- Research & Education
- Cape Cod
The first half of July has offered good birdwatching conditions. It has been relatively clear and calm for most of the time. Birders taking part in Wednesday birding discussions have brought a fair amount of seabirding experience with them and this always makes for a better experience on the water. The more eyes looking the more we find. This is important as the seabirds we watched were often scattered over distances though large tight flocks were occasionally seen between Race Point Canal and the area off the southeastern corner of Stellwagen Bank.
We had several occasions where Wilson’s Storm-Petrels were seen by the hundreds. When watching these storm-petrels look low over the water and look carefully as these small brownish-black with a white rump-patch birds can be tough to spot in the distance. Watch for them flitting back and forth or patting the water’s surface to stir up copepods. These flocks have generally been in the whalewatching areas to the southeast of Stellwagen.
Shearwaters are regularly spotted, at least as groups, in the Race Point Canal area to the north of Peaked Hill. As with most years Greater and Sooty Shearwaters are the vast majority. We’ve had some Manx Shearwaters as well but those are never seen in large numbers like the Greaters and Sootys. My first good looks at a Cory’s Shearwater came on July 7th. We have yet to see any big groups of these though there are many years that we see Cory’s infrequently at all. They generally stay a bit farther south and offshore. That we are seeing them at all is good!!!
Watch for the jaegers as well. My first good looks at a Pomarine Jaeger came on July 11th as we cruised north of Peaked Hill. The larger size, more stocky appearance, and more fluid wing-beats will distinguish the Pomarines from the Parasitic Jaegers. The jaegers should be here throughout the remainder of the season.
Certainly the best sight of these two weeks was a South Polar Skua on July 15th as we waited for some humpback whales to surface. GREAT but quick looks though not great photos. At 21 inches with a 52 inch wingspan these skuas are noticeably larger and a pound heavier than Pomarines. We would generally get juvenile migrants as the adults spend their non-breeding season much closer to their Antarctic breeding grounds. They are a cold and light to medium gray color with striking white bars on the outer wings. Great Skuas, not usually seen for another month, would be a more noticeable reddish brown. Several primaries were missing on this bird as South Polar Skuas molt larger numbers of primaries at once. This is often considered a reliable field identifier.
This South Polar Skua flew quite close to the boat and some 30 feet above the water’s surface. It circled once and then flew off in a southerly direction. Though less adept at kleptoparasitism than other skuas or jaegers South Polar Skuas will occasionally go after gulls or shearwaters. They prefer plunge diving for fish (or krill in the Southern Ocean).
Making this sighting particularly noteworthy are two considerations. First, except for Arctic Terns, South Polar Skuas (at least the juveniles) have the longest migration of any birds. Those that we see here migrate from the Antarctic Peninsula up the east coast of the Americas to southeastern and southwestern Greenland. Then they move on toward west central Africa and then back to Antarctica. Second, those South Polar Skuas migrating into the Atlantic may number as few as 660 pairs. With these considerations ANY sight of a South Polar Skua here is a blessing!!!