diagnostics
75-76 cm; 1.8-2.1 kg. Sexes alike in plumage colouration. A heavily built, large cormorant, with a distinctive, peaked forecrown. Adult breeding plumage is entirely black, apart from white rump patch. Feathers of head and body glossed greenish, while the scapulars, wing coverts and feathers of the upper mantle have a bronze iridescence. Bill dark grey-black; eye-ring, bare gular pouch, legs and feet black. Juveniles entirely black, without iridescence. Eyes are unique in having bi-coloured halves: pale brown on the top half and blue on the lower half (Crawford and Cooper 2005).
trophic
Bank Cormorants are found on the coast and at sea mainly in inshore waters (less than 10 km), breeding mainly on islands and islets and on rocky outcrops of the mainland, where they build elevated nests. Using data for related species, Crawford and Shelton (1981) assumed an age at breeding of four years for Bank Cormorants and an annual survival rate of 0.8 for adults. A survival rate of 0.8 gives a life expectancy for breeding birds of 3.45 years and hence a generation length of about 7.45 years, although it should be noted that adult survival has never been estimated for this species and 0.8 is inferred from other similar-sized species (Crawford et al. 1999). Similarly, age at first breeding was estimated at three years (Crawford et al. 2001). Bank Cormorants forage benthically over inshore kelp beds, clear rocky or sandy substrate, mainly on West Coast Rock Lobster Jasus lalandii and benthic fish of the Clinidae family (Crawford and Cooper 2005).
