Chuuk Flying Fox vs Coastal Silver-stiletto

Pteropus pelagicus compared with Acrosathe annulata

Key Differences

• Chuuk Flying Fox is Endangered while Coastal Silver-stiletto is Least Concern.

Taxonomic Classification

Rank	Chuuk Flying Fox	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	Pteropodidae (Fruit Bats)	Therevidae
Genus	Pteropus (Flying Foxes)	Acrosathe
Species	Pteropus pelagicus	Acrosathe annulata

Evolutionary Relationship

Chuuk Flying Fox and Coastal Silver-stiletto share a common ancestor at the Kingdom level: Animalia. (動物)

Conservation Status

Chuuk Flying Fox

EN — Endangered

Coastal Silver-stiletto

LC — Least Concern

Physical Characteristics

Attribute	Chuuk Flying Fox	Coastal Silver-stiletto
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Chuuk Flying Fox

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.

Chuuk Flying Fox

The Chuuk flying fox (Pteropus pelagicus) is a large fruit bat in the family Pteropodidae, endemic to Chuuk (Truk) Lagoon in the Federated States of Micronesia, central Pacific Ocean. It occupies forested islands within the lagoon, roosting in large trees and foraging nocturnally on ripe fruits, nectar, and flowers of native tropical vegetation. As one of the few native pollinators and seed dispersers on these small island ecosystems, the Chuuk flying fox plays an essential ecological role in maintaining forest regeneration. The species is classified as Endangered by the IUCN, primarily due to its extremely restricted range—confined to a small island group—and ongoing hunting pressure for bushmeat, which is traditional in parts of Micronesia. Habitat loss from typhoons, agricultural conversion, and human development further threatens its already limited habitat. Pteropus bats across the Pacific have faced severe declines from overhunting, with several island species now extinct. The Chuuk flying fox has a wingspan that can exceed one meter, and roosts colonially in forest canopy trees. International agreements and national legislation within the Federated States of Micronesia provide some protection, but enforcement remains challenging. Population surveys and community-based conservation programs are urgently needed to stabilize this species.

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.