PIERRE — In the summer, Capitol Lake and the Missouri River provide local families with picturesque backdrops and opportunities for recreation.
In the winter, Pierre’s waterways provide a home to feathered families from the north: thousands upon thousands of Canada geese.
The Western Prairie population of Canada geese spends its summers in northern Manitoba and Saskatchewan. But when winter descends on the Canadian lakes and forests, they migrate en masse to the comparative warmth of South Dakota — and in particular, Pierre.
Spencer Vaa, the senior waterfowl biologist with the state Department of Game, Fish and Parks, said a typical year can bring hundreds of thousands of geese to the area along the Missouri River within a 50-mile radius of Pierre.
“A lot of them end up in the Pierre area, on the Missouri River reservoirs,” Vaa said. “They like to come here because they have quite a bit of stuff to eat around here — agricultural fields like corn and wheat. They generally have open water in the country around Pierre all year long.”
Vaa said the geese choose Pierre for its water supply and for food, ranging from the grass around Capitol Lake to waste grain lying in area fields. Unlike the giant Canada goose, a different breed, Vaa said the Western Prairie population is not usually an agricultural pest.
“They like to feed on food that’s really good for them, primarily corn,” said Vaa. “They eat wheat, too, and green grass — anything that’s green. In the wintertime, when it’s cold, they eat high-calorie foods, and corn fits the bill for them.”
Assistant waterfowl biologist Paul Mammenga said the geese can be annoyances when they gather on yards and golf courses.
“On a golf course or somebody’s yard, or a crop field, some people call them pests then,” Mammenga said. “Particularly when they’re eating the greens. They’re grazers who like green stuff. Their droppings in particular, golf courses don’t like.”
In contrast to the serious problems geese can cause to spring crops, what many local residents may notice most about the geese are their annoyances: loud honking and sidewalks and lawns littered with feces.
“I don’t believe they do a whole lot of agricultural damage in Pierre,” Vaa said. “The problems with them around there is the poop in the town of Pierre, and some people might not like the noise.”
In eastern South Dakota, spring soybean crops are sometimes menaced by hungry birds before they fly north.
To the annoyance of people living near waterways, Vaa said the birds often come out to feed in the morning and evening.
“They don’t sleep a whole heck of a lot,” Vaa said of the birds.
Mammenga said Canada geese tend to take short naps rather than sleep for long periods of time. As a result, many keep making noise through the night.
“Most of the time at night they go to water to roost,” Mammenga said. “Some could sleep, but a lot of them will stay awake. There’ll be a lot of vocalization there, just to watch for danger at nighttime.”
The honking noises geese make are communication, Mammenga said.
“We don’t know exactly what all those vocalizations mean, but we do know that some of those vocalizations alert everyone to danger,” he said.
When one goose puts up an alarm call, Mammenga said, other geese around it all echo the call to make sure the entire flock hears, which can produce a tremendous din.
Geese mate for life and travel in families, with a typical couple having between three and six offspring in the course of a life. Young geese travel with their parents for the first year of their life before being driven off by territorial parents at the next mating season.
The monotonous din, however, obscures the geese’s individual personalities, Mammenga said.
“Every pair tends to defend their territory differently, just like human beings act differently,” he said.
Both biologists advised against feeding geese.
The birds are able to find food on their own, Mammenga said. Geese also tend to congregate more in areas where people feed them.
“That’s when you get your problems,” said Vaa. “It’d be nice if they stayed out of town, right? If you feed them, you encourage them to come into town. They can get plenty of feed where they’re feeding out in the fields with the waste grain.”
Another risk, Mammenga said, is the vulnerability of large, high-density populations to disease, though he said the Pierre area has never had a major dieoff or epidemic.
The high volume of birds in the area is a testament to the healthy and growing population of Canada geese, according to the biologists.
“The Western Prairie population is doing well,” Vaa said. “It’s stable to increasing. There’s good numbers of these birds out there.”