Brachyramphus
Encyclopedia
Brachyramphus is a small genus of seabird
s from the North Pacific. It consists of three species:
These are unusual members of the auk
family, often nesting far inland in forest
s 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 fossil
s, found in the San Diego Formation
of the southwestern USA: Brachyramphus dunkeli and Brachyramphus pliocenum
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.
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 fledge
s and flies unaccompanied to the sea. Breeding success is low and chick mortality high.
, due to the loss of old growth forest
to logging
and retreating, entanglement in fishing
gear and oil spill
s.
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
s from the North Pacific. It consists of three species:
- Marbled MurreletMarbled MurreletThe Marbled Murrelet is a small seabird from the North Pacific. It is a member of the auk family. It nests in old-growth forests or on the ground at higher latitudes where trees cannot grow...
, Brachyramphus marmoratus - Long-billed MurreletLong-billed MurreletThe Long-billed Murrelet is a small seabird from the North Pacific. It is an unusual member of the auk family, often nesting far inland in old growth forests...
Brachyramphus perdix - Kittlitz's MurreletKittlitz's MurreletThe Kittlitz's Murrelet, is a small alcid found in the waters off Alaska and Eastern Siberia. This critically endangered species is, like the closely related Marbled Murrelet, unusual for seabirds in not being colonial, nesting instead in isolated locations on mountain tops, where the nests were...
, Brachyramphus brevirostris
These are unusual members of the auk
Auk
An auk is a bird of the family Alcidae in the order Charadriiformes. Auks are superficially similar to penguins due to their black-and-white colours, their upright posture and some of their habits...
family, often nesting far inland in forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s 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
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
to the coast of Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
.
2 prehistoric species have been described from Late Pliocene fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s, found in the San Diego Formation
San Diego Formation
The San Diego Formation is a mostly sand, with rock layer from a former bay of San Diego of Late Pliocene age.Besides those of clams and other mollusks, quite a few bird fossils have been found in this geological formation. Among them is a possible ancestor of Cassin's Auklet and the loons Gavia...
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 plumagePlumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
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, krillKrill
Krill is the common name given to the order Euphausiacea of shrimp-like marine crustaceans. Also known as euphausiids, these small invertebrates are found in all oceans of the world...
and other small zooplankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
. 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
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
on bare ground or on a thick lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
- or moss
Moss
Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
-covered branch or hollow. The egg is incubated for a month, then the chick is fed for around 40 days until it fledge
Fledge
Fledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
s 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 habitatHabitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...
, due to the loss of old growth forest
Old growth forest
An old-growth forest is a forest that has attained great age , and thereby exhibits unique ecological features. An old growth forest has also usually reached a climax community...
to logging
Logging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...
and retreating, entanglement in fishing
Fishing
Fishing is the activity of trying to catch wild fish. Fish are normally caught in the wild. Techniques for catching fish include hand gathering, spearing, netting, angling and trapping....
gear and oil spill
Oil spill
An oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially marine areas, due to human activity, and is a form of pollution. The term is mostly used to describe marine oil spills, where oil is released into the ocean or coastal waters...
s.