Grant Park Conservancy Looks for Humane Ways to Solve the Goose “Problem” in Butler Field

Canadian geese have been a problem at Grant Park’s Butler Field. Photo Credit: Monte

By Sharon Parmet

At a well-attended meeting at the Grant Park field house this past March, about 40 people gathered to hear a lecture about poop, a.k.a. “droppings,” “bombs,” “pellets,” “you know what,” or, more abstractly, “blank.”

“Like the Eskimos have dozens of words for snow, we Americans have untold number of descriptors for droppings,” said Joel Brown, PhD, a professor of biological sciences at the University of Illinois at Chicago, and the man we all came to hear speak about the Grant Park goose dropping problem which mostly affects Butler Field, where the situation is “thick,” shall we say.

Brown has previously consulted for the Grant Park Advisory Group at the invitation of Bob O’Neill, president of the Grant Park Conservancy, to help brainstorm humane ways to deal with the rabbit problem that affected the park a few years ago when portions of it were under the tight horticultural grip of hundreds of rabbits that were causing thousands of dollars worth of destruction to trees and other plantings. Brown, an expert on animal foraging behavior, especially that of the various species that live in urban areas (including rabbits, squirrels, possums, raccoons and geese), gave several recommendations based on modifying the bunnies’ behavior and which led to a a significant decrease in the Grant Park rabbit population and the destruction they caused to park flora.

The multi-pronged approach used for the rabbits included wrapping young saplings with chicken wire, making them difficult for rabbits to chew on, and reducing some of the dense wildflower patches the rabbits were using for breeding grounds and for their dens.

With one Grant Park success under his belt, Brown was back to address a new animal behavior problem. But this time, the problem was different, as one of Brown’s slides informed the audience: “Its not their gardening, its their droppings.”

Goose Biology 101

Grant Park, for the most part, is okay, goose-droppings wise. Its not until a visitor promenades onto Butler Field that their senses, not to mention their foot-wear, may become offended. Butler Field is a small area of the park used for concerts, and to show movies during the summer. The goose droppings make it nearly impossible for patrons of these events to spread out blankets and sit down, and O’Neill has received numerous complaints about the problem.

According to Brown, the reason for the staggering abundance of waste produced by geese can be blamed on their rather lame digestive systems. Whereas bunny droppings are practically sterile ash (due in part to the fact that a single poop gets digested not once, but twice…more on that later), goose poop is basically the same thing that goes in (grass) plus some digestive juices and cursory breakdown products that make it particularly mushy and gross.

What causes the difference in output quality between these two urban park inhabitants? It’s a difference in how the two animals obtain nutrients from the food they eat. Geese feed like mad, nibbling up pounds and pounds of grass and other vegetation, only to extract the minute amounts of nutrition their guts are able to absorb, passing the bulk of what they consume (which is mostly indigestible cellulose). A single goose turns 1,500 pounds of grass into 750 pounds of droppings. A rabbit on the other hand, a much more efficient digester (but with the terrible price of having to eat its own poop, or “night pellets” in order to absorb enough water) takes its 1,500 pounds of grass, etc. and transforms it into just 150 pounds of droppings.

Goose Psychology 101

Solving the goose dropping problem starts with gaining an understanding of how geese behave, what makes them tick, and most importantly, how and why they congregate in large flocks.

Brown started with a general overview of the goose life cycle: Geese breed between March and May and form pair bonds that last for the breeding season, and sometimes for life. The female lays five to six eggs and incubates them for about 28 days. After hatching, the geese fledge in 45 to 70 days, and take two years before reaching sexual maturity. The male goose undergoes a molt right after the eggs are laid. During his molt, he can’t fly, but that’s okay, since his duty is to protect the nesting mother goose. The male goose takes this chore seriously, running after any threat that comes too close to the nest and hissing like mad. The female undergoes her molt while incubating the eggs, when she doesn’t really fly anyway.

After fledging, young and adult geese spend several months bulking up on grass. Brown says that come the colder months, migration is optional for geese who have been feeding plentifully on the grasses in city parks. “If food is around, geese will tend to stay until there’s pressure on them to leave to seek other food sources,” says Brown. Geese can migrate later in the season if food sources become depleted. Geese tend to visit multiple feeding sites, staying until the amount of energy they must expend to extract more nutrition becomes prohibitive (like when the goose really has to look for those last few blades of grass on a heavily grazed field). Then they move on en masse.

But geese don’t look for just any patch of grass – they look for open, mowed fields, clear of obstructions like tree stands, gardens and other structures that can break up the field. This setup provides the best landscape for these relatively heavy birds to take flight. A goose needs about a dozen clear feet in order to run and gain liftoff. However, geese prefer to escape danger by waddling into water, an evasive maneuver that requires much less energy than taking flight. For this reason, the most attractive goose landscape is an open, mowed field with a slight decline leading to a body of water. Geese also like open spaces because they provide clear sight-lines and they can see danger coming from a long way off.

So, its no surprise they like the open space of Butler Field. Knowing how geese operate lends valuable insight to researchers and park planners regarding ways to discourage geese from visiting certain areas. Brown gave several suggestions on how to make Butler Field less attractive to geese. Most involved reducing the open space of the field by either planting trees or hedgerows, or by stringing streamers up between the light posts that circle the field, making it less attractive for them to land and take off from. Installing small architectural elements, perhaps sculptures or arches, was another suggestion.

O’Neill says that the Grant Park Conservancy is closely examining several of these options to help reduce the goose population in Grant Park, including the streamers, planting more trees and adding mini-gardens. “We want to try to develop ways to balance our human and wild populations in the city,” says O’Neill. “If you think about it, it’s a good problem to have – the Canada goose was almost extinct in the 1960s due to hunting and habitat destruction. Now that they’ve rebounded, we owe it to them to come up with humane ways to make specific urban landscapes used heavily by city people a little bit less attractive to them.”