1. Mallard

The mallard is the No. 1 duck in Minnesota waterfowlers' bags because of its statewide prevalence. Its large size and the drake's florid coloring contribute to its trophy status among many waterfowlers.

• The 2019 spring breeding population of Minnesota mallards was 286,400, down from 295,400 last year.

• Minnesota mallard productivity this summer was believed to be good, thanks to persistent spring and summer rains.

• The 2018 estimated Minnesota mallard harvest was 105,149, down from 159, 718 in 2017. (However, per hunter Minnesota seasonal harvest of all ducks was fairly constant, 9.7 ducks in 2017 vs. 9.1 in 2018.)

• Mallards typically pair up as early as December, when courting parties in which multiple males display for a single female are common. Mallard pairs over winter down south before returning north together in spring.

• Female mallards commonly "home'' to northern nesting grounds, especially to sites where they previously brought off broods.

• Especially in the season's opening weeks, it's common for hen mallards to decoy readily, perhaps, according to Department of Natural Resources waterfowl specialist Steve Cordts, because they've spent so much time in summer around multiple ducks, raising broods. Conversely, many adult drake mallards fly north to Canada and elsewhere to molt, so perhaps fewer of them are in the state on the opener than later in the season.

Fun mallard facts: Contrary to common belief, drakes don't "quack;'' hens do. The drake's call is raspier. Also, mallards are the easiest ducks to count during DNR spring population surveys conducted by airplane because of their size and the drake's vivid coloring. Also, whether spooked by the airplane or technicians on the ground attempting to verify the aerial counts, mallards tend to "jump up'' and fly. Blue-wing teal, by contrast, swim away and stay hidden, making them harder to count.

2. Wood duck

Wood ducks aren't as prevalent in Minnesota as mallards in part because they're not generally a prairie nesting bird. Some do nest in the state's farmlands, but many that do nest in man-made wood duck boxes, rather than in tree cavities.

• Beaver ponds and other wooded sites that often are home to wood ducks also readily offer the nuts and berries wood ducks prefer.

• Wood ducks — the drake of which is prized for its spectacular plumage — are the second-most abundant duck in Minnesota waterfowlers' bags in part because the limit was raised from two to three in 2011. Also contributing is the state's coinciding earlier opener, which allows hunters to kill more "woodies'' before they migrate south.

• Wood ducks sometimes wait until they arrive on their wintering grounds to find mates.

• Wood ducks are "homers,'' and often return to nest in the same wood duck box or tree cavity, year after year. But their homing behavior can vary widely. Recent California research shows that some hens enter only one or perhaps a few boxes to nest, while others enter and leave scores of boxes.

• Wood duck hens may lay a dozen or so eggs. But egg "dumping'' can in some instances mean one hen will incubate as many as 40 eggs — though all might not hatch.

• Do wood ducks "decoy?'' Not very well. Often, in fact, they seem to divert over decoys, as if heading elsewhere to wooded roosts while giving hunters only passing glances. Early and late shooting hours might offer the best chances to get these fowl to set their wings over decoys.

Fun wood duck fact: Unlike most ducks, wood ducks can latch their feet onto tree branches.

3. Blue-winged teal

A fast flier and one of the smallest ducks sought by Minnesota waterfowlers, "bluewings'' might be the tastiest of all fowl. Most waterfowlers, in fact, would trade even-up a limit of mallards for a limit of teal.

• Early migrators, bluewings often depart Minnesota by mid-September, arriving as far south as Louisiana within a few days. Many continue on to Mexico's Yucatan Peninsula and beyond, where they pass the winter.

• Bluewings often fly in flocks and sometimes decoy easily. Like mallards, they can at times be called to within shotgun range, either by teal-call imitations or by mallard calls. Hunters also often see blue- wings pass over or alongside decoys before banking sharply and returning to get a closer look, or even land.

• Teal typically choose mates in winter while in the South, or while en route north in spring.

• Teal don't tend as much to return annually to the same nest site. They seem more influenced by water and habitat conditions and select nest sites accordingly. Southern and western Minnesota farmland drainage has hurt all ducks, but perhaps teal more than others. "Sheet water'' deposited in farmers' fields in spring by rain and melting snow historically has nourished teal returning to nest.

• Green-winged teal also inhabit Minnesota, and about 10 percent of hunters' teal harvest on opening weekend will be greenwings. Yet they and bluewings are different species, each (generally) favoring distinct geographical nesting areas. Also, while bluewings are early migrators, greenwings often head south much later.

Fun bluewing fact: If opening day is windy, hunters must shoot well if they hope to bag a limit of blue- wings. Flying downwind, these birds possess afterburners, their appearances and disappearances seemingly occurring simultaneously.