Phoebetria
| Sooty albatross | |
|---|---|
 |
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| Light-mantled albatross | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Procellariiformes |
| Family: | Diomedeidae |
| Genus: |
Phoebetria L. Reichenbach, 1853 |
| Species | |
|
Phoebetria fusca |
|
Phoebetria fusca
Sooty albatross
Phoebetria palpebrata
Light-mantled albatross
The sooty albatrosses are small albatrosses from the genus Phoebetria. There are two species, the sooty albatross, Phoebetria fusca, and the light-mantled albatross, Phoebetria palpebrata. The sooties have long been considered distinct from the rest of the other albatrosses, and have retained their generic status through the many revisions of the family over the last 150 years. They have traditionally been thought of as primitive, sharing some morphological features with the other petrel families. However, molecular work examining the has shown that the taxon is related to the mollymawks, and that the two taxa are distinct from the great albatrosses and the North Pacific albatrosses.
Both have distinctive blackish plumage over the head, wings and bellies. The sooty albatross has a dark back and mantle as well, whereas the light-mantled has an ashy-grey mantle, back and rump. The two species can also be told apart by the narrow yellow line on the sooty's bill. Despite the differences between the two species they can be hard to tell apart at sea, especially in poor light. Both species have a white incomplete eye-ring, dark bills and grey feet. They are among the smallest albatrosses, with wingspans of 200 cm (79 in) and are very narrow as well. The light-mantled, at 2.5 to 3.7 kg (5.5–8.2 lb) and sometimes to 4.6 kg (10 lb), is larger than the sooty, at 2.4 to 2.7 kg (5.3–6.0 lb). Unique amongst the albatrosses they have long stiff wedge shaped tails, the purpose of which is unclear but seems to be related to their ability to dive for food.
The two species, like most seabirds, are colonial, although they are less colonial than the other species of albatrosses. In fact, on some breeding islands (like Tristan da Cunha) they may nest in very small groups or clusters of two to five nests, and the light-mantled will even nest singly. This is in part due to the influence of humans, and in part due to their tendency to nest on cliffs, unlike the flatter ground preferred by other albatrosses. Both species build cone shaped nests and lay a single egg. Eggs are incubated for 70 days, by both parents, the male taking the first stint after laying (lasting 11 days) thereafter both parents taking it in turns of 7 days. After hatching the chick is brooded for 20 days until it is able to thermoregulate on its own, after which both parents undertake the task of feeding it, on average bringing food to the chick every three days. The chick is fed for about 160 days, until it is able to fledge. There is no parental care after fledging. They are able to complete a breeding cycle in under a year, but do not breed in consecutive years, instead taking a year off and returning to breed every two years. Around 22% of the sooty albatrosses survive until adulthood (there are no figures for light-mantled). Both species return to the breeding colony after 7–10 years of fledging, and begin to breed a few years later.
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Wikipedia