[order] Charadriiformes | [family] Alcidae | [latin] Synthiboramphus antiquus | [UK] Ancient Murrelet | [FR] Guillemot à cou blanc | [DE] Silberalk | [ES] Mérgulo Antiguo | [IT] Urietta antica | [NL] Zilveralk

Zilveralk determination

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A small, stocky bird, the Ancient Murrelet is slate-gray above, with gray and white sides and a white belly. The head is black, and the bill is pale. White on the throat extends back and up to the ears. During the breeding season, the throat is black, with a white band at the neck. The eyebrow is accented with white feathers at this time.

Ancient Murrelets spend most of the time on cold-water seas. They forage over the edge of the continental shelf, and also closer to shore, especially in areas where tidal currents bring food up to the surface. They nest on islands or inland in dense forests with thick moss but little underbrush.

The breeding range of the Ancient Murrelet extends around the entire northern Pacific Rim, stretching from the Sea of Japan to British Columbia. In North America, its breeding range spans Alaska's Aleutian Islands and southern mainland coast, as far south as Vancouver Island. In the Aleutians, the species can be locally common, breeding in over 50 locations. British Columbia, however, is home to at least half of the global population. In winter, the Ancient Murrelet can be found in coastal waters as far south as southern California. The Ancient Murrelet may be far more common in the North American portion of its range.

Small fish, krill, and shrimp make up most of the Ancient Murrelet's diet

This species has a large range, with an estimated global Extent of Occurrence of 100,000-1,000,000 km². It has a large global population estimated to be 1,000,000 individuals (M. Crosby in litt. 2003). Global population trends have not been quantified; there is evidence of a population decline (del Hoyo et al. 1996), but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]

In spring, Ancient Murrelets gather on their colonial breeding grounds. They spend their days at sea, and visit the breeding grounds by night. Early in the breeding season, males arrive after sunset each night and find a suitable perch from which to "sing" to potential mates-highly unusual behavior for a seabird. Once paired, the birds dig a burrow in soft soil, often among tree roots or in some other concealed area. The female lays two elongated, buff colored eggs, which are incubated by both parents for up to 33 days.
Once hatched, Ancient Murrelet chicks are fully feathered and able to move about almost immediately. They spend up to three days in the burrow without being fed. They are then coaxed out by the parents, and make their way to the sea by night. This seaward journey often takes place en masse, as many sets of chicks within the colony may depart for the sea simultaneously. The burrow is often high on a steep, densely forested coastal slope. From here, the tiny chicks undertake a long, dark, descending scramble to the crashing surf below. Once at sea, the chicks are able swimmers, and locate their respective parents via voice recognition. Once reunited, family groups move out to sea, where the parents feed the chicks for at least a month, at which point they are fully grown.

Post-breeding dispersal somewhat limited, some birds remaining within breeding range. Rapid exodus from N British Columbia Jul-Sept, with Marked S movement in Oct in both W and E Pacific, S to California (arrives late Oct) and to Japan and Korea (high numbers present Dec-Mar). Dispersal generally limited to short distances except in Sea of Okhotsk, where birds forced out by winter ice. Returns to breeding areas at least a month before laying begins. Details of winter distribution and movements are lacking throughout range.