Albatrosses

Albatrosses produce a single, helpless chick, which in most species requires a full year to leave the nest, longer than any other seabird. This is almost certainly because of the great effort required to collect food for the chick, who may be left alone for periods of 30-40 days while the parents forage at sea, and even up to 80 days in the case of the wandering albatross.

To compensate for their lengthy absences, adults feed their chicks a rich meal of oil, procured from their fishy diet. As a result, albatrosses have been called the "oil tankers" of the bird world: a stream of oil, produced in the adult stomach, is delivered into the hungry chick's bill. In this way the young birds are able to develop a layer of fat to sustain them during long parental foraging trips.