Re: Probable Masked Booby on Sutil Rock

Bernardo Alps

Hi all.

Upon closer examination, Mark Stacy found a second, probable Masked Booby, in his photos. The bird we identified at great distance from Signal Peak was an adult, and the second bird in his photo is a sub-adult, most likely the same sub-adult bird seen from a closer distance in the afternoon. 

Here are the eBird checklists that contain photos of the boobies. I am convinced that they are all Masked Boobies, I am just calling them Masked/Nazca out of an overabundance of caution.

Take care,


On Mon, Aug 26, 2019 at 5:54 PM Bernardo Alps <whalephoto@...> wrote:

Hi all.


We went to Santa Barbara and Catalina Islands over the weekend aboard the Magician out of 22nd Street Landing in San Pedro. The trip left late Friday night and we awoke at anchor at Santa Barbara Island. Normally we would have stayed a second night, but an increasing groundswell generated by tropical storm Ivo made us relocate to Parson's Landing on the northwest side of Catalina Island.


During a Saturday morning island hike, we surveyed Sutil Rock from Signal Peak. Mark Stacy spotted a near-adult Masked (possibly Nazca) Booby among the roughly two dozen Brown Boobies visible perched on the cliffs. The Magician got close to the rock after circumnavigating the island during our late afternoon departure. We were able to count approximately 70 Brown Boobies and got better looks at the Masked Booby. My photos show a greenish-yellow bill but I would have liked slightly better quality to be absolutely sure. 


On our return trip from Catalina Island Sunday afternoon, we had an adult Masked Booby fly by at about 125 meters from the boat. We came away with the impression of a yellow rather than orange bill but were not willing to rule out Nazca. Later, a post on Facebook by Gregg Gentry showed a pair of nice close-up photos of what must have been the same bird since we saw the whale watching boat nearby just before we spotted the booby coming from its direction. 


In conclusion, both birds are almost certainly Masked Boobies but I am reluctant to make it an absolute. 


The Horned Larks seem to have had a very good nesting season; there were flocks flying all over the island. We saw only a couple of straggler Pigeon Guillemots. The only two possible migrants were a Common Yellowthroat and an American Kestrel. The canyon above Parson’s Landing was very birdy but there was nothing unexpected.


We encountered very few seabirds during the crossings. Between Santa Barabara and Catalina Islands, we had 1 Cassin's Auklet, 1 Ashy Storm-petrel, 10 Pink-footed Shearwaters, 4 Sooty Shearwaters, and 3 Black-vented Shearwaters, in addition to a few dozen Western Gulls and a couple each of Double-crested Cormorants and Brown Pelicans.


On the crossing from Catalina to the mainland, we had 4 Pink-footed Shearwaters, 7 Black-vented Shearwaters, 2 Red-necked Phalaropes, 1 Pomarine Jaeger, and 1 California Gull, in addition to a few Western Gulls and Elegant Terns, plus 1 Royal Tern and 1 Barn Swallow.


The next two-day Santa Barbara Island excursion is scheduled for September 25 and 26. More information can be found at

Take care,





Bernardo Alps
Wildlife Biologist

California Whales & Wildlife
P.O. Box 1667
San Pedro, CA 90733


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