I, too, had Red Admirals flying in my backyard in London in astounding numbers, commencing last Saturday, April 14 in the afternoon. At first there were only a few, perhaps half-a-dozen. By 17:30 on Monday, April 16, my best guess is that there were between 75 – 100, at any given time, in very aggressive groups, congregating around the various mature cedars and pines in the backyard of our South London. It was indeed a sight!
Observer: Suzanne Hicks