On Saturday, the 25th, we (SubSea Tours out of Morro Bay) ran four whale watch trips and two private charters in the ocean waters off Morro Bay. The sea was calm all day. On all trips we saw several humpback whales lunge-feeding and engaging in other showy behaviors within a few miles of the Morro Bay harbor mouth.
Along with the whales was an immense flock of Sooty Shearwaters, resembling a swarm of insects and at times a hurricane, as the birds flew in wide circles searching for food. There must have been several hundred thousand birds, and perhaps nearly a million. In years past, I have seen flocks of this species numbering in the tens of thousands, and at another time a living river of them that I estimated at 110,000 but this is the largest single flock of this bird (or any bird species) I have ever seen. Indeed, the migration of Sooty Shearwaters, though it is not widely known, ranks as one of the great wildlife migrations in the world. Other species of shearwaters, and sometimes other seabirds, associate with these mass migrations and feeding stopovers. Along with them were Brown Pelicans, multiple species of gulls, and other seabirds more commonly seen off our coast, such as Common Murre, Brandt's Cormorant, and Red-necked Phalarope. On one trip we saw bottlenose dolphins riding the bow wave of the boat as well.
Many people have also reported seeing similar phenomena off Avila Beach, Shell Beach, at the Pismo pier, and other coastal locations in the last several days to a week or more. The SLO Tribune reported crowds of people going to Avila Beach to observe wildlife from shore on Friday. I hope many of you had the opportunity to see it.
Also on Saturday, while leading a kayak excursion inside the bay, we observed a large number of Caspian Terns plunge-diving. There were also White Pelicans on shore, Marbled Godwits, two species of egrets, and others including Double-crested Cormorants and multiple gull species.
On Sunday we ran five whale-watching trips to take advantage of the proximity of all this wildlife. Humpback whales and shearwaters (these in smaller but still impressive numbers) were still close to the Morro Bay harbor mouth. Whales were breaching, lobtailing, slapping the water with their long flippers, and engaging in other show-off behavior. Birds were very active. By afternoon, all species began to move farther offshore and away from the harbor entrance, presumably because they had begun to deplete their prey of schooling fish (sardines, anchovies, etc.), shrimp, other crustaceans, and whatever else was in the water that was nutritious for them. Also the wind began to pick up in the afternoon, the ocean became rougher, and by the late afternoon and evening trips, there were fresh breezes (16-20 knots) and many whitecaps, making it more difficult both to spot whales and to close the distance to them.
This underscores the fact that these phenomena are Transient Wildlife Spectacles, a non-technical term I coin for them here. In this way, they are similar to the feeding frenzies of birds and marine mammals that occur in Morro Bay, in ocean waters off the coast, and elsewhere. If one wants to observe these first-hand, it is necessary to get information quickly and go where they are happening without delay. In some cases, these events may last for several hours or even a few days, but in others they may last only an hour or so, or even less. Avid birders know that if they want to spot a rare bird that shows up in an unexpected place, they must go there as soon as the occurrence is reported or risk missing the opportunity.
At any rate, the great spectacle had dissipated and moved offshore as of Sunday evening, but it could recur. Please keep your eyes open and send out reports if it does.
