It’s been a wonderful week at the Cove, with a once-in-a-lifetime show of sooty shearwaters and black storm-petrels.
I’ve spent nearly the entire day every day there staring through my scope. My eyes no longer focus anywhere except on the horizon…
But I’m posting to let people know that the spectacle is over.
Paul L. and other have posted maximum numbers.
I differ on only one of those: my count of sooty shearwaters on Friday May 17 was greater than the 20,000 several others have reported, but even 20K is by far the largest number ever seen in a day in San Diego County.
Numbers of black storm-petrels grew rapidly from the time they were first reported 10 days or so ago. They were very difficult to count most days because they were moving so constantly and were spread out across the ocean as far as one could see. I could count only those within maybe 1 or 1.5 miles, but still see swarms of them feeding over the depths of the canyon, 2 or more miles away.
Numbers built up to a peak of probably somewhere just shy of 2000 on May 22.
Whatever they were feeding on—and I think it was pelagic red crab eggs—attracted numerous other birds, including for several days between 75-90+ least terns.
However, yesterday, when I spent only a measly 6 hours seawatching beginning at 10:30 [so I missed the crucial first 4 hours of daylight], I began seeing the storm-petrels leaving the Cove and moving south in large numbers.
Over the 6 hours, with a lunch break in the middle, I counted around 1400 doing that. Maybe 250 or so were left in the Cove when I gave up at 6:00 pm.
I saw no least terns, and very few other birds feeding inshore.
Whatever food they were eating must be gone.
Today I got to the Cove mid-afternoon.
I counted about 30–40 black-storm petrels. As the afternoon progressed, they began moving south.
I wouldn’t be surprised to find none or only a handful in the Cove Saturday morning.
Sooty shearwaters are still moving past in small numbers, about 100/hour, but mostly far offshore except for the first hour or so after dawn.
A handful of black-vented shearwaters are still around.
Stan Walens, San Diego
May 24, 2019; 11:00 pm
Source: SanDiegoRegionBirding Latest Reports