Swans worldwide are a small family of seven species. Minnesota sees three of those each year (probably).

We see resident trumpeter swans, migrating tundra swans and invasive mute swans. (The migrating tundra swans will be arriving shortly.)

Trumpeter swans are here because of an extraordinarily successful reintroduction program. Native to the state, these birds were extirpated throughout the Lower 48 states during settlement days, hunted for food and sport, habitat put to the plow.

There is now a growing population in Minnesota alone of nearly 30,000 birds scattered between our borders with Canada and Iowa. The Twin Cities area has dozens of nesting pairs.

Reintroduction was started and managed by the DNR in the early 1980s. The Three Rivers Park District also had a program.

We see the second species, tundra swans, in migration, spring and fall. They nest in northwestern Canada and winter in Chesapeake Bay along the Atlantic. Draw that flight path and you cross Minnesota.

With very good luck you can see a long V of tundra swans overhead, alerted to their presence by the faint whoo whooing calls drifting down from the flock. I think those few rare moments if you catch them are the best Minnesota offers in fall birding.

The third swan here is the mute, a nonnative species kept by some waterfowl fanciers, and subject to occasional escape. When possible, mutes are recaptured by the Department of Natural Resources. Mutes are European birds introduced in North America to fancy-up waterfowl collections. They are environmentally destructive.

The mute swan is easy to identify. It's the big white bird being chased by a uniformed man with a net. Seriously, the bird has an orange bill as an adult, grayish-pink as a juvenile, and black legs. Escapees are rare.

There also was a one-off black swan seen on Lake Harriet for several winter days a few years ago. Another collected European species, it too was a fugitive.

Trumpeter swans are larger than tundra swans, not much of a clue if the birds are not together. Trumpeters have straight black bills. Juveniles are dark gray. Trumpeter swans almost always are seen alone, in pairs, or in small family groups; that might be your best clue.

Trumpeter swans are well named. Their low-pitched calls can be loud.

There is a Mississippi River location downstream from the Monticello nuclear power plant where warm water discharged from the plant attracts overwintering waterfowl. Most of them are trumpeter swans, hundreds of them, not flocks, just birds sharing a warmup.

Tundra swans are likely to be seen in large groups, flocks or flock remnants; they migrate in flocks. This swan has a black bill as an adult, grayish head and neck as a juvenile.

Many tundra flocks take a migration break when they reach the Mississippi River's Weaver Bottoms river marshes in Winona County. They also can be seen at Alma, Wis.

According to the Minnesota DNR the best time to view tundra swans is mid-October through mid-November.

The DNR website offers these directions to two prime viewing locations for tundra swans — the Watchable Wildlife Observation Platform at Rieck's Lake Park near Alma, and roadside observation on the Minnesota side from Hwy. 61 near Weaver.

Alma is 85 miles south of St. Paul. Take Hwy. 61 to either Red Wing or Wabasha and cross the Mississippi River. Follow Wisconsin Hwy. 35 south to Nelson. From Nelson, continue south on 35 for about 6 miles. Rieck's Lake Park will be on the east side of the highway, just before crossing a bridge.

The Weaver Bottoms marshes lie approximately 120 miles south of the Twin Cities on Hwy. 61. For a good overview of the Weaver Bottoms area, drive southeast on Hwy 61, 1.75 miles past the Hwy. 74 junction. Take the spur road a short distance to the top of the hill.

For information about swan-watching at Rieck's Park in Wisconsin visit wingsoveralma.org.

To see trumpeter swans by the dozens visit Crex Meadows wildlife area in Grantsburg, Wis., where they nest. Best viewing is along Phantom Lake Road. Water levels are very low right now. Viewing likely will be better in the spring.

Lifelong birder Jim Williams can be reached at woodduck38@gmail.com.