Head to head
Rock Shag vs Imperial Shag
Rock Shag
VS Imperial Shag
Both shags dive for fish along cold Southern Hemisphere coastlines, but they come from genuinely separate branches of the cormorant family tree.
| Rock Shag | Imperial Shag | |
|---|---|---|
| Scientific name | Phalacrocorax magellanicus | Leucocarbo atriceps |
| Genus | Phalacrocorax | Leucocarbo |
| Blue eye-ring | Not documented | Present, giving it the name blue-eyed shag |
| Plumage | Mostly dark and glossy, with some white patches | Glossy black-and-white |
| Range | Southern South America and the Falklands | Sub-Antarctic islands and southern South America |
| Conservation status | Least Concern | Least Concern |
| Population trend | Stable | Stable |
| Habitat | Ocean, coastal | Ocean, coastal |
Rock Shag vs Imperial Shag: common questions
Are the rock shag and imperial shag closely related?
No, they belong to entirely different genera despite a similar diving lifestyle, a case of comparable adaptations evolving separately within the wider cormorant family.
Which one has a distinctive blue eye-ring?
The imperial shag has this feature, a vivid ring of blue skin around each eye that gives the species its alternative name, a marking not documented on the rock shag.
Do both overlap in range?
Yes, both species can be found along southern South American coastlines, though the imperial shag also extends into sub-Antarctic islands beyond the rock shag's more limited range.