GREASING UP

Common Merganser (Mergus merganser); female.
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Not a duck.....most ducks are plant/invertebrate feeders and their beaks do not have serrations on them like mergansers do.  The serrations are most helpful in catching and hanging on to small fish.
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This one, like most floating birds, has to water-proof her feathers regularly.  Their anal glands produce a waxy substance which needs to be rubbed onto/into feathers to maintain their "floatability."  She merely dips her beak into that gland, get a beak full of grease and spreads it around generously.
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