Script's Murrelet

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Common Name: Script’s Murrelet
Scientific Name: Synthliboramphus scrippsi

Size: 10 inches (24 cm); 38 cm wingspan

Habitat: North America; western coast of North America. This species is fond of warm, southerly climates. During the breeding season, the entire Script’s murrelet population is concentrated within a fairly small region off the coasts of southern California. However, birds disperse after breeding, sometimes as far north as British Columbia. The majority of the U.S. breeding population of murrelets occurs on the Channel Islands.

During the breeding season, murrelets use the steep slopes and cliffs of islands for nesting. They prefer areas with sufficient vegetation for cover. Away from the breeding season, the birds move far out to sea, preferring the deep waters beyond the continental shelf.

Status: Vulnerable (Listed “Threatened” in California). Global Population: 6,000-15,000 mature individuals and declining. Scripps's Murrelet is mainly threatened by oil spills, as much of its population lives near the busy shipping lanes connecting Los Angeles to other ports. Because a large part of its small population nests in such a small area a single catastrophic oil spill could have far reaching implications. It is also threatened by introduced species such as rats and feral cats; this threat has been lessened lately by efforts to restore its habitat by removing introduced predators. In one case the population of rats was removed from Anacapa Island by the use of poisoned bait, the money for which being paid by a trust fund from an oil spill settlement. Now the murrelet is on track toward federal Endangered Species Act status, thanks to a 2011 Center for Biological Diversity agreement with the U.S. Fish and Wildlife Service compelling action on protecting the bird.

Diet: Small fish and crustaceans. Scripps's Murrelet feeds at sea (but on average not as far from land as Guadalupe Murrelet), often in association with large pelagic predatory fish like tuna, on larval fish like anchovies, sardines and Sebastes rockfish. Like all auks it is a wing-propelled diver, chasing down prey under the water with powerful wingbeats. Interestingly, they are nearly always observed feeding in pairs rather than in flocks. Adults are active at the colony only at night. This curious feeding strategy takes place year-round, including during the breeding season. Since one member of each breeding pair is at the nest throughout the breeding season, unrelated birds may pair up to feed cooperatively.

Breeding: Black above and white on the chin, throat, and belly, this murrelet is very similar in appearance to Craveri’s murrelet, a species that shares a similar range. The two are most easily separated in flight by the distinct white underwing. This species is also very close in resemblance to Script’s Murrelet and was just recently divided into a new species. Facial patterning on the Guadalupe is much whiter above the eye than the Script’s Murrelet.

In early spring, females lay two eggs directly on the ground, usually in a rocky area concealed by dense vegetation. No actual nest is constructed. For about 34 days, both parents take turns incubating the eggs, which vary widely in color, from pure white to blue, green, or even dark brown. Some are heavily spotted, while others are unspotted. The eggs are also extremely large, weighing up to a quarter of the mother’s total body weight—among the largest parent-to-egg size ratio of any bird. The chicks emerge fully feathered and well developed. They generally spend fewer than 48 hours at the nest site, during which time they are not fed. By the second or third night, the parents coax the chicks away from the nest site, then fly out to sea, leaving the chicks to find their own way to the ocean. The chicks’ path often involves a daunting climb over rough terrain, and down steep, rocky slopes. Chicks have been seen leaping from cliffs as high as 200 feet into the waters below. Once in the ocean, the chicks find their parents, who wait beyond the surf, calling for them constantly. Reunited, adults and chicks swim out to sea, where the parents continue to tend to the chicks for several months.

Cool Facts: This murrelet comes ashore only to breed, remaining at sea the rest of the year. This species together with the Scripps's Murrelet were considered conspecific and were known collectively as Xantus's Murrelet until 2012. Enough evidence was collected to consider both species distinct based on a lack of evidence of interbreeding where the both species nest together on the San Benito Islands, differences in facial pattern and bill shape, vocalizations and genetics.

Found in Songbird Remix Free Downloads Section under "33: Seabirds2"

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