Recently, I have been delighted to see a small group of Common Mergansers on the river. The male’s breeding plumage is striking. He has a white body that sharply contrasts with a black back and dark green-black head. His bill and feet are red and his breast is tinged with a rosy peach. The female and immature mergansers are gray-bodied and have a rufous head with a short crest. Their chest and a patch under the chin are white. From late summer to mid-autumn, males wear a non-breeding plumage that looks very similar to female plumage. So at the moment, they all look fairly alike.
I usually see them paddling upstream and enthusiastically diving for food. They dip their heads just under the surface of the water as they swim and scan for prey. When they dive, they give a slight leap to help launch themselves underwater. When one bird dives, the others usually follow. They normally dive for less than 30 seconds, but they can stay under for up to 2 minutes! Their diet consists mostly of fish which are, of course, slippery. To help catch and hold them, they have serrated bills. Sometimes I see one surface with a fish in its bill, and if it isn’t quickly gobbled down, a chase often ensues.
They can also be seen relaxing on rocks or on a log out in the river. That said, there always seems to be one vigilantly standing guard for any predators. I also have seen them merrily floating downstream, looking around, and to all appearances, just taking it easy.
Find a spot by the river to quietly sit and listen to the water gurgling, the wind blowing through the cottonwoods, and hopefully, you will be blessed to see a flock of mergansers paddling around on the river.
Nature is an inexhaustible source of wonder. Hope to see you out there.
Common Merganser Life History, All About Birds, Cornell Lab of Ornithology. https://www.allaboutbirds.org/guide/Common_Merganser/lifehistory. Accessed 14 Sept. 2022.
Peterson, Roger Tory, et al. Peterson Field Guide to Birds of Western North America. 4th ed, Houghton Mifflin Harcourt, 2010.