- Research & Education
- Cape Cod
John C. Conlon
If there was any doubt in my last birding notes as to whether autumn was here, that doubt is now gone. During these past weeks wind has come regularly from the northwest to north, and from the northeast. Summer pelagic bird numbers are dropping steadily. Even when birds are seen, the chop on the water’s surface combined with southeast swells from passing tropical storms make it difficult to hold the binoculars steady. The air is considerably cooler so hats and jackets are a good idea as are gloves for holding both the binoculars or the coffee mug while on the upper open deck.
Sightings have been good though they vary considerably. There are occasional sightings of phalaropes. Greater and Cory’s shearwaters, lower in numbers, are seen regularly as lone birds or in flocks of over 40. Those flocks are mixed and while the numbers are steady, you’ll want to be looking carefully as these shearwaters will soon be gone. The greaters migrate clockwise while the Cory’s migrate counterclockwise around the north Atlantic so their departures from the area will be in opposite directions.
Immature laughing gulls and black-legged kittiwakes are regular sights. Both are among the smallest gulls that we find locally so the size makes them easier to spot in the crowds. In particular look for the juveniles coming into first winter plumages. Black-legged kittiwake juveniles are easily recognizable with their black boomerang patch on the upper wings. The first year laughing gulls by contrast have blackened primaries, are brown on the secondary coverts and grey along the back with a white rump patch and black–tipped tail. Both are migratory, with the black-legged kittiwakes being common here in the winter, while the laughing gulls would not be expected during the winter.
Another sign of the coming autumn and winter are the scoters. Flocks of 15 to 30 white-winged scoters are common. Black and surf scoters are also arriving in small numbers. Watch for mixed flocks that may be flying low or high over the water. We will be seeing more scoters as the next month progresses. Many of the arriving sea ducks will be visible from shore, so birdwatchers can also return during the winter months.
Jaegers are back in larger numbers. Parasitic and pomarine jaegers are reappearing as they head south during their autumn migration. As always, look into the feeding flocks of gulls and terns. The jaegers are in pursuit of the gulls and terns that carry food. The most unusual sighting of these past three weeks was the 24th of September sighting of a long-tailed jaeger. They are rarest of jaegers to be found here and September is the best month to do so. Dolphin Fleet birding guide Peter Trull had a long-tail last year as well.
The long-tailed jaegers are the smallest jaeger at 15 inches in length (any adult breeding feathers of the central tail will put the length at 23 inches), 42 inches across the wings and averaging some 11 ounces. As with all the jaegers the females are larger than the males. Wingbeats are falcon-like suggesting parasitic rather than pomarine. At any distance long-tails will be quite grey in appearance. This coloring makes them easy to distinguish from both parasitics and pomarines. Look for the pale yellow of the neck’s back and a black crown on the adults. They are reportedly less aggressive than both the other jaegers. Relatively long central retrices of breeding adults may still be present but not for much longer. Their autumn migration through this area will take them from their Canadian arctic nesting grounds to southern South America and southern Africa.