Wednesday, June 24, 2009

Studly Ducks

Harlequin Duck (c) 2009 John AshleyThere are only two serious contenders for the most dazzling duck in western Montana. The male Wood Duck and male Harlequin Duck are easily our most decked-out waterfowl. But other than looking outrageously handsome, there are surprisingly few similarities between these two Montana natives.

Trying to describe the feathers on these fellows is like trying to describe a box of crayons. A male Woody wears iridescent emerald head feathers, a white polka-dotted mahogany breast, and smooth almond flanks. The male Harley sports a midnight-blue body, chestnut flanks, and white patches that vary in shape from round to crescent. The females and young of both species are mottled brown, and the female Woody wears a striped, white eye patch while the Harley hen has a round, white cheek patch.

Think of these two smallish ducks as Montana’s “common cosmopolitan” and “rare recluse.” While Woodies are pretty common in summer, Harleys are twice as rare as grizzly bears. Woodies spread out across most riparian habitats, but they prefer the slow waters of beaver ponds, creeks and oxbows. Harleys are just the opposite. They spend the nesting season on just a handful of fast-flowing Montana streams, though they’ll occasionally show up on lakes and rivers during migration.

male Wood Duck (c) 2009 John AshleySome Woodies stick it out and stay in western Montana year-round. But starting in early April, most of them migrate up from southern California and Mexico. Harleys, on the other hand, migrate east-west, and begin arriving in Montana by late-April from the Pacific coastlines of Oregon, Washington and British Columbia.

Woodies nest almost exclusively in tree cavities, with a strong preference for naturally occurring holes. They don’t do any excavating, but they will occasionally use old Pileated Woodpeckers cavities. They’re also quick to move into man-made nest boxes, when properly sized and placed. Countless Woody nests have been documented, and the nest trees might be located half a mile or more from the nearest body of water. Not so with Harleys. They are almost exclusively ground nesters, and most Harley nests are well-hidden within just a few feet of the water’s edge. They are incredibly secretive while nesting. In Montana, you can count the number of reported nests on one hand -- and still have a couple of fingers left over.

Female Woodies will often nest as yearlings, but most female Harleys won’t even attempt to nest until they are 4-5 years old. While some of the Woody hens return to nest in the same wetland where they were born, pretty much every Harley female returns to her natal stream for nesting. Woodies lay twice as many eggs (10-15) as Harleys (5-7), and some Woodies even manage to raise two broods in a summer. Harleys never attempt more than one nest per year.

Once the females start incubating eggs, the males of both species leave the nesting area and do not help with raising the young. Once apart from their mates, the adult males of both species will molt their colorful breeding feathers and wear a more female-like plumage for rest of summer. Male Harleys migrate back to the coast in early summer, before the eggs even hatch.

The eggs of both species hatch after about 28-30 days of incubation, usually in late June and July. Both species are precocial, so mom will guard her chicks but she won’t feed them. All of the downy chicks start out eating aquatic insects, but after about two weeks the young Woodies begin a gradual change-over to the mostly vegetarian diets of their parents. The Harleys will stick to a carnivorous menu.

Juveniles of both species are able to fly at about 6-8 weeks old. Their first set of real feathers -- for young males and females alike -- will look a lot like their mother’s plumage. The young Woodies will eventually wander away from mom while learning to fly. They’ll disperse in all directions before turning south for migration between mid-September and early November. Here in Montana, most of the young Harleys will get left behind on the natal streams when their moms migrate back to the coast in August or September. A month or two later, the young Harleys somehow know to migrate west to a place they’ve never been before. They will end up on the same rocky coastlines with the adults, but they won’t reunite with their parents or siblings.

Woodies are monogamous during a breeding season but can change mates from year to year. Once paired, Harleys mate for life. Harley pairs reunite on the coast and spend their winters together, and in the spring they arrive in western Montana together.

Spring is by far the best time to look for both of Montana’s most handsome duck species. The more common Woodies can be spotted in many watery locations. Here locally in the Flathead Valley, these areas include Spring Creek, Ashley Creek and McWenneger Slough. But the easiest place to see them is Woodland Park in downtown Kalispell. Just about the only way to see the rare Harleys in spring is to drive as far as you can up the Going-to-the-Sun Road in Glacier National Park, then park your car and hike or ride a bike even farther. Keep a keen eye on the swirling waters of McDonald Creek, and prepare to be dazzled.