Breeding usually starts when they are 3 years old and takes place mainly in the Balearic Islands, in colonies. The nests are made of scattered plant material and located in rock crevices or set back on ledges in caves. Females lay just one egg which requires incubating for around 50 days. After laying, the female will go in search of food which could take her away from the nest for up to two days, so initially, the male will usually undertake the first incubation.