The Life Cycle of Penguins: Adults: Mating and Breeding
Adult penguins breed every year (except the Kings who can usually only raise at most two chicks every three years). In most species the males return first to the nest sites in the colony and try to attract a female. Females look for strong healthy males who will be able to help with the exhausting process of chick rearing. The degree of pair fidelity between seasons is greatest in the penguins with the shortest breeding seasons (ie the Antarctic penguins: Emperors, Adelies, etc.) and lowest amongst those where there is an extended breeding season (i.e. the warm weather penguins; Humboldts, Africans, etc.). There is a clear advantage in continuing with a previously successful partnership especially when precious time can be saved by avoiding the lengthy rituals of finding a new partner.
Once a pair have formed they will generally perform regular rituals to strengthen the bond between themselves and to ensure that later, when one will go out to sea while the other incubates the nest, they will be able to recognise one another easily. These rituals come in many forms: there are ritual displays and calling, males will often present their female partners with stones or other nesting material, pairs will often preen each other taking care of the feathers that individual birds can find it very hard to reach, etc.
As soon as the bond between is well established they will mate to fertilise the eggs. In each species there is a careful sequence of displays between the male and female to help co-ordinate a successful mating. The sequences of pictures below illustrates the stages in the mating of a pair of African Penguins.
Depending on the species the eggs can be laid from one to three weeks after mating.
Female penguins can be quite devious. In several species (certainly Adelies and Yellow-eyed penguins have been seen behaving in this way) some females select their partners for their reliability in raising chicks, but will mate surreptitiously with other bolder and less caring males on their way to and from the sea. Thus they try to ensure the best chance of survival for their chicks by having a caring "father" to raise them, but at the same time giving them genes from a more aggressive and, by implication, successful male.
We don't know how long penguins live in the wild, there simply haven't been enough long term population studies as yet. The best information available is that penguins tend to live for about 20 years.