Big Free-tailed Bat vs Coastal Silver-stiletto

Nyctinomops macrotis compared with Acrosathe annulata

Taxonomic Classification

Rank	Big Free-tailed Bat	Coastal Silver-stiletto
Kingdom same	Animalia (动物界)	Animalia (动物界)
Phylum	Chordata (脊索动物门)	Arthropoda (节肢动物门)
Class	Mammalia (哺乳動物)	Insecta (昆蟲綱)
Order	Chiroptera (翼手目)	Diptera (雙翅目)
Family	Molossidae	Therevidae
Genus	Nyctinomops	Acrosathe
Species	Nyctinomops macrotis	Acrosathe annulata

Evolutionary Relationship

Big Free-tailed Bat and Coastal Silver-stiletto share a common ancestor at the Kingdom level: Animalia. (动物界)

Conservation Status

Big Free-tailed Bat

LC — Least Concern

Coastal Silver-stiletto

LC — Least Concern

Physical Characteristics

Attribute	Big Free-tailed Bat	Coastal Silver-stiletto
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Big Free-tailed Bat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Distributed across Colombia, Ecuador, and Venezuela.

Coastal Silver-stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Big Free-tailed Bat

The Big Free-tailed Bat (Nyctinomops macrotis) is a species in the genus Nyctinomops. It is currently classified as Least Concern 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.