There are 2-3 eggs usually laid in March or April. Incubation lasts 28-30 days. Both parents care for the naked, helpless chicks. They feed their chicks by regurgitation. Fledging requires 63-76 days, with little or no post fledging care depending on the length of time the young spent in the nest.
Sexual maturity is reached after two to five years.
The major cause of their decline was pesticide poisoning. Since DDT was banned, there has been a full recovery on the east coast and other populations are showing steady improvement. Threats today include becoming snarled in abandoned fishing lines and flying into overhead wires. NZP birds are rehabilitated birds, injured in this fashion. Other factors include human disturbance of nesting colonies and reduction of fish stocks by excessive commercial fishing.