Family Auks (Alcidae)


Guadalupe Murrelet (Synthliboramphus hypoleucus)


French: Guillemot de Xantus German: Lummenalk Spanish: Mérgulo de la Guadalupe
Other common names: Xantus's Murrelet (when lumped with S. scrippsi)

Brachyramphus hypoleucus


, 1860,

Cape San Lucas, Baja California


Sometimes placed in Brachyramphus or in Endomychura. Sympatric (as is S. scrippsi) with closely related S. craveri at San Benito Is (Baja California), where further study required in order to determine degree of mixing and gene exchange; may be conspecific with S. craveri. Often considered conspecific with S. scrippsi. Proposed race pontilis considered untenable. Monotypic.


Offshore rocks and islands of NW Baja California (San Benito Is, Guadalupe I); status on San Martín I, Baja California, and San Clemente I and Santa Barbara I (Channel Is), off S California, uncertain#R#R. Winters offshore presumably within the breeding range along the Pacific coast of Baja California, rarely further north.

Descriptive notes

23–25 cm; mean 130–185 g; wingspan c. 40 cm. Small auk with short, slender black bill; black upperparts with faint greyish cast, including top of head, neck, back... read more


No known differences from S. scrippsi.


Offshore and along sea coasts, occupying warmer waters than all alcids except S. craveri... read more

Food and feeding

Not well studied, but no known differences from S. scrippsi.


Very poorly known compared to S. scrippsi. Appears on sea near colonies mid- to late Dec, and breeding can continue until Jul.... read more


Post-breeding dispersal from nesting islands is largely offshore to W, and to N; individual pairs... read more

Status and conservation

ENDANGERED. Total population estimated at 5000 breeding birds, on the three San Benito Is, Guadalupe I and at least two associated offshore rocks. The relative numbers of... read more

Recommended citation

Nettleship, D.N. & Kirwan, G.M. (2019). Guadalupe Murrelet (Synthliboramphus hypoleucus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 22 January 2019).