Saturday, April 28, 2012

>>Genus Brachyramphus

Brachyramphus

Brachyramphus
Long-billed Murrelet
Brachyramphus perdix
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Aves
Order:Charadriiformes
Family:Alcidae
Genus:Brachyramphus
Brandt, 1837
species
B. marmoratus
B. perdix
B. brevirostris
Brachyramphus is a small genus of seabirds from the North Pacific. It consists of three species:
  • Marbled Murrelet, Brachyramphus marmoratus
  • Long-billed Murrelet Brachyramphus perdix
  • Kittlitz's Murrelet, Brachyramphus brevirostris
These are unusual members of the auk family, often nesting far inland in forests or on mountain tops. The Long-billed Murrelet was considered conspecific with the Marbled Murrelet until 1998, when Friesen et al. showed that the mtDNA variation was greater between these two forms than between Marbled and Kittlitz's Murrelets.
These species breed in the subarctic North Pacific. They tend to remain coastal in winter, either staying near the breeding grounds, or, in the case of Long-billed, migrating to the coast of Japan.
2 prehistoric species have been described from Late Pliocene fossils, found in the San Diego Formation of the southwestern USA: Brachyramphus dunkeli and Brachyramphus pliocenum

Description

These are small chunky auks, no more than 25 cm long. Like other auks, they have plumage that varies by season. The non-breeding appearance is typically white underneath with mainly black upperparts. The breeding plumage is distinctive in this group; most auks are strongly contrasted with black and white when breeding, but Brachyramphus species are mainly brown, with pale feather edges giving a scaly appearance; the central underparts, normally below the surface on a swimming bird, are white.

Behaviour and breeding

These murrelets feeds at sea on small fish, larval fish, krill and other small zooplankton. Chicks are fed with larger fish carried in the bill.
The breeding behaviour of this genus is very unusual. Unlike most other seabirds, they do not breed in colonies or even necessarily close to the sea, instead nesting, depending on species, on branches of old-growth conifers, mountaintops, or on open ground. They lay one egg on bare ground or on a thick lichen- or moss-covered branch or hollow. The egg is incubated for a month, then the chick is fed for around 40 days until it fledges and flies unaccompanied to the sea. Breeding success is low and chick mortality high.

Threats

All three Brachyramphus murrelets are globally threatened and declining in numbers. The biggest threat are the loss of nesting habitat, due to the loss of old growth forest to logging and retreating, entanglement in fishing gear and oil spills.


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