Over winter, the Cape Petrel moves into the more northerly parts of its range, where it generally stays far from shore in the open ocean (2) (4). It returns to the breeding colonies at the beginning of the Austral summer, from mid to late October. Breeding pairs are remarkably monogamous, with between 75 to 85 percent of adults mating with the same partner as the previous year (3). The nest comprises a shallow scrape or a small collection of stones, usually positioned under an overhanging rock for protection (3) (6). Each year, the female lays just a single egg, which is incubated in shifts by both the parent birds. Similarly, both the male and female share feeding and caring responsibilities once the chick has hatched. At the nest, the adults and the nestlings deter predators such as skuas (Catharacta spp.) by spitting stomach oil with incredible accuracy (3).
The Cape petrel is an opportunistic forager, with krill, fish, squid and carrion forming the bulk of its diet. Although it usually forages by seizing and scavenging from the surface, occasionally it will dive up to one metre below the surface in pursuit of prey (3). In addition, this petrel is known to commonly follow ships in order to pick up discarded scraps and offal (3) (5).