Date: 7/17/25 6:18 am From: 'PAUL ROBERTS' via Arlington Birds <arlingtonbirds...> Subject: [Arlington Birds] Six Mystery Terns at Mystic Lakes 7:30 a.m. 7/17/25
This morning, roughly around 7:30, while watching for juvenile eaglet movements I spotted six large terns flying flock-like in a wedge of 4 on one side and two trailing on the other side, flying very high, north to south, over the lower Mystic Lake. I was surprised because they were very high overhead and already well past me when I saw them against the cloud cover, flying into a 10-12 mph S wind. They were definitely terns, not any type of gull. I tried to get people, especially photographers, on to them but few actually saw the birds, and none in time to photograph them, which would have been horizontal lines on their viewfinder. I'm familiar with Common Terns, and usually we'll have several visiting the lakes regularly, though not that I've seen this year. I've seen only one. These birds were considerably larger and had slower wing movement than commons. Without getting anything other than their size, bulk, and number, the best likelihood is probably Caspian Terns. but that number and now, in mid-July? There is some reason to suspect, especially with this three-day heat wave, that they might be Royal Terns, which usually peak in mid-July, but on the Mystic Lakes? (Note, they weren't on the lakes, but flying quite high over them.) I'm wondering if anyone else in the Mystic or Charles River watersheds has seen multiple Caspian or Royal Terns the past week, and possibly the six I saw this morning, which were coming from the direction of Horn Pond... Best, Paul Paul M. Roberts Medford, MA <phawk254...>
