What Is That … Merganser?

Waddells

As a change of pace, this article focuses on a diving duck rather than following a theme about half a dozen or so beasties.  We are taking this different approach because we have had such fun watching a common female merganser and her brood this year, and we would like to tell you a dramatic life story about this family.

Let us start, though, with a little background.  We first noticed mergansers here on White Lake in 2012.  We did not know what species they were and it took some time to identify them.  It can be tricky for novice birders to discern differences between species.  Eventually, however, we learned that we have two species of merganser here, the hooded merganser and the common merganser.  When in full breeding plumage, the male hooded merganser with its showy white crest is one of the most handsome birds on the lake. And the female with her greyish brown crest is beautiful too.

But this story is primarily about common mergansers which are a little larger than their hooded cousins, and almost as beautiful.  The male common merganser has a dark, dark (almost black) green head; the green ends on the neck where the solid white of the breast and sides takes over.  The female’s chestnut head is interrupted by a white chin patch, before also ending on the neck to contrast with her white breast and grey back.  The following photograph is of the male common merganser.

This year, we first saw the common merganser female with her brood of chicks in mid-June.  Along paddled mother with eight of the cutest small ones close behind.  Later in June, we noticed the family hunting small fish close to our shoreline.  By then, the juveniles were braver and were scattered about in the water practicing swimming and diving.

Eventually, the mother climbed up onto our old wooden dock.  Babies followed and it looked as though they were settling in for the evening when suddenly mother perked up and looked into the water.  What did she see … a potential meal?  Well, a meal yes but only if you turned the table and put the juvenile mergansers on the menu.  We too saw what had caught the mother’s attention … the head of a snapping turtle as it walked underwater towards the old dock.  (Remember, snapping turtles mostly walk on the lake bottom feeding on vegetation, aquatic insects, fish, crustaceans and baby birds floating on the surface.)   The mother kept a close eye on that old snapper for half an hour or more.  The snapper finally seemed to give up, and eventually, mother merganser returned to the water with all eight babies quickly and closely following her, away from where the snapping turtle was last seen.  We wondered if the mother merganser’s decision was a wise one.  Who are we to say, though?

Several days later mother merganser and six juveniles returned to our shore to swim and fish as they had on that dramatic evening.  After feeding, they spent some time lazing on the beach, before leaving with a couple of tired ones riding on the mother’s back.  Life around Three Mile Bay carries on.

Interestingly, friends with whom we have shared this story invariably cheer on the common merganser and her babies, grumbling about that old snapper.  Cuteness prevails. But we think it is important to bear in mind that snapping turtles need to eat too. Also, they are defined as a species of special concern by Ontario; common mergansers are not.

For more information about mergansers and other waterfowl, we like Chris Earley’s very readable Waterfowl of Eastern North America.  Many of his books are available at the public library.  Chris is an interpretive biologist at the University of Guelph.