While evolutionist John Avise sends us a “Duck O’ the Week” every Sunday, I also get regular non-duck contributions from him (birds, of course, as he’s a keen birder). Rather than hold onto them until the duck series is done, I’ll post his latest batch. John’s notes are indented.
I’ll let you identify the species, and you should be able to get them all!
I recently (June 23, 2020) visited an urban park here in Southern California and found the surface of one of its ponds to be totally covered in a thick mat of Duckweed (Lemna minuta?). I was somewhat surprised to watch birds go about their business as if there was no green blanket atop the water. They clearly “knew” that the covering was superficial because they landed, swam, dove, and fished just as if it wasn’t there. The duckweed also afforded me a fine lime-green backdrop for several artsy bird photos. Here are my pictures of several avian species on that pond: Great Egret (Ardea alba); Great Blue Heron (Ardea herodias); Double-crested Cormorant (Phalacrocorax auritus); and Mallard (Anas platyrhynchos). Nobody was visibly eating the duckweed but neither did these birds seem bothered by it at all.
You better know these last two!