Date: 8/19/26 8:33 am From: 'PAUL ROBERTS' via Arlington Birds <arlingtonbirds...> Subject: [Arlington Birds] Tyrants Thought To Leave Arlington (Mystic Lakes)
Since May, Eastern Kingbirds have been reasserting their aerial dominance of the Mystic Lakes, and their purported ownership of those bodies of water. Historically, Eastern Kingbirds have nested on either side of the dam, most frequently in the cottonwood known as THE TREE, or THE EAGLE TREE, where most of the year a pair of territorial Bald Eagles frequently perch to oversee the nesting and feeding territories they claim and maintain there. The tree offers great views of both lakes (including the Upper Forebay). It also provides a member of the territorial pair the opportunity to display its white head and tail to any other eagles in the vicinity attracted by apparently great sources of fish and eels and the possibility of nesting in what is in some respects a "gated community." Thus, during much of the year, one might see an adult eagle perched there, until early May when the real owners, a pair of Eastern Kingbirds, returns to nest in THE EAGLE TREE, which in their eyes should be THE EASTERN KINGBIRD TREE. They will harass most any raptor, but especially big, lumbering ones that foolishly decide to perch in it, especially on top of it. Kingbirds will mercilessly harass a sitting eagle, rocking back and forth in the air, literally hitting the head of the eagle, causing it to duck, squirm, and often scream in frustration. Kingbirds are well known to land on the backs and necks of flying raptors, especially aircraft carriers like the Bald Eagle, standing on the neck of the bird pulling out neck feathers one by one, painfully. Kingbirds scientific name is Tyrannus tyrannus, meaning "tyrant, despot or king." You remember playing "king of the hill." That is the essence of a kingbird's life. They are largely insectivores, so do not compete with the eagles or Osprey for food. They just want to show who's boss. (Remind you of anyone nationally?) This year the kingbirds nested in the eastern cove, near the "Osprey Tree," the large bare branches offering a nice perch east of the dam, often frequented by Ospreys and occasionally eagles, herons, and other birds. When Kingbirds see an eagle perched there, it seems genetically required for them to drive the bastards out. They are so effective in driving off the Bald Eagles that after a week or two of hell, the eagles virtually give up trying to perch in some of their most favored spots. However, the past several days KZ has perched in the holy of holies and not been harassed. There are at least two kingbirds still present, but I have the distinct impression, nothing more, that the adults have already dispersed and will soon be migrating to South America and Amazonia for the winter, but have left two kids in charge of their property for several weeks. They perch on the Osprey tree, and often fly watch across the dam. Often they head out over the water maybe 50 yards or so, hovering frantically. They are likely insecting, but also showing the flag. Several weeks ago KZ landed on the Medford Boat Club Dock and was soon harassed by a kingbird. He took off with the kingbird on his back beneath our viewing level, proudly displaying the bright red crown spot that they display only when really agitated. The flycatcher was photographed pulling out feathers beneath us, riding the bucking eagle over the dam, past the boat house. I haven't seen KZ on the dock since or on any of his favorite perches until this week. Several weeks ago Stripe perched on her favorite spot in THE TREE, but within minutes thought she had died and gone to hell. She fled and has not returned to that perch for weeks. What I think are the juvenile kingbirds, fly sentry over the dam, between the Osprey and Eagle tree. Last year, when there were kids with Fae, they "strongly discouraged" juvenile eagles from perching on what the kids knew to be some of Mom and Dad's favorite perches. I saw kingbirds harass a juvenile for almost a third of a mile back to the nest, just to show the kids their place. Speaking of Stripe, she and KZ are still a pair, but rarely together. It currently appears a marriage of "state," at least in his eyes. He has shown minimal interest in her, spends very limited time with her, and l know of only one incident where he left fish (remains) for her. She has been more proactive in the relationship than I've seen him, but this is the down season. The gonads are so small you couldn't find them with a map. When cold fronts start dominating the weather and you're hearing large aircraft taking off over Medford and Arlington, we'll see if the relationship returns to a low boil. Or heating up to a "hard ball stage," for those familiar with making confections. I've seen modest number of nesting eagle pairs over the past twenty years, but I've never seen a male so enthusiastic about his mate as KZ was when he first found Stripe. Was it merely an infatuation, or the basis for young to come? We shall see. Whatever, I expect the juvenile kingbirds will depart within a week or two and the rhythm on the lakes will become more familiar. One note. Since April I have been working through my photos and notes, and observations and photos of several others, seeking to understand what exactly happened with Fae's illness and death, and KZ "selecting" a successor. It has taken much more effort and time than I ever considered. Going through roughly 20-30,000 photos individually, taking new notes from those photos and building up a binder of notes completely separate from thousands of my audio field notes. I was getting close to a conclusion when I lost use of critical applications until I was able to buy and receive a new computer. That was over 6 weeks ago. ("Your computer is scheduled to ship from China in about 45 days.....") I have to go through all my notes again before I start writing. What I can say is that I have been learning more than I ever imagined about eagles and their behavior. About individual eagles and eagles in general. What I observed with MK, KZ and Z74 six years ago was truly unusual. After six years and much more reading and research, I've found no indication that the behavior I observed and reported on then was common or normal, especially at that stage of the breeding season. I have the feeling that what I've seen and hope to report on from this past March and April, is the opposite. Something that is much more common and informative than many "casual" (and I use that term lightly) eagle observers might believe. Whatever, I am certainly learning a lot, and can hopefully help those who are interested learn more. Best, Paul Paul M. Roberts Medford, MA <phawk254...>
