Waterfowl at South Platte Park

Cooleylakevertical065aEach spring, college students head to Florida or other southern climes to soak in the sun and water. Birds do, too, and the luckiest will head to South Platte Park, where a kingdom of waterfowl cruises placidly on a wide lake in the middle of suburbia.

The 1965 flood that created a bird haven at Barr Lake in Brighton also flooded homes in Littleton. In response, engineers channeled the river, doing away with its original riparian environment. It’s worthwhile to take a look at both lakes, because the channeling now invites ducks and geese rather than the variety of smaller songbirds birds found at Barr Lake. And the warmer waters that flow from dammed water invites ducks to stay later and arrive earlier. It’s a lesson in both engineered and natural riparian environments.

“Ducks are great to start with if you are interested in birds,” a volunteer guide says as we set off for a hike, “They’re large and don’t spook easily.” Ducks and geese also are visually striking, which makes them easy to point out to the birding novice. Black and white coats with a dash of iridescent green or vivid red always provoke an outcry from the group. Today we’ll see gadwalls, American widgeons, a great blue heron, belted kingfishers, buffleheads, pied-billed grebes, a northern pintail, common merganser as well as the usual Canada geese and mallards. While songbirds may be recognized by their sounds, these waterfowl, once caught in the scope, will show off their plumage.

Cooleylakepeople057aOwned by the city of Littleton, South Platte Park’s Cooley Lake is 230 acres of water. Once a gravel pit in the 1950s, the 1965 flood not only changed the terrain, but forced citizens to consider how best to stem flooding and preserve some natural beauty. Years ago the river flooded periodically, which fostered a lush cottonwood forest and thousands of songbirds like warblers, nuthatches, catbirds and sparrows. “Today we have a totally different system,” a resource specialist says, “we have a declining cottonwood forest and a loss of riparian birds. The winners, however, have been the waterfowl. They have joined the raptors like eagles and hawks.”

Altogether, the park meanders for 2 and a half miles, an overall size of 50 square miles with 150,000 human residents and 230 sighted species of birds. Bordered by a few horse farms and housing developments, a hike is scheduled each month. The path is opened only on that one day to minimize the impact on such a fragile environment but allow the curious to wander close to the lake.

Our guide takes us out with a scope slung over one shoulder and a bird guidebook on hand. She helped with the bird census, joined the nest box program, contributed to the Colorado breeding bird atlas and now guides a group of 20 down a path toward the lake. A coyote slinks behind us, heading for cover in tall grasses.

Cooleylakeweeds43a“I got into birding by accident,” she says, “I think birds are fascinating animals. When you think of all the things that go into a creature that flies–they don’t have arms, most have hollow bones, just the right musculature. They can’t have teeth–those are too heavy. Consider their feather maintenance, feeding their family and slight weight. Even a large eagle doesn’t weigh much if you put them on scales. Yet, birds are everywhere. You can take a walk in your neighborhood and see lots of birds. That’s not true with other wild creatures.”

A devastating disease can make even the most ordinary bird more welcomed. We spy a magpie and her face lights up. “We lost so many of them last summer. They were particularly affected by the West Nile Virus,” she says. Some scientists believe at least 80 percent of the magpie population may have died. To see them rebound is testimony to their grit and endurance. But they are not the main draw today.

We are headed to the hundreds of bobbing birds on the lake. One grand attraction of the lake is a warmer temperature than a natural lake. Because water flows slowly from Chatfield Dam, the temperature is warmer than an icy river filling a body of water. That prevents the lake from freezing solidly and waterfowl flock to the 38-degree water, often staying year round when they might have migrated in previous years.

Historically there would have been more freezing. But it’s not overpopulated yet. Since predators like the coyote keep an eye out for a fat duck or goose, the birds rarely stray onto the grassy knolls. Canada geese must eat grasses nearly constantly and would rather head to a golf course than tangle with a predator. Also, the summer grasses at the water’s edge are not the choice of menu for the geese. That’s fortunate because overpopulation leads to disease.

Most ducks feed on grasses; that’s why they’re upended with tails in the air as they snatch a tasty weed. These birds will eat their fill, become fat and sleek as a way to store energy for a long migration. Many will head to South or North Dakota, Montana or Canada as the weather heats up.

As we search for a common goldeneye or gadwall, it’s easy to see why ducks have been a favorite meal in nearly every cuisine. With their plump bodies and slow waddle, they’re hardly the darting miniatures that make up many birds. Even so, mallards are a successful species, judging by their numbers. That may be because they are generalists–not linked to a specific food or terrain. Generalists often can adjust to environmental changes more easily than other kinds of species.

That explains why ducks will follow people for a handful of breadcrumbs, despite the fact that bread won’t contribute to waterfowl health. In the duck cafeteria, mallards eat grubs and a wide variety of plants, all in the quest to put on weight. To fly long distances, they line up in a tight V-formation to take advantage of aerodynamics. A hearty population is linked to water and abundant greenery at the bottom of ponds. These birds increased in the 1990s when we had very wet years. There has been a drop since then, attributed to the drought of the last few years.

Bird watchers note striking differences each year. One year the common goldeneye ducks arrived in mass. The next year, few showed up. You can be assured of about 40 species each year, but exactly which species is harder to guess. Most birders say they notice what comes in rather than what is missing. And that’s what keeps longtime birders returning each month.

Cooleylakehorizontal053aIn the meantime, someone spots a red-tail hawk, circling above a tree on the other side of the lake. A female hawk sits in a nest, hawk profile prominent through the lens of the scope. “She’s taken over the bald eagles’ nest,” an experienced birder suggests. “They nest early. They could have babies by now.” We pack up the scope and head back to the nature center after one last look at the grebe, which dives again and again for tiny fish. The grebes look like little swans, a birder observes. A belted kingfisher swoops by and our guide smiles: “That’s our mascot,” she says, about a small black bird with a comical topknot.

By May, as a few songbirds move in, some quacks will be replaced by trills. The shore birds will be scurrying about as raptors soar above. Only a few of the water birds will be bobbing on the lake, the majority will have moved on. Next year will bring another group with a shift in population, and perhaps the common goldeneyes will return.

South Platt Park, Littleton Parks and Open Space

Directions: From south Denver (E-470 and US-85), proceed north on US-85 (Santa Fe Drive) for 1 mile. Turn west at Mineral Ave and take an immediate right at South Platt River Parkway. The park’s Carson Nature Center is one block up on West Carson Drive, at 39.5831N, 105.0287W

Features: The park features a 2-mile nature walk between Cooley Lake and the South Platt River. Dogs permitted, on leash. But on guided tours, best to leave the dogs at home.

More Info: Carson Nature Center, 3000 West Carson Drive, Littleton, CO 80120, 303-730-1022,http://www.littletongov.org/parks/ssptimeline.asp.