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Blue-Footed Boobies Glimpsed in Santa Cruz

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by Hilltromper staff

Sept. 18, 2013—A bizarre "invasion" of blue-footed boobies into southern California has extended up to Marin County in recent days, with at least four of the odd-looking seabirds spotted around Monterey Bay since Sunday.

Some 30 blue-footed boobies have been spotted in California since late last week, according to the LA Times. The rare visitation to points north includes a Santa Cruz County first, according to a posting on eBird.org. David Suddjian, a well-known local birder, reported having seen one on Monday, Sept. 16 at around 10:30am as he stood on the Capitola bluffs west of the Capitola Wharf. In his notes on eBird, Suddjian documents such features as white underparts and brown bars, concluding, "I think this was an immature bird, but maybe 2nd year?" In his notes he adds, "The combination of pale on the rump, white splotches of the back, pale lower neck, clean white underparts, white underwing pattern with a brown intrusion, and pale gray bill eliminated the other booby species." (Take that, doubters!)

See the eBird map of blue-footed booby sightings here.

Another local birder, Alex Rinkert, spotted two BFBs at Blacks Point on the Santa Cruz Eastside. Abe Borker reported on eBird that he saw one of those birds again yesterday evening at the same location.

Down in Monterey, the birds made a slightly earlier appearance, with a Brian Sullivan reporting on eBird that he saw one on Sunday afternoon. "Apparently this is the first record for Monterey County since 1971," Sullivan writes in his notes, "when another invasion of the species occurred." A birder named Cooper Scollan reports having seen three of them today around noon near Wharf #2.

The birds, which really do have bright blue feet from carotinoids in their diets, dive from heights as great as 300 feet to catch fish, according to the Wikipedia entry on blue-footed boobies. They generally inhabit tropical and subtropical waters off the Pacific Coast, where they eat sardines, anchovies, squid, offal, mackerel and flying fish—and constantly judge each other's health and fitness by the brightness of their feet. (Females who notice that their mate's feet have dulled—something that can happen within just a few days of skipped meals—start laying smaller eggs, according to one study cited, indicating they're unwilling to invest in an egg if the father is unhealthy and might not be around to raise the chicks.) A third to a half of breeding pairs nest on the Galapagos Islands. They seldom venture north of the Salton Sea—the last time anyone recalls was in the early 1970s—so they're a long way from home.

Whether the appearance of the boobies is linked to the anchovy population explosion in Monterey Bay is debatable. The LA Times reports that some experts are speculating that the birds are juveniles who have headed north in search of food following a blue-footed booby population explosion that has put pressure on the food supply in their normal range. One emaciated young bird found wandering the sidewalks of downtown Los Angeles (no joke) was taken to the International Bird Rescue Center in San Pedro, where it was gobbling up all the fish that came its way.

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