Hello Sea birders, this is the trip report for June 14, 2015.
Thirty-nine birders and six leaders meet this morning for a 7 a.m. departure. This was somewhat later than the usual cast-off to avoid conflicting with fishing boat arrivals and departures. We got off right on time with a 6:59 cast off.
Trip leaders were Peter Ginsburg, Paul Lehman, Gary Nunn, Bruce Rideout, BJ Stacey, and myself. Paul gave the onboard orientation, did the wheel house direction, and the P.A. Bruce kept the e-bird list, and BJ did the lion’s share of the chumming. BJ, Gary, and Bruce did trip photos. All of us did our best to spot and direct birders to views of the birds.
The weather was as near perfect as anyone looking for comfort at sea could hope. Heavy overcast – in fact we had a few spells of light mist. The dark sky really works very well for spotting most all of the dark seabirds. Winds were very light: No more than 1-4 kts all day. Seas were benign, with a 1-2 ft. swell, and even though the swell came from two directions, the interval was long enough to avoid the roll that many land-lovers hate.
We generally have somewhat lower expectations for these late spring, very early summer trips. Wintering birds should be gone, the peak of migration is generally past, and post-breeding dispersal is often a few weeks away. So what does that leave? Well, most often, some surprises. That was true today! The sea surface temperature has been warmer than normal all winter, and even though it is much closer to normal now, an El Niño seems to be gain strength in the southern hemisphere. What will that mean for us today?
No more than a short distance into the main San Diego Bay channel we had a small number of “inshore” Bottle-nosed Dolphin. Though the population of this form is much smaller than the larger, darker, cousin found offshore, they are more frequently seen just outside the surf line along our beaches.
Our track out of the harbor took us past a number of points of interest: The bait docks for the many pelicans, cormorants, egrets, herons and sea lions, and past Ballast Point and Zuniga Jetty for a half dozen Surf Scoters – these being likely over summering birds, as many hundreds winter here and all but these few have long departed for breeding areas in the far north.
We then cleared the tip of Point Loma and its two lighthouses – the older atop the ridge dating to the 1850’s, the newer near the water line dating from the 1890’s. Near shore and the harbor entrance we found a mix of Brown Pelicans, Brandt’s and Double-crested Cormorants, Western and Heermann’s Gulls , and numerous Elegant Terns. The last two species recently arrived in big numbers from the breeding areas in the Sea of Cortez. Reports are of a largely failed breeding season there.
The area of ocean inside the Nine Mile Bank gave us a mix of Black-vented Shearwaters, a couple of Sooty Shearwaters, a few Black Storm-Petrels, Cassin’s Auklets, and many more Elegant Terns. We also picked up our first Brown Booby. This bird was an immature, a mostly dark bellied bird. Though Brown Boobies are now regular on local pelagics, they still elicit some excitement among sea birders. As the day went along and the booby count increased the excitement faded. So by the late afternoon, when 5-6 Brown Boobies were seen circling a fishing boat near the Thirty Mile Bank, they hardly drew a second look. Twenty-three Brown Boobies were listed for the day! I saw only 3 adults for the day, a mostly mature male, and two adult females.
The Nine Mile Bank had much the same birds, with the mix starting to change – more Sooties, fewer Black-vented Shearwaters, more Black Storm-Petrels and Cassin’s Auklets, and a distant Pink-footed Shearwater. We also ran into our first murrelets. Now, having “learned our lesson” last year when an exceptionally early pair of Craveri’s Murrelets showed up, we felt a careful study was appropriate. Mid-June we still expect to see the locally breeding Scripps’s Murrelets, not the later arriving Craveri’s. It took a while to get keyed in on the subtle differences, but we did have both species for the day. To increase the difficulty, most of the Craveri’s and some of the Scripps’s were missing flight feathers. Under normal conditions, these two species are separated by season. Scripps’s Murrelets arrive here in March, breed locally, and move out to the northwest by the end of June. Craveri’s Murrelets breed on islands and rocks off the southern portion of Baja California and the Sea of Cortez. In years when they arrive here (not every year), we’d see them In August and Sept. They are fully capable of flight then, and are I.D.’d (called) with some confidence. Both species have to be separated from Guadalupe Murrelet (not seen today), which may bridge the seasons of the other two. Guadalupe Murrelets are usually seen much further offshore locally. Until a few years ago, Scripps’s and Guadalupe were considered northern and southern races of Xantus’s Murrelet. The Guadalupe is actually somewhat easier to I.D. than the other two, as the amount of white in the face is greater and loops up in front and over the eye. Scripps’s and Craveri’s are a different problem. Scripps’s has a little more white in the face, with the white on the same line as the bill, and may show a brighter white eye crescent. Craveri’s is darker faced, with the dark extending very slightly below the line of the bill, and the white crest above the eye is faint or absent. Scripps’s sits a little higher in the water and may show a little white below the folded wing while Craveri’s is dark to the water line. The dark feather area of Craveri’s tend to be blacker, particularly on the head and neck. That area is slightly browner on Scripps’s. The bill is slightly longer and thinner on Craveri’s, shorter and thicker on Scripps’s. The characters most people look for on Craveri’s are the dark wing lining and breast spur, both hard to see with birds on the water. These field marks are better seen and photographed with the bird in flight. Size is also a factor, but dang if I can tell that Craveri’s is about an inch smaller in length than the less-than-10-inch long Scripps’s.
So ….what did we see and when…? The first solo bird appears to have been a Craveri’s and the next group of five were I.D.’d as Scripps’s, as was the next solo bird. The next group of 4 was all Craveri’s, as was the next group of 5. One pair with a chick were Scripps’s, and so it went for 10 Scripps’s Murrelets, and 20 Craveri’s Murrelets for the day. Thanks to all the photographers for the many excellent pictures, they helped a lot. These Craveri’s Murrelet were clearly early arrivals and may continue up the coast as the summer proceeds.
We departed the north end of the Nine Mile Bank and drove west toward the Thirty Mile Bank. The intervening area, known as the San Diego Trough, can be a dead zone, but promptly gave us surprise number two – a Buller’s Shearwater, a rare but regular fall migrant inside San Clemente Is. As most Buller’s Shearwaters pass through the Hawaiian Islands on the northward migration, they are barely recorded here in spring. No sooner had Paul explained that than the second Buller’s showed up. So we had two in view at the same time. Then as the day went along we added a third and fourth, and ended the day with a very conservative 17, for a bird that maybe had a couple of previous spring records here.
Mid Trough we heard someone call a sea turtle off the bow, then as quickly, a South Polar Skua was called off the stern. The South Polar Skua was obliging and flew right over the stern of the boat, then attacked a Western Gull out of sheer orneriness, or is it just what South Polar Skuas do? Meanwhile, the sea turtle also popped up in the wake just off the stern and a few quick-on-the-trigger camera folks got photos of what later proved to be a Loggerhead Sea Turtle. All sea turtles are rare this far north, so this was a nice addition to the day’s rarities. This animal was about the size of a large trash can lid, and had a number large gooseneck barnacles on the upper shell.
This mid Trough area also had a number of schools of crashing tuna. Doug Aguillard’s quick camera work got a nice shot of a Yellowfin Tuna breaking the surface – another out of season warm-water species. As we approached the Thirty Mile Bank the number of storm-petrels increased. Black Storm-Petrel is the default storm-petrel in all are local areas, and we had scattered birds all day once offshore and away from the beach. We did pick up a few Ashy Storm-Petrels, but it was a white-rumped bird here on the Thirty Mile Bank that got our attention. The logical assumption would have been a Leach’s Storm-Petrel, and one was seen on the day. Our local race of Leach’s Storm-Petrel, chapmani, often has an all-dark rump, or with just a smudge of white to the sides of the rump. Or, if the rump is all white, is divided in the center – not the bold solid-white rump seen here. Also, the flight style was all wrong for Leach’s. Leach’s Storm-Petrel, both leucorhoa and chapmani, have that bounding, slightly crazy, twisting turning, high wing-stroke flight. This bird had more of a short fluttery flight style. There is a race of Leach’s Storm-Petrel, socorroensis, that breeds on Guadalupe Is. some 200 n.m. south of here, which some think may be a separate species called Townsend’s Storm-Petrel. The flight style fit – Townsend’s show the more fluttery flight style, appear shorter winged, often (but not always) have a bright white rump, limited to the top of the rump only. The problem here was that the bird we were looking at was in heavy molt. One would expect Townsend’s to be in a high state of breeding plumage, and of course be closer to their breeding island. Again the photographers came to the rescue. Multiple photos showed the white wrapping around under the tail, a short square-ish tail, and more importantly, a long legged bird. This was a Wilson’s Storm-Petrel! A somewhat regular, though rare, species here, expected in early fall…., but spring??? Wilson’s Storm-Petrel surprise number three!
We drove down the inner escarpment of the bank to the border before turning east, back out over the Trough. The next interesting sighting was of a couple (maybe 3 ?) Blue Whales. Nice looks. The Blue Whale populations have had problems worldwide. The Southern California Bight has remained a stronghold, with more than five hundred Blue Whales counted by aerial survey, mostly around the northern Channel Islands, but also a fair number off San Diego.
The return to the outer edge of the Nine Mile Bank added to the Buller’s Shearwater, Brown Booby, and Black Storm-Petrel counts. We also picked up a fairly steady flow of Pink-footed and Sooty Shearwaters – both southern hemisphere breeders that spend their winter, our summer, in the California Current, and spread into a wide front along the west coast of North America. With enough practice, all four species of shearwaters seen today can be separated by flight style. The Black-vented Shearwaters have the snappy, very rapid, 4 or 5 wing beats, a very short glide, back to the rapid wing beats, then another short glide. Sooty Shearwater has a rapid wing beat and a little longer glide, often with the wing beats continuing as the bird is on a slight rise, followed by a glide on a sight descent, which is accentuated if there is more wind. Pink-footed Shearwaters have a slower wing beat, but still with a little snap, and an even longer glide. Buller’s Shearwater has the most languid wing beat, and an extensive glide even light wind conditions. It’s fun to test your skills when all are present in numbers, as they were today. Just recognize that as the winds change, so will the flight styles.
The return across the Nine Mile Bank showed we weren’t quite done with the surprises. We got good looks at a very small, short tailed, large winged storm-petrel with a nearby Black Storm-Petrel. Now if it had been August or September, I don’t think we would have hesitated to call a Least Storm-Petrel, tick it off the day’s list, and continue, but this is mid June?? Fortunately, the photographers helped us out again. In fact, there was another photo taken some hours earlier of a Least Storm-Petrel, so two were seen today. A subsequent trip four days after this one, on June 18th, looked to prove the continuing presence of Least Storm-Petrels, and found six.
The return to the harbor gave us good looks at a Rhinoceros Auklet and a Red-necked Phalarope, both out of season, but neither particularly rare. We also had some nice looks at Least Terns just off the Point.
We returned to the Grande slip at 7 p.m., tired but successful. Our thanks to owner and Captain James McDaniels, Captains Jimmy and Charlie, and deck hand and cook Oscar for another great day on the water.
Species list:
Mallard *
Surf Scoter * 6
Pink-footed Shearwater
Buller’s Shearwater 17
Sooty Shearwater
Black-vented Shearwater
Wilson’s Storm-Petrel
Leach’s Storm-Petrel
Ashy Storm-Petrel
Least Storm-Petrel 2
Brown Booby 23
Brandt’s Cormorant
Double-crested Cormorant
Brown Pelican
Great Blue Heron *
Great Egret *
Snowy Egret *
Black-crowned Night-Heron
Red-necked Phalarope 1
South Polar Skua
Scripps’s Murrelet
Craveri’s Murrelet 20
Cassin’s Auklet
Rhinoceros Auklet 4
Heermann’s Gull
Western Gull
Least Tern
Caspian Tern
Common Tern
Elegant Tern
Rock Pigeon *
Barn Swallow (1 on the 30 Mile Bankplus several seen on San Diego Bay).
* Seen on San Diego Bay only
Mammals
Blue Whale
Bottle-nosed Dolphin (inshore)*
Bottle-nosed Dolphin (offshore)
Common Dolphin sp. (some Long-beaked)
California Sea Lion
Reptiles
Loggerhead Sea Turtle
Fish
shark sp.
Mola mola
Pacific Bonito
Yellowfin Tuna
Insect
Dragonfly sp.
Dave Povey
www.sandiegopelagics.com or socalbirding.com
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