This is the trip report for the Buena Vista Audubon and Grande Sportfishing Pelagic Birding trip Sunday May 20, 2018. Forty-four passengers and six leaders meet in front of H & M landing for the 7 a.m. departure. H & M is a new landing for us and is a short walk to the right of our previous departure landing in San Diego Bay. H & M even shares the same parking lot. Today’s weather was a dense overcast, with nearly calm winds – excellent conditions for small alcid viewing. We could have done without the drizzle, but that’s often part of a spring pelagic.
Paul Lehman gave an orientation to the boat and it’s layout, a safety talk, and discussion of sea birding and how to locate seabirds once they are called out.
We were lead down the dock by Guy McCaskie, boarded Grande to be greeted by Peter Ginsburg, Justyn Stahl, Bruce Rideout, and Tom Blackman and once settled in, cast off for our adventure at sea.
The cruise down the bay was uneventful, but we did build a small list of the regular pelicans, cormorants, gulls, and all three large terns. We even picked up a few Black Skimmers. These are regular breeders in numbers at the far south end of the bay, but not as often seen here in the deep water of the north end. We drove down the buoy line in hopes of finding a resting Booby. No luck there, but we did get several nice looks a Brown Boobies further offshore. This once rare species locally has now become regular and expected. Brown Booby is a west coast of Mexico breeder and has expanded to the north and now breeds locally on the Coronado Islands and on some (one?) of the Channel Islands to our north. Though they are in somewhat lower numbers now from the peak years of 2014, 2015, and early 2016, we would be disappointed to miss them. Any other species of booby remains locally rare and would be an excellent find, though records of non-Brown Booby sightings seem on the upswing in recent years.
The biggest surprise, once away from the inshore waters, was the numbers of Scripps’s Murrelets. We got on several pairs right away. All adults. Scripps’s Murrelets are local breeders on the Coronado Islands and more pass through here on the way to breeding islands to the north. Most of the north bound movement comes here, or goes through here, in March (with a range of mid Feb. to early April). A few birds can have chicks with them by mid April, and most will have chicks by May and June. Seeing a pair of adults and no chicks by May 20th could indicate a late start to breeding or breeding failure by that pair. Today it was dozens and dozens of pairs of adult Scripps’s Murrelets scattered over most of the today’s route with no chicks that we could determine (chicks leave the nest at night 24-48 hours after hatching and go to sea unable to fly, so are attended by one or both adults). Both the chicks and attending adults dive to avoid predation, or large objects such as a boat full of birders. The Scripps’ Murrelets seen today seemed perfectly able to fly to escape. We counted some 120 plus today. Only a very few solo Scripps’s Murrelets were seen. Those might indicate a foraging bird with a mate in the nest burrow (these birds go on and off the islands at night to avoid gull predation) or perhaps a lost mate. So, the question of the day – why so many pairs of adult Scripps’s Murrelets so late in the breeding season with no chicks?? Did these birds fail to breed, did something on the islands cause them to abandon breeding there, is this a response to food sources, weather, sea temperatures, or other factors? I must say this seems concerning. I don’t recall anything like this occurring before. I ran through my notes and back through the 1980’s, the range of Scripps’s Murrelet sightings for the third week of May ranged from 0-47 birds. Mostly less than 15 per trip, but many with downy chicks noted! The June trip may give us additional insight on this subject. Scripps’s Murrelets are a local specialty, with a small population, and relatively few breeding locations, so always of some concern. OK, off my high horse, and back to this report.
We found a nice area of feeding Common Dolphin, Sooty Shearwaters, and Elegant Terns near the Mexican border and the inner Nine Mile Bank. This is so close to the border that we counted all three species in both countries. There was certainly a lot of food here in the form of very small baitfish. We did see a few Common Dolphins elsewhere today, but Sooty Shearwater was the most abundant species of the day (700-750) and scattered everywhere. Sooty Shearwater is a southern hemisphere breeder and world traveler over much of the Pacific Ocean to arrive in the food rich California Current. Most will continue far to our north before returning south to their islands around New Zealand and near the tip of South America. The Elegant Terns (450+) were also seen here and all the way out to thirty miles offshore. Most of these breed and travel to and from the salt works in south San Diego Bay. More breed on a few islands in the Sea of Cortez and those will increase the local population later this summer.
We did get a few other species here, including Black-vented Shearwater. This small white-bellied species is normally pretty regular near shore San Diego and seasonally somewhat regularly seen from the beach. This time of year most retreat to the breeding Islands off the Pacific Coast midway down the Baja Peninsula. The tiny Isla Natividad may have 90% plus of the worlds breeding Black-vented Shearwaters. This can be a tough time of year to count on seeing this species, so 24 today was nice as all observers got a look. The Black-vented Shearwater population seems to be a beneficiary of efforts by the Mexican Government to clear the breeding islands of non-native predators. We did have one other small white-bellied Shearwater seen a distance and passing quickly out on the 30 Mile Bank. Paul picked up on the bird and mentioned it, as its location was away from the normal inshore area. This shearwater seemed to have a brighter white and crisper dark pattern than expected for a Black-vent. Initial photos were inconclusive, but additional photos showed a white-saddled appearance, a little white curling up behind the ear, and perhaps the white under tail coverts of a Manx Shearwater – a common species on east coast pelagics, but decidedly rare here. That turned out to be the best bird of the day. It flashed by in the distance, was seen only by the few alert birders, and only proven later by photos. Pink-footed Shearwater was the other white-bellied shearwater seen today, which is another visitor from the southern hemisphere. These guys breed on islands off of Chile and come up into the California Current in our summer. Today we had less than two-dozen, but those numbers will build as we move into summer. Pink-footed Shearwaters are aggressive and not at all shy about approaching the boat over and over. I find it the most often photographed species on these trips.
Best photos of the day where of a young Black-footed Albatross. Not at all rare along the west coast, but relatively few come inside the islands of the Southern California Bight, so we are always happy to pick up that species on these trips. Black-footed Albatrosses breed on the westward Hawaiian Islands and actually have the smaller population of the two common North Pacific albatrosses. The Laysan Albatross is more abundant by a factor of two, and has a wider geographic spread to its breeding locations. These two albatross species seem to move to differing parts of the Pacific – Laysan more to the northwest, Black-footed Albatross to the northeast. At the other end of the size-scale from the large albatrosses were the numerous Black Storm-Petrels. These little tube-noses are ubiquitous once off the shallows of the Nine Mile Bank and are actually at the larger end of the scale for a storm-petrel. Black Storm-Petrels usually stay well away from the boat, out where size can be hard to judge accurately, sometimes giving one the look
of a shearwater. Their deep wing stroke and bounding flight look almost nighthawk-like. Black Storm-Petrel was likely the third or fourth most numerous species for the day (if Western Gull counted) with 250 or so seen. We did get some better looks as we returned to the Nine Mile Bank late in the afternoon.
The 30 Mile Bank had very few smaller and paler Ashy Storm-Petrels. Far less common but nevertheless regulars out here, they are even less boat friendly than Black Storm-Petrels. It takes a quick and discerning eye to pick up the smaller-winged, longer-tailed look, the shallower wing stroke, and more direct flight. This species is much sought after here, and often missed. We counted seven Ashy Storm-Petrels today. Several other species showed today, all with smaller numbers. We had maybe 20-25 Pacific Loons. These are northbound stragglers, likely young nonbreeding birds following the migration route of the breeding adults that have already passed through. Next, Red-necked Phalaropes, now mostly in alternate plumage, with maybe 70-75 for the day. This is actually a rather low number for this time of year. These are a small “shorebird” that feed by sitting on the water and picking at the surface. Red-necked Phalaropes today were typically in small groups of up to twenty.
Cassin’s Auklets were also in small numbers today. Notoriously hard to get on, not boat friendly, and often seen flying away in the distance. Cassin’s Auklets are close in size to Scripps’ Murrelets, but are mostly dark gray to the waterline, appear to have no neck, and can show a bit of a pale belly in flight. Where murrelets usually spring to the air like a puddle duck, Cassin’s Auklets require a running start from the surface, and if full of food may actually bounce off swells as they depart. Last, and one of the more beautiful seabirds, were Sabine’s Gulls. Not much larger than a tern and well-marked above by white, black, and gray triangles, this species breeds in the high arctic and winters off of South America in the Pacific Ocean.
Our return back to the Nine Mile Bank from the 30 Mile Bank was about as smooth a ride as we had all day. We did scare up a couple of seasonal oddities back in the birdy areas of the Nine. First was a rather washed out looking Northern Fulmar. These are sporadically regular in winter this far south. They breed in the Bering Sea and Aleutians. Usually, only the doomed Northern Fulmars straggle into late spring and early summer. Perhaps even more unusual for the season, though they breed as close as the central California Coast, was an alternate plumaged Common Murre. Most always a good bird off San Diego, this one was getting late. We also came on two different flights of Least Terns on the Nine MIle Bank. I’m always amazed at how far off shore these guys forage. They breed locally on sandy beaches and are believed to winter well offshore of Central America or even farther south. Last but not least (whoops), Paul Lehman mentioned that we might well see land birds once at sea, which is not uncommon on heavily overcast days, as we had today. Sure enough, we had maybe four or five passerine species for the day. Not all made it through the gulls following the boat, but those that did included a Pacific-slope Flycatcher and a couple of Warbling Vireos, Townsend’s Warblers, and Wilson’s Warblers. Lots of folks got photos of these guys on the deck between chairs, on rod holders, other birders heads, and we even had a couple ride in the wheelhouse with Captain James.
The Nine Mile Bank on the return gave us a nice Fin Whale show, with a least two and maybe three seen up close and personal for photos.
Bird species seen in San Diego Bay:
Great Blue Heron
Black-crowned Night- Heron
Bird species seen offshore:
California Sea Lion
Mola mola (Ocean Sunfish)
California Flying Fish