- Research & Education
- Cape Cod
These past two weeks have again been punctuated by winds strong enough to shut down trips on a regular basis. The wind has been an ongoing issue this past month now…
The autumn’s jaegers have been great: Pomarine, Parasitic and Long-tailed have all been sighted over these weeks. Jaegers are notoriously difficult to differentiate between at times: Pomarines from Parasitics in particular. Most IDed jaegers have been Parasitics though these should become less abundant while Pomarines should become more abundant as autumn progresses toward the end of our season. Long-tailed Jaegers in general are far fewer and September is the best bet for spotting them. Watch, as always for the jaegers’ harassing behavior toward terns. This is ESPECIALLY important with Long-tails because they are only a little larger than our most commonly seen terns and if they are any distance away from the watcher their pale gray coloring makes them easy to miss.
On several occasions I have watched pairs of Parasitic Jaegers chasing down terns. I often wonder of the intent and reward of working as pairs. It seems more likely that a tern will disgorge its meal if harassed by the double stress of a pair. But once the food is regurgitated the chances of either individual jaeger getting that meal is lessened by the now competing other jaeger seeking the same food. On the 23rd of September several passengers got a spectacularly close look at a juvenile Pomarine Jaeger as it passed within several feet of hitting the front windshield of the Portuguese Princess II.
Certainly the most noteworthy sighting of the past two weeks was a look at a pair of Caspian Terns. They were in the Race Point Channel north of the Peaked Hill Bars on Sunday, September 20th.
They were not difficult to spot at all. With a 21 inch length, a 50 inch wingspan, and weighing just under 1.5 pounds Caspians are far larger than any other tern we would likely see here. Their tail is also a more shallowly forked than any of the adult representatives of other local terns. The only possible confusion would be Royal Terns. The Caspian’s overall appearance including the bill is stockier than the Royal Tern and the Caspian’s bill is crimson red rather than the Royal’s thinner orange bill. Both of these terns are only rarely seen here and the Royals are more likely in August to early September. This is one of only several sightings of Caspians that I’ve had in my years working locally and both those other sightings were also in the Race Point Channel. September is the month to keep your eyes out for Caspians as they migrate south for the winter.
We are now rapidly approaching the final month of our 2009 season. As part of my incorporating more pelagic birding into our Dolphin Fleet curriculum I have for the second year sent all of our weekly counts into the Cornell Lab of Ornithology’s eBird program. Cornell’s eBird program is an online checklist program collaboration begun by the Cornell Lab of Ornithology and the National Audubon Society. The program aims to maximize the use and accessibility of data collected by recreational and professional birdwatchers. That data is then made available to any interested parties, curious birdwatchers to researchers, through the eBird website. The Dolphin Fleet’s pelagic birding volunteers Liz Holbrook and Bill Lowe have been tremendously helpful in this regard. Their counting is in addition to their being available to our passengers who are interested in seabirds. As autumn progresses we are seeing more birdwatchers on the boats. Thank you to both Liz and Bill for their time and enthusiasm! And thank you to the folks at eBird as well!!!