Common Loon vs Common Roller

Gavia immer compared with Ancylis badiana

Key Differences

• Common Loon is Not Evaluated while Common Roller is Least Concern.

Taxonomic Classification

Rank	Common Loon	Common Roller
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Chordata (Chordates)	Arthropoda (Arthropods)
Class	Aves (Birds)	Insecta (Insects)
Order	Gaviiformes (Gaviiformes)	Lepidoptera (Butterflies & Moths)
Family	Gaviidae	Tortricidae
Genus	Gavia	Ancylis
Species	Gavia immer	Ancylis badiana

Evolutionary Relationship

Common Loon and Common Roller share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Common Loon

NE — Not Evaluated

Common Roller

LC — Least Concern

Physical Characteristics

Attribute	Common Loon	Common Roller
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Loon

Habitat

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

Range

Distributed across Belgium, Denmark, Norway, Sweden, and United States.

Common Roller

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Common Loon

<em>Gavia immer</em>, the common loon or great northern diver, is a large aquatic bird in the family Gaviidae, known for its haunting, yodeling calls across northern lakes. It is found in Belgium, Denmark, Norway, Sweden, and the United States, breeding on freshwater lakes in boreal and subarctic regions and wintering along marine coastlines. The common loon is adept in aerial, terrestrial, and aquatic environments, though it is most highly specialized for diving, using its strong feet positioned far back on its body to pursue fish underwater. It typically feeds on fish, supplemented by crustaceans and aquatic invertebrates. Its striking summer plumage features a black-and-white checkered back and a deep black head with a characteristic white necklace pattern. The species has not been evaluated for IUCN conservation status. Common loons require clear, fish-rich lakes for successful breeding and are sensitive to water quality degradation and human disturbance at nesting sites. Their distinctive calls are emblematic of wilderness in North America and Scandinavia.

Common Roller

<em>Ancylis badiana</em>, the common roller, is a small moth in the family Tortricidae, order Lepidoptera. It is distributed across northwestern Europe, with documented records from Belgium, Denmark, Norway, and Sweden, typically inhabiting woodland margins, hedgerows, scrubland, and areas where its larval host plants are abundant. The species is assessed as Least Concern on the IUCN Red List. Tortricid moths in the genus Ancylis are commonly known as "rollers" or "leafrollers" because their larvae typically roll or fold leaves of host plants to create sheltered feeding structures. <em>Ancylis badiana</em> larvae feed on the foliage of various herbaceous plants, particularly species in the pea family (Fabaceae). Adults are small moths with intricately patterned wings that provide camouflage against bark and plant material. Adult moths are primarily nocturnal and are attracted to light, while larvae are cryptic within their leaf shelters. Biological traits such as lifespan, body measurements, and detailed diet host range remain poorly documented beyond general family-level characteristics. The species typically completes one to two generations per year in temperate European climates, overwintering as pupae. It is considered a minor component of invertebrate biodiversity in European lowland habitats.

Shared Countries

Both species can be found in 4 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden