Birdlike Noctule vs Coastal Silver-stiletto

Nyctalus aviator compared with Acrosathe annulata

Key Differences

• Birdlike Noctule is Near Threatened while Coastal Silver-stiletto is Least Concern.

Taxonomic Classification

Rank	Birdlike Noctule	Coastal Silver-stiletto
Kingdom same	Animalia (動物)	Animalia (動物)
Phylum	Chordata (脊索動物)	Arthropoda (節足動物)
Class	Mammalia (哺乳類)	Insecta (昆虫)
Order	Chiroptera (翼手目)	Diptera (ハエ目)
Family	Vespertilionidae	Therevidae
Genus	Nyctalus	Acrosathe
Species	Nyctalus aviator	Acrosathe annulata

Evolutionary Relationship

Birdlike Noctule and Coastal Silver-stiletto share a common ancestor at the Kingdom level: Animalia. (動物)

Conservation Status

Birdlike Noctule

NT — Near Threatened

Coastal Silver-stiletto

LC — Least Concern

Physical Characteristics

Attribute	Birdlike Noctule	Coastal Silver-stiletto
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Birdlike Noctule

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Coastal Silver-stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Birdlike Noctule

The Birdlike Noctule (Nyctalus aviator) is a species in the genus Nyctalus. It is currently classified as Near Threatened on the IUCN Red List. Typically found in diverse terrestrial and aquatic ecosystems.

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.