In the nonbreeding season, it may be found as far north as the mouth of the Congo, also extending its home up the east coast of South Africa as far as Mozambique.

[1] The Cape cormorant is an almost entirely glossy black bird, though in breeding condition it has a purplish tinge and a few white plumes on the head, neck, and cloacal areas.

Its gular skin is a deep orangey yellow; unusually for a cormorant, its lores are feathered.

The bird's wing is about 240–280 mm in extent, and it weighs 800–1600 grams, with little sexual dimorphism.

Cape shags commonly forage in flocks, taking schooling fish, such as pilchards, anchovies, and sand eels from mid-water.