I’ve been gazing at a pair o
f boobies. Not that kind! I mean subtropical brown booby seabirds (Sula leucogaster) loafing on the bluffs and paddling in the sea in what I consider my territory. Mind you, I’m not a bird dog kind of dog.
Aeronautical wildlife like cawing crows drive me to distraction, and giant blimps (e.g., Blimpus metlifeii) scare me to barking bits (something must be done about those). However, the booby strikes my fancy maybe because it is historically a strictly south-of-the-border bird (be it from the Pacific side or the Sea of Cortez). Yet here it is fraternizing with seabirds on the north side of the border.
From a distance, the brown booby blends with the cliffside crowd because it kind of looks like a velvety cormorant bird. Nearer to, it more closely resembles a duck, maybe because of the tail feathers that drift upward, the low-slung muscular-looking body, the squat butter-yellow legs and large flipper feet, or the thickset neck and bill. Or maybe it’s the whole package. But all my “maybe” mullings don’t explain what the boobies are doing here.
Experts say that before the 1990s, brown boobies were exclusive to the Gulf of Mexico, and after then, a few might winter off the Pacific coast of Baja. So it was a shock when, in 2002, scientists came across six brown boobies (nesting no less!) all the way north at the Coronado Islands. Since then, more boobies have sojourned yearly to nest on the same rock. This spreading of wings and expanding of range led to sightings in Southern California, possibly due to our warming ocean (global climate change) or maybe they followed a food source. Whatever, their sky-blue eyes have been opened to the existence of previously unknown, yet suitable, real estate. Well, why not. Unlike us, they don’t need a passport. Still, they don’t wear a fur coat like I do, and feathers go only so far in the cold and damp so it takes some guts to fly the familiar coop, so to speak, to unknown climes.
To spot a dark-brown booby, look for birds sized in the 2-foot range, especially where crowlike cormorants congregate on the bluffs abutting the ocean. Though the booby is a powerful and agile flier, it is conspicuously clumsy on takeoffs and landings, which is why it likes steep locales to give it a boost. I wonder that being airborne-challenged may be a consequence of having a clunky ducklike deportment. Come to think of it, some bird watchers even report hearing an occasional sound similar to quacking from these typically silent birds. Once in the air, though, a booby showcases spectacular diving skills by plunging into the ocean at high speed (note the heavy-duty bill construction to withstand impact).
I watched one booby hunting for small fish (they’re really into squid, too). The bird mostly finned while bobbing on the surface, dipping its head under to scout for prey. My snorkel-swim buddy does the same thing (of course she’s only an observer) but, no surprise, I only dog paddle. Sometimes the booby completely disappeared under water, I figure, to give chase. After surfacing, I was impressed that it had traveled a good 15 feet. Finding food is hard work. I’m glad I have a kitchen that miraculously stays stocked.
Now that brown boobies are traveling farther north, will other subtropical species follow? In recent years, Southern California has also hosted blue-footed boobies, masked boobies, and the super-rare red-footed booby. It appears that avian tourists have already identified our region as a worthy, um, watering hole, and the trend is expected to continue (to include other typically subtropical seabirds). I'm prepared to get onboard with this situation (since I have no choice) but it would be a bonus if we could exile our Blimpus birds to Mexico.
Sydney the Golden Seal is a retriever-husky who has logged miles of ocean swims. She writes her column, “Sydney’s Ocean Log,” about the wonders of our watery world. When not dog paddling or opining, Sydney pursues archaeology research in her backyard. Write to Sydney using the Contact page, and put Sydney the Golden Seal in the Subject line.
— Judith Lea Garfield, naturalist and underwater photographer, has authored two natural history books about the underwater park off La Jolla Cove and La Jolla Shores. Send comments to jgarfield@ucsd.edu.