IUCN threat status:

Endangered (EN)

Brief Summary

Read full entry

Biology

The preferred habitat of the bank cormorant, over kelp beds, provides a wealth of prey, such as fish, crustaceans (particularly Cape rock lobster) and cephalopods, to feed on. They primarily feed from the sea bottom amongst the kelp, but also feed over shingle or coarse sand, and take large numbers of pelagic goby (Sufflogobius bibarbatus) from mid-water (2) (6). Like penguins, cormorants are pursuit divers, whereby they dive into the water and pursue their prey by propelling themselves with their large, webbed feet. Unlike penguins, their feathers are not waterproof, and the extra weight of wet plumage helps them dive even deeper. After diving they clamber out onto the rocks, holding their wings out to dry (3). Males perform a display in order to attract a female, in which they throw their head backwards until it touches their back, with the bill pointing vertically upwards, and then sweep their head forward and down. This backward and forward movement alternately covers and exposes the white patch on their rump (7). Bank cormorants generally breed all year round, and are thought to occasionally raise two broods in one year (2) (7). The nests are constructed from seaweed, which sticks well to the smooth sloping rock on which its nests, and also sticks and feathers, stuck together with excreta, or guano (7). They are built in colonies of up to 100 pairs, and clutches of one to three eggs are laid, but with their proximity to the ocean, nests are frequently lost to rough seas (4). Both parents incubate the eggs for 29 – 30 days before naked chicks hatch, which soon develop black down (2) (7). Whilst adults are fairly sedentary, juveniles are known to disperse over hundreds of kilometres, and begin breeding themselves after two or three years (4).

Trusted

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!