andean cloud forest and montane stream habitats upon which it depends. <em>Mustela felipei</em> is associated with rocky stream margins and humid upland forests, where it is believed to hunt fish, invertebrates, and small vertebrates in a manner consistent with other semi-aquatic weasels. The species was described scientifically only in 1978, and very few individuals have been observed in the wild, meaning that fundamental aspects of its ecology, behaviour, and reproductive biology remain unknown. Its small body size and cryptic habits make field observation exceptionally challenging. The primary threats to this species include deforestation, water pollution, and stream alteration within its narrow elevational range in the Colombian Andes. Biological traits of this species remain poorly documented in the scientific literature.