Craveri's Murrelet

Synthliboramphus craveri

(c) Mike Danzenbaker, http://www.avesphoto.com
  • ALCIDAE
  • Auks, Murres, Puffins, Guillemots
  • Charadriiformes
  • Mérgulo de Craveri
  • Alque de Craveri
Appearance Description
At just 9 inches in length, Craveri's is the smallest of the murrelets. It is very similar in size and plumage to Xantus' Murrelet, which breeds further north along the Pacific coast of Mexico and California. Craveri's is black above and white below, with a dark, short, slender bill and short tail. Craveri's is darker overall than Xantus'. It also has a longer, thinner bill, and a gray, rather than pale, underwing. Both species have black on top of the head, with contrasting white cheeks, chin and throat; Craveri's has a cleaner, straight-lined separation between black and white on the face, while Xantus' often has white extending up in front of the eye. At rest on the water, Craveri's shows much less white on the breast and sides than Xantus' does. Distinguishing between the two species is not always possible away from their respective breeding grounds. Its voice is a high, shrill whistle or trill, sometimes given in a series.
Range Distribution
During the breeding season, this species is found primarily on islands and in nearby offshore waters of Baja California. Craveri's Murrelet ranges further south than any other alcid species, although it shares much of its range with Xantus's Murrelet and Cassin's Auklet. After breeding is complete for the year, Craveri's Murrelets disperse both north and south, expanding their range to the coasts of central California and western Mexico, perhaps as far south as Guatemala. Mexico's Isla San Pedro Martir Important Bird Area (IBA), and Isla San Pedro Nolasco IBA are two of at least 11 islands off Baja California that support breeding Craveri's Murrelets.
Habitat
This resident of warm, coastal waters only comes to shore during the breeding season, when it seeks out small arid coastal islands. A ground-nester, it requires rocky, vegetated coastal areas, where it builds its nest along cliffs, in crevices, or hidden among dense shrubs. Following the breeding season, the birds move out to sea for the autumn and winter months.
Feeding
Like all murrelets, Craveri's dives from the water's surface to capture its prey. It is a strong underwater swimmer, able to propel itself rapidly with its wings in pursuit of fish. Larval fish are the main food taken, especially rockfish, herring, and lanternfish.
Reproduction
A pelagic bird, Craveri's comes to shore to breed in colonies from spring until early summer. Two eggs are laid at night in a well-hidden depression, rocky crevice, or ground-burrow. Nothing is added to the "nest" – the eggs rest directly on the ground. The two pale eggs can be highly variable in both coloration and markings. Incubation lasts about a month, and both parents tend to the eggs. After hatching, the young, downy-feathered chicks are able to follow their parents to the sea within just two days! The first month at sea is dangerous for young Craveri's chicks; their survival rate during this time period is only 30-35%. After the nesting season, family groups disperse to off-shore waters.
Migration
Following the breeding season, birds disperse to both the north and south, along the Pacific coast and the eastern coast of Baja California. Birds occasionally wander up or down the Pacific coast, and have been noted far from their typical range.
  • 15,000 – 20,000
  • 15,000 – 20,000
Population Status Trends
Approximately 5000 breeding pairs nest within this species' very restricted range. There are as few as 10 islands in the Gulf of California with suitable habitat requirements for nesting. It may also nest at a few locations along the Pacific coast of Baja California. Craveri's Murrelet is in decline as a result of a number of human activities.
Conservation Issues
In 1995, a Biosphere Reserve was designated under UNESCO's Man and the Biosphere Programme that covers 124 islands in the Gulf of California. On this island group, named Islas del Golfo de California (Gulf of California Islands), numerous activities have taken place that benefit Craveri's, including the eradication of introduced mammals on islands known to support nesting Craveri's at some time and on potential breeding islands. Other activities have consisted of developing management plans for all known breeding islands, performing long-term monitoring of seabird nesting colonies, assessing the impact of recreational activities, environmental education, and erection of warning signposts on islands. Enforcement of existing regulations has also been increased. Additional measures to pursue could involve the monitoring of major populations, estimating population size, determining the impact of gill-net fisheries on the population, and controlling the amount of tourism on breeding islands.
What You Can Do
Island Conservation, a non-profit organization focused on restoring native seabirds and island ecosystems of Baja California and southern California, has many projects underway to remove introduced predators from islands.

To look for Craveri's Murrelet (and many other pelagic species), take a boat trip with the Los Angeles Audubon Society.

Find out about actions you can take including Audubon programs and activities.
More Information

Within Craveri's Murrelet's range, two of Mexico's Important Bird Areas (IBA), Isla San Pedro Martir and Isla San Pedro Nolasco, provide crucial habitat for this species. BirdLife's IBA program is an essential tool for the conservation of Craveri's Murrelet, as well as for other species. Learn about Audubon's IBA program.

Learn more about this species and other birds through these resources.

Natural History References
Bent, A. C. 1963. Life Histories of North American Diving Birds. Dover Publications, Inc., New York.
BirdLife International (2007) Species factsheet: Synthliboramphus craveri. Downloaded from http://www.birdlife.org on 30/8/2007

Harrison, P. 1983. Seabirds: an identification guide. Croom Helm Ltd., Kent, United Kingdom.

Sibley, D. A. 2000. The Sibley Guide to Birds. National Audubon Society, Alfred A. Knopf, New York.
Conservation Status References
BirdLife International (2007) Species factsheet: Synthliboramphus craveri. Downloaded from http://www.birdlife.org on 30/8/2007

Harrison, P. 1983. Seabirds: an identification guide. Croom Helm Ltd., Kent, United Kingdom.

Sibley, D. A. 2000. The Sibley Guide to Birds. National Audubon Society, Alfred A. Knopf, New York.