common hydra vs Gray/Purple Heron

Hydra vulgaris compared with Ardea cinerea

Key Differences

• common hydra is Not Evaluated while Gray/Purple Heron is Least Concern.

Taxonomic Classification

Rank	common hydra	Gray/Purple Heron
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Cnidaria (Cnidarians)	Chordata (Chordates)
Class	Hydrozoa (Hydrozoa)	Aves (Birds)
Order	Anthoathecata (Anthoathecata)	Pelecaniformes (Pelecaniformes)
Family	Hydridae	Ardeidae
Genus	Hydra	Ardea
Species	Hydra vulgaris	Ardea cinerea

Evolutionary Relationship

common hydra and Gray/Purple Heron share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

common hydra

NE — Not Evaluated

Gray/Purple Heron

LC — Least Concern

Trend: Stable →

Physical Characteristics

Attribute	common hydra	Gray/Purple Heron
Diet	—	Carnivore
Average Lifespan	—	15 years
Average Length	—	95 cm
Average Weight	—	1.5 kg

Habitat & Geographic Range

common hydra

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, and Sweden.

Gray/Purple Heron

Habitat

Typically found in diverse ecosystems where prey species are available.

Range

Found across Europe (6 countries).

common hydra

<em>Hydra vulgaris</em>, commonly known as the common hydra, is a small freshwater cnidarian in the family Hydridae. Its conservation status has not been formally evaluated by the IUCN. The species is recorded from Denmark, Norway, and Sweden, with its native range understood to encompass Europe broadly. It typically inhabits slow-moving or still freshwater bodies such as ponds, lakes, and streams, where it attaches to aquatic vegetation or submerged substrates. The common hydra is notable for its remarkable regenerative capabilities and has been the subject of substantial biological research. Diet information for this species is not available in current records. Biological traits of this species remain poorly documented in the scientific literature.

Gray/Purple Heron

A large, elegant wading bird reaching up to 1 meter in height, gray herons inhabit wetlands, rivers, lakes, and coastal areas across Europe, Asia, and Africa. Patient, solitary hunters, they stand motionless for long periods before striking fish, frogs, and small mammals with lightning-fast dagger bill strikes. They nest colonially in tall trees in rookeries called heronries, sometimes shared with other colonial waterbirds. Widely distributed and of Least Concern globally.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden