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| A female-plumaged Hooded Merganser, photographed in March in Ohio. Photo by Kenn Kaufman. |
April 14: Lots of things happening today, but one observation left me scratching my head and wondering. On the north side of the auto tour route on Ottawa NWR, scanning the rather secluded Pool 9 East, I found a good variety of ducks (including the only group of Northern Pintail that I've seen in the last few days). I began to notice that the ducks included a lot of Hooded Mergansers.
During the last week I had seen only a few Hooded Mergansers, in twos and threes, around tree-lined wetlands. That made sense, because the species breeds locally in such situations, scattered through the swamps. But here on this one pond, in a careful scan, I counted 57 of the birds. That would be a large number for any time of year here, but especially at this season. And of these 57 Hoodeds, not one was an adult male; all were brown birds, essentially female-plumaged.
At this season, adult female Hooded Mergansers in Ohio are mostly sitting on eggs at scattered sites, not flocking together on ponds, so I didn't know what to make of this. After talking to Mark Shieldcastle (who knows a ton about waterfowl -- he was wetlands biologist for Ohio's Division of Wildlife for several years) and reading the Birds of North America account for the species, I'm guessing that these 57 Hoodeds may have represented a group of one-year-old, non-breeding birds. They don't breed for the first time until they're two years old, and first-year males look similar to females. (And some of these birds had a messy appearance to the head pattern, as if some black feathers had molted in among the brown, suggesting first-year males.)
Still, I don't think there's a well-known pattern of young non-breeding Hooded Mergansers flocking together like this. I have to wonder if they'll spend the summer in this area, or if they were on their way to somewhere else. I'd be interested to hear from anyone who has some insight on this question.
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