A fine way to start the morning. This is 5th of 6 Short-tailed Albatross seen on the trip. The 6th came just 45 minutes later but was a bit too wily to photograph.
Twenty foot seas are gone–today the sea was a mirror. The feather detail of this molting Short-tailed Shearwater is clearer in the reflection than it is on the bird!
The first few days at sea have been great. Our departure from Dutch Harbor on July 21st was met with 4o knot winds and 15-20 foot seas, not the best birding conditions, even on a 209 foot ship. Despite the conditions I was able to snap off a few marginal photos of this Mottled Petrel just north of Unimak Pass in the large swells. Mottled Petrel is the only Pterodroma expected in Alaskan waters. It is first picked out by its fast and arching flight and then identified by its shape, sharply patterned back and underwing, and its dingy-gray belly; it is the only Pterodroma to show this gray belly. Normally you see Mottled Petrels for about three seconds as they flash by, however, with the very strong winds several of the birds, including the bird in these photos, cruised along side the ship for several minutes. We saw four Mottled Petrels on the first night out and at least eight the next morning within 45 miles of Unimak Pass.
This evening, July 23rd, things got even better–even the weather! While transiting over Zhemchug Canyon on the Bering shelf (about 180 miles west-northwest of St. Paul Island) under calm winds and seas we found two Short-tailed Albatross–a dark brown juvenile and a paler sub-adult bird. The juvenile is photographed here.
The ship moved into Bristol Bay a few days ago where the highlight has been an early Sabine’s Gull on 28 April. The bird numbers dropped dramatically after we left the deep waters west of Bering Canyon and entered the shallower waters of Bristol Bay. However, the last two days transiting deep water (26-27 April) were great and produced 2 more Mottled Petrels and 2 Leach’s Storm-Petrels–both of which are exclusively found over deep water. We also recorded 4 Red-legged Kittiwakes on this transit. There have been nice numbers of Short-tailed Shearwaters, both over deep water and in the shallower waters of Bristol Bay. Many of the shearwaters have been occurring in tight flocks of 30-50. Watching Short-tailed Shearwaters maneuver in a 30 knot wind is about as good as it gets!
When compared to the similar Sooty Shearwater, note the steep forehead and shorter, thinner bill of the Short-tailed. Contrary to popular belief the “underwing flash” of a Sooty is not a reliable field mark for separating the two species. Short-tailed Shearwaters can show a flashy underwing (see top photo), especially when seen in bright light as these birds were. On a Sooty Shearwater, however, the brightest part of the underwing is the underwing covert panel and these bright underwing coverts contrast with the bird’s darker flight feathers. The underwing of a Short-tailed Shearwater is more uniform and can range in coloration from dark to light. When Short-tailed Shearwaters show a pale underwing it is a uniformly pale, or “flashy,” underwing and the flight feathers, especially the primaries, are also pale. In the top photo of the two Short-tailed Shearwaters note how the paleness of the underwing extends onto the primaries, which don’t contrast with the under-primary coverts as they would in a Sooty. Structural clues and flight styles are also extremely important, especially when the two species are seen together.
Click here for an excellent article (with excellent photos) by Greg Gillson, published in Birding magazine, which details the seperation of these two species.
Here are a few shots from the first few days at sea on the Oscar Dyson. If you’re curious you can view the ship’s current location and route by going to the NOAA ship tracker page and selecting the Oscar Dyson from the list of ships on the right sidebar.
We spent much of yesterday in Amukta Pass, a broad pass of open water between Amukta and Seguam Islands. Occurring about 200 miles west of Dutch Harbor it is the western extent of the ship’s route on the ship tracker web page. The seas have been relatively calm and the birding has been great. Highlights from yesterday and today include an early Pomarine Jaegar, 10 species of alcids and 6 of tubenoses, including 3 Mottled Petrels. Unfortunately the petrels didn’t pause long enough for a photo.
