Black Guillemot vs Cassin's Auklet
Cepphus grylle compared with Ptychoramphus aleuticus
Side-by-Side Comparison
| Attribute | Black Guillemot | Cassin's Auklet |
|---|---|---|
| Scientific Name | Cepphus grylle | Ptychoramphus aleuticus |
| Order | Charadriiformes | Charadriiformes |
| Family | Alcidae | Alcidae |
| Conservation Status | Least Concern | Near Threatened |
| Length | — | — |
| Wingspan | 30.8 cm (12.1 in) | 24.2 cm (9.5 in) |
| Weight | 421.8666666666666 g (14.88 oz) | 175.0 g (6.17 oz) |
| Diet | -- | -- |
| Clutch Size | 1-2 | 1 |
| Population Trend | — | — |
Habitat Comparison
Conservation Status
Least Concern
Black Guillemot
Near Threatened
Cassin's Auklet
About These Birds
Black Guillemot
Black Guillemot, 30–32 cm, is a compact North Atlantic alcid, distinctive in summer: entirely black with bold white wing patches and vivid red feet. Resident on rocky Arctic and boreal shores year-round; does not undertake long pelagic migrations. Dives to 50 m for blennies and sand eels near shore.
Cassin's Auklet
Cassin's Auklet, 21–23 cm, is a small, almost entirely dark grey auklet breeding in burrows on rocky North Pacific islands from Baja California to the Aleutians. Feeds almost exclusively on zooplankton — euphausiids and copepods — at night. Highly colonial; winters near shore.