Shags - Western Isles Bird Sightings
Shags look very similar to cormorants, however, shags have a washed out dull yellowish bill. Cormorants have heavier bills. Cormorants have a yellowish patch at the base of the bill which is greyish.
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Shags - Isle of Lewis and Harris Bird Sightings
Shags produce distinctive shaggy crests on their heads during breeding season, while cormorants do not. Shags generally are smaller than cormorants, with narrower beaks and leaner bodies. Shags have a peaked crown compared to flat one of Cormorant