But since they're not closely related, what does account for the similarity of life histories? That is a question I've been mulling over for a long time, and one that has been directly guiding my research for several years.Īlbatrosses hold the age record for seabirds, living sixty to seventy years and continuing to reproduce into their fifties. The two groups are members of two well-differentiated evolutionary orders, three major steps up the hierarchy from the species level.
How did these birds come to have such similar, unusual, life histories? It would be natural to think that the albatrosses (there are between fourteen and twenty species, depending on which ornithologist you agree with) and the frigatebirds (five species) are closely related in evolutionary terms. Frigatebirds live for decades, but albatrosses hold the record for seabirds, reaching ages of sixty to seventy years and continuing to reproduce into their fifties. And beyond their oceanic habitat and their superb flying skills, the two birds share some distinctive features of life history: they have the lowest rates of reproduction and the latest onset of maturity among all birds. Each bird is a magnificent flier in its own environment: an albatross can spend between 90 and 95 percent of its life soaring on cold gales over subantarctic seas a frigatebird can ride warm thermal updrafts over tropical oceans for more than a week at a time without touching down on land or water.
#FRIGATE BIRDS FREE#
Their overall shapes, albeit distinct, free them from any dependence on terra firma except when breeding. Both rely entirely on the ocean for food. Mong oceangoing avian species, albatrosses and frigatebirds are the quintessential seabirds. Although frigatebirds can fish for themselves, they are also notorious for harassing other seabirds and robbing them of prey in midair. Now showing ornithologists where the birds go.įorked tail and angular wings of a frigatebird confer great maneuverability in flight. Miniature electronic trackers and sensors are Albatrosses and frigatebirds spend most of their long lives soaring
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