Words On Birds 09-12-25

 

     The swallow show on Plum Island is winding down, though we have still seen thousands in the last few days. It likely peaked around the end of August when Matt Sabourin of Newton took a more scientific approach to trying to count the number of swallows present. 

 

     On August 30, Matt took pictures of the flock of swallows across the sky, as he explains, “attempting to have little to no overlap in them, in rapid succession, ending up with 28 photos altogether, over 24 seconds…I tried to pan in a way that went against the movement of the cloud to avoid getting pictures of the same birds traveling through the various frames. Obviously this will not be 100% successful, and the movement was more of a boiling mass as opposed to a steadily moving flock going in one direction.”

 

     Matt then took those photos and “had ChatGPT run a SimpleBlobDetector” analysis. Now I have no idea what that is. It doesn’t sound “simple” to me.  It isn’t even a language that I understand. But Matt explains his approach carefully to estimate the total number of swallows that night to be 188,971! Not 50,000 or 100,000 – estimates that I have seen from reports of highly skilled birders. But closer to 200,000 birds in the sky at one time!

 

     Those of you who are interested in Matt’s methodology to come up with his estimate of 188,971 can access his eBird report here: https://ebird.org/checklist/S270492306  It is easy to read, and follow, and I found it fascinating. Nice job, Matt!

 

     As the swallows depart and the we get deeper into the fall migration, it is that “anything can happen” time of year for birders. It is the time when many “vagrants” show up, birds that do not usually come to New England. Some may be first year birds that wander in the wrong direction from their home. Some may be “wired” to migrate in the wrong direction. Others are driven here by winds and storms, such a hurricane. Thus, birds that “shouldn’t be here” appear.

 

     An example is the magnificent frigatebird that appeared on Cape Cod this past week. Reports came from Hyannis and then Chatham, with Mary Keleher photographing it on a mast at Chatham Light. Sibley describes the frigatebird as “sinister-looking, angular, and black, with long, sharply pointed wings, and long forked tail usually held closed. Extremely buoyant in flight, soars and glides effortlessly for hours.” 

 

     The frigatebird is usually found in the warm waters of the Caribbean and can be seen in south Florida and Texas. It probably found its way to the Cape on the winds of recent hurricanes and storms moving north in the Atlantic. 

 

     The other “vagrant” bird that appeared closer to home this week is a western kingbird. This bird was found on Plum Island by Tim Swain this past Tuesday and, as of this writing, has stayed for at least 3 days. Our black and white eastern kingbird, a number of which nest on Plum Island, have mostly migrated south already. The western kingbird has a gray head and chest, a bright yellow belly, and a black tail with white outer tail feathers. This handsome bird has been feeding on insects around the “Pines Field”, the open area just before the entrance road to the Pines Trail parking lot. Many have seen this rare bird from that parking lot.

 

     The kingbirds are members of the flycatcher family and other vagrant flycatchers often find their way here in autumn. Most spectacular are the scissor-tailed and fork-tailed flycatchers, and the brilliant red vermillion flycatcher that have all found their way to Plum Island. Couch’s kingbird once appeared on the island and a tropical kingbird is possible. These two birds look similar to the western kingbird.

 

     Less rare is the tricolored heron that has been seen in Bill Forward Pool and the North Pool for the past month or so. Once called the Louisiana heron, one or two of these show up in the area every year, though they are far more common in the south. This smaller bluish-gray heron with a white belly often puts on a show, running after fish with its wings extended and can be seen from the Hellcat dike.

 

     So enjoy this cooler fall weather, and keep an eye out for the different birds that might pay us a visit this season!