Age at first breeding of the African Penguin

Re-sightings of African Penguins Spheniscus demersus flipper-banded as chicks were used to estimate the age of first breeding. Data from five breeding colonies in three regions were analysed: Ichaboe and Mercury islands, Namibia; Dassen and Robben islands, Western Cape and Bird Island, Algoa Bay, Eastern Cape, South Africa. Between 6% and 9% of chicks banded at each colony were subsequently recorded breeding. The average age at first breeding was 4-6 years (range 2-8 years). Oiling, and the subsequent cleaning and rehabilitation procedures, did not affect the age of first breeding. Mean age at first recorded breeding differed between cohorts at the same colony by up to 2.4 years and between colonies by up to 1.1 years. It averaged later at Mercury Island (6 years) than at the other four colonies (5 years). Penguins from colonies in the Western Cape of South Africa, where penguin numbers are generally increasing, bred at a significantly younger age than at colonies in the Eastern Cape and Namibia. However, re-sighting effort was not uniform among colonies or between years and probably affected differences between cohorts and colonies.