Last week, I wrote about seeing three common mergansers on a small pond by a busy shopping mall. Mergansers are typically wary and I was surprised to see the fowl there.

The next day, I drove past Candlewood Lake — a large man-made body of water in southwestern Connecticut — and saw literally thousands upon thousands of common mergansers. The lake was still about half frozen and many of the unfrozen portions were covered with mergansers. Some of the mergansers used the icy edges as a resting spot; others swam in the rippling water.

That setting seemed to me to be a more appropriate spot for common mergansers than the mall-area one. It got me to thinking about the merganser family and their water preferences.

We have three types of mergansers in New England: common, hooded and red-breasted. Generally speaking, they all have different water preferences.

Common mergansers are usually spotted on large, freshwater lakes and rivers. Hooded mergansers favor smaller bodies of water and may be found on fresh or brackish water. Red-breasted mergansers may be found on large bodies of fresh, brackish or salt water.

I have yet to see all three mergansers sharing a common body of water, but I have seen hooded and commons together, and hooded and red-breasted mergansers together. All three are generally wary in nature. From my own observations, I find the common to be the most wary and hooded the most brave.

The hooded merganser is the oddball among them in terms of appearance. They are small ducks and the males are handsomely adorned with pewter sides, black backs and black-and-white heads and chests. Their heads are usually fanned to display a large white patch, but can also be flatted to show just a sliver of white. Female hoodeds are similar in size to the male but are duller in color and design.

Male common and red-breasted mergansers are similar in general appearance with dark green heads, red bills, large white bodies and black backs. There are obvious differences between them, too. The common is much larger and smoother looking. Red-breasted merganser males have spiky “haircuts,” light red breasts and slightly darker sides.

The females are slightly more difficult to differentiate. Female commons are larger, brighter and have a dark rusty head with a funky haircut. Female red-breasted mergansers have a funky haircut, too, but are smaller, darker and have duller, brownish heads.

All three merganser varieties have serrated bills for holding onto fish and other wiggly prey. Those bills have earned the family the nickname sawbill.

Ducks are one of my favorite types of birds to watch and mergansers are my favorite family of fowl. So far the spring migration has been a merganser bonanza. I hope it continues.