Coastal Flat-body vs Common Merganser

Agonopterix yeatiana compared with Mergus merganser

Key Differences

• Coastal Flat-body is Near Threatened while Common Merganser is Least Concern.

Taxonomic Classification

Rank	Coastal Flat-body	Common Merganser
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Arthropoda (Arthropods)	Chordata (Chordates)
Class	Insecta (Insects)	Aves (Birds)
Order	Lepidoptera (Butterflies & Moths)	Anseriformes (Anseriformes)
Family	Depressariidae	Anatidae
Genus	Agonopterix	Mergus
Species	Agonopterix yeatiana	Mergus merganser

Evolutionary Relationship

Coastal Flat-body and Common Merganser share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Coastal Flat-body

NT — Near Threatened

Common Merganser

LC — Least Concern

Physical Characteristics

Attribute	Coastal Flat-body	Common Merganser
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Coastal Flat-body

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, and Sweden. Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

Common Merganser

Habitat

Typically found in various aerial, terrestrial, and aquatic environments.

Range

Found across Europe (5 countries) and North America (United States).

Coastal Flat-body

Agonopterix yeatiana, the coastal flat-body, is a small moth in the family Depressariidae native to coastal and calcareous grassland habitats across western and northern Europe, with records from Belgium, Denmark, and Sweden. Moths in the family Depressariidae, commonly called flat-body moths due to the depressed posture they adopt when resting with wings held flat against the surface, are associated predominantly with umbellifer plants of the family Apiaceae as larval hosts. Agonopterix yeatiana larvae feed on wild carrot (Daucus carota), wild parsnip (Pastinaca sativa), and related coastal and grassland Apiaceae species, inhabiting the open, often calcareous or sandy habitats where these plants grow. Adult moths have greyish-brown forewing with a distinctive pattern of spots and dashes and reach approximately 8–12 millimeters in wingspan. The species is classified as Near Threatened by the IUCN, reflecting declines associated with the loss of traditional hay meadow management, coastal grassland degradation, and scrub encroachment that eliminates the open, flower-rich grassland habitats supporting its host plants. Agricultural intensification has reduced wild umbellifer populations significantly across lowland Europe, reducing food resources for larvae of specialist moths like A. yeatiana.

Common Merganser

<em>Mergus merganser</em>, the common merganser or goosander, is a large diving duck in the family Anatidae, broadly distributed across Europe and North America. It is classified as Least Concern on the IUCN Red List. This species is capable of aerial, terrestrial, and aquatic locomotion, but is most specialized for underwater pursuit of prey. The common merganser is typically piscivorous, diving in clear, fast-flowing rivers and lakes to catch fish using its serrated bill, which provides a firm grip on slippery prey. Males display striking breeding plumage with a dark green head, white body, and red bill, while females are grey with a rusty-brown head and crested nape. The species nests in tree cavities, cliff ledges, and artificial nest boxes near freshwater habitats. It requires clean, well-oxygenated rivers and lakes for foraging, making it sensitive to water quality degradation and overfishing of prey species. Common mergansers are migratory in northern parts of their range, moving to coastal and ice-free inland waters during winter months.

Shared Countries

Both species can be found in 3 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇸🇪 Sweden