Alvaro's Adventures

Buller's Shearwater looking "spiffy"

This was a fantastic, yet unusual pelagic trip. We had great looks at the birds out there, and there was a lot to see, but the abundances were all askew. The most common shearwater was Buller’s! In fact all of the Sooty and Pink-footed we saw did not add up to the number of Buller’s we found! Then in the jaeger department, the Long-tailed was by far the most common jaeger. The second runner up Pomarine did not even come close in numbers! This trip was actually a very good study trip to learn the Long-tailed Jaeger as there were so many around.

For amazing photos of our trip by Luis Villablanca – click here.

Listening in to the dolphins with the hydrophone! Photo Tom Goodier.

Similarly we had a lot of Arctic Terns,  more than one usually sees on a pelagic as well as a Common Tern (which was a county bird for many on board). Apart from the birds, we did have some nice Humpback Whales, pretty close ones in fact! Then there were several pods of Pacific White-sided Dolphins, the last with some Northern Right Whale Dolphins. Here one of our intrepid participants lowered a hydrophone into the water for us to hear what the dolphins were saying to each other. It was pretty cool, with clicking and squealing sounds that are difficult to believe are made under water! Wow. Also a highlight was seeing a huge Ocean Sunfish (Mola mola), these fish get big, very big. In fact a Mola mola holds the record for the heaviest bony fish ever caught – at over 5000 pounds.

Photo by Tom Goodier - us on the boat!

The trip was overall quite diverse. There were Ashy Storm Petrels around, although no concentrated flock of them. The cold water was here, but only a few people glimpsed a Fork-tailed Storm Petrel, suggesting that the mini invasion we had of that species is now over. Similarly, Northern Fulmar numbers were down from what was about a couple of weeks ago. We did have a fly by Tufted Puffin, wished it could have stuck around for a better view, lots of Common Murres, Rhinoceros Auklets, and a few Cassin’s Auklets and Pigeon Guillemot (latter close to shore). A South Polar Skua was nice enough to fly by, and there were many Red-necked and smaller number of Red phalaropes. Weirdo birds offshore included Northern Pintail, Northern Shoveler, Eared Grebe(!), Short-billed Dowitchers, and a single juvenile Sanderling looking a little lost.

Immature Long-tailed Jaeger - a confusing looking bird, which could easily be misidentified. Likely a two year old.

Adult Long-tailed Jaeger with full streamers - off Half Moon Bay, California.

A little jaeger talk now. On left is a good looking adult Long-tailed Jaeger, with a nice long tail streamer. The bird has a bill that looks short and stubby, also there is a nice  neat, cap, no breast band and a slight yellowish wash on the neck. The wings are narrow, and the rear end is dark, contrasting with a white breast. A telltale feature, particularly at this angle, is that the secondaries are primaries are clearly darker than the rest of the upper wings. The bird on the right is a messy one, a much more difficult identification. However it is a Long-tailed, but pale speckling on the underwings (click on photo to enlarge), means it is not an adult, and that messy plumage on the underparts is typical of winter adults and immatures. Yet the bill is short and stumpy looking, the neat cap is there, and the wings are relatively narrow.

Pomarine Jaeger - immature

Now for the Pomarine Jaeger study. This one on the left outwardly looks adult like, and it even has the spoon-tipped central tail feathers. But, look at the underwings, they are not entirely dark but are barred with white. This means it is not an adult but a younger age. This may be a second or third year Pomarine, likely a second year bird. The shape is important to look at, it is thick at the breast and the belly; it just look thick-necked and pot-bellied and much heavier than the Long-tails. The cap is not as neat as on a Long-tailed, and it reaches down to the chin and throat. Also the yellow of the neck sides is brighter on a Pomarine, and the thick and long bill often looks to have a pale base. Both Pomarine and Parasitic Jaegers tend to have a breast band as adults and in immature plumages.

Pomarine Jaeger adult

Now this Pomarine on the left is an adult (I have other photos showing entirely dark underwings). It also looks thick necked, and rather short-tailed; a good Pomarine feature. The short-tailed look is one reason that Pomarine may resemble a South Polar Skua, it is not just the larger size of this jaeger. The bill is big, long and thick and here you can see it is paler at the base with a dark tip. The cap extending below the bill to the chin and sides of throat can be seen, and the relatively strong yellow wash on the neck sides. The white shaft streaks on the primary feathers are extensive on Pomarine, while Long-tails often just show 2-3, and no white on the feathers themselves, as this bird shows. The white on the rump is the start of the winter plumage.

Sabine's Gull - what a year it has been for this species.

This trip was also one of experimentation. I tried a couple of chumming “concoctions” and found out that they worked! Yippee. I need to fiddle some more to get the concoctions just right, but they were fishy and stinky enough to bring in a Wilson’s Storm-Petrel out of nowhere! This is the first time I have seen this species in California away from a storm-petrel flock. It also was essentially a new San Mateo species for almost all on board, which meant big smiles to those playing the county birding game. Glad to have been of assistance folks!

Wilson's Storm Petrel - a rarity in San Mateo County. As we do more pelagics here we will surely find out it is regular, but we are still in the discovery phase!

Apart from having a good time, seeing birds, county birding and just enjoying the ocean, some of what we see also has scientific relevance. For example numbers and distribution of the birds that are out there. But more directly, we often see color marked birds, particularly Black-footed Albatross. When we can see the band number, such as on the bird below, the information is all sent to the Bird Banding Lab, where this will go into the database which helps in albatross conservation. Albatrosses are under high risk due to long line fishing mortality, although in Hawaii (where this albatross breeds) they have been very good at decreasing incidental deaths. All the more reason that these data are helpful to Hawaiian Seabird conservationists. Speaking of conservation, it was great to have Matthew Mckown aboard, a seabird biologist from UC Santa Cruz, who chatted with many folks about the work he is doing monitoring seabirds with remote sensors.

Looking forward to our next adventure at sea! Alvaro.

Band on Black-footed Albatross