Saturday, September 28, 2013

Blue-footed Booby Invasion Finds The Farallones

On August 25th, some tourists visiting the east side of the Sierras took a photograph of a strange bird on the shoreline of Mono Lake. Later that day, they showed it to Max Henkels, an intern who was leading a bird walk for the Mono Lake Committee. He immediately recognized the bird in the photograph as a Blue-footed Booby. He was likely very excited, as this species had never been recorded at Mono Lake. Unfortunately, the bird was never re-found by Max or any other birders or biologists. The tourists then left town without leaving any contact info and the photo was lost. However, this story was only the first of a series of Blue-footed Booby sightings in California this year. An unprecedented number of Blue-foots have shown up all over the state since this first individual was spotted at Mono Lake.

Over the next several weeks, dozens of Blue-footed Boobies were reported from coastal and inland Southern California. By September 11th, they had reached Northern California. A single bird was spotted by birders Mark Butler and Roger Harshaw at the Point Reyes Lighthouse; and in the following days there were sightings from San Mateo, San Francisco, Marin, and Sonoma Counties. Astoundingly, a single bird was found all the way up in British Colombia! On the Farallones, it was only a matter of time before one showed up here.



A map showing the locations of all Blue-footed Boobies reported to eBird so far in 2013.

Finally, on September 18th, a call came over the handheld radios on Southeast Farallon Island that a Blue-footed Booby was perched on the western edge of Saddle Rock. Moments later, everyone on the island was peering intently through binoculars, cameras, and spotting scopes at the Farallon's first ever Blue-footed Booby. The juvenile bird preened nonchalantly before taking a short flight and landing back on the rock, never suspecting how special the humans on shore considered it to be. It was quite a relief for us to finally see one after reading so many reports from the mainland.


The first Farallon record, pictured here, had a thin white stripe down the center of its tail, making it distinguishable from the rest of the Boobies to follow.


The second Farallon Blue-footed Booby showed up in the same place on the west end of Saddle Rock, an islet off the south end of our main island. The central tail feathers on this bird are dark, showing a different pattern from the first bird.

Cameron snapped off a few shots of this third Island Record Blue-footed Booby as it flew in during his sea watch. The longer central tail feathers (rectrices) distinguished this bird from the previous two individuals.

Can you spot the Booby amongst the Brandt's Cormorants? We are currently trying to determine if this booby is the same individual pictured above, in flight.

One more of Cameron's shots of the 3rd (or possibly 4th) Farallon Blue-footed Booby.

The California Bird Records Committee's publication Rare Birds of California tells us that Blue-footed Boobies breed in the tropical Eastern Pacific Ocean. Off their breeding colonies, they can be found anywhere from Baja California to Chile. However, they are known to periodically irrupt north into California and Arizona between July and October, during their post-breeding dispersal. During these irruptions, there have been relatively few records from coastal California. The bulk of the sightings (7 of every 8) have typically occurred many miles inland, at the Salton Sea, not far from the Mexican border and their breeding grounds in the Gulf of California. For example, in 1972 a flock of about 40 Blue-footed Boobies was seen at the north end of the Salton Sea at the Whitewater River delta. Prior to 2013, it had been over 30 years since the last irruption, which was minuscule in comparison. This time around, Boobies have been detected in at least 15 California counties, as well as Arizona and New Mexico, not to mention in much larger numbers. 


 On 24 September, Oscar Johnson made a conservative high count of 26 Blue-footed Boobies at the south end of the Salton Sea. How many of them can you see in his photo above? The next day, birder Dave Goodward saw 47 at the Whitewater River delta! This was the highest count ever recorded in California for Blue-footed Boobies.

The Farallon bird marked the fifth Sulid species to occur on this island, since biologists began keeping track of such things in 1967. Sulids, or members of the family Sulidae, are large seabirds with long wings, wedge-shaped tails, and stout, conical bills. Sulidae is comprised of ten species of Boobies and Gannets in three genera, but only five have been seen in North America. Remarkably, all five of these species have now occurred on the Farallones. Northern Gannet, Red-footed, Brown, Masked, and now Blue-footed Booby have all been seen from this tiny rocky island.


Last year, the birding world was shocked when Farallon biologists located a Northern Gannet on the island. Not only was the Gannet a first Island Record, it was the first to ever be spotted in the Pacific Ocean. The Gannet has been sighted roosting at the island nearly everyday since, and it is still seen daily, roosting on Sugar Loaf. Check out the Gannet story by clicking here.


This is one of my many photographs of the Farallon Northern Gannet from Fall 2012. Hundreds of people have visited the island on tour boats to get a glimpse (or some photos) of this amazingly rare bird.


The name Booby comes from the Spanish word bobo ("stupid", "fool", or "clown") because the Blue-footed Booby is, like other seabirds, clumsy on land. They are also regarded as foolish for their apparent fearlessness of humans. Sailors thought them unintelligent due to their habit of landing on boats at sea, where they were easy prey and inevitably ended up in the hungry seamen's cook pots.


Here, a Brown Booby takes a free ride to the Farallones aboard a fishing boat during Fall 2012.

So if you are interested in seeing some Sulids for yourself, and you live in California, now is the time to get to some rocky coastline and scan for Blue-footed Boobies. After all, it may be 30 years before they come back.

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