Curious Iowa: Why are there so many geese in Cedar Rapids?

Cedar Rapids’ Canada geese population is on parade during the spring and summer months. Whether the birds are crossing roads with a gaggle of goslings in tow, chasing passersby away from nests or leaving behind droppings on pedestrian walkways, these birds are hard to miss.

Curious Iowa is a series from The Gazette that seeks to answer your questions about the state, its culture and the people who live here. One Curious Iowan wondered why there are so many Canada geese in Cedar Rapids and what can be done about them? In this edition of Curious Iowa, we get down and birdy to find the answers.

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What’s the issue with Canada geese?

Common complaints about Canada geese are that they poop everywhere, get in the way of motorists, cyclists and golfers and are territorial during nesting season.

Humane Society of the United States Director of Humane Wildlife Conflict Resolution Lynsey White said defensive behavior is commonly seen during the 28-day period that geese sit on their nests.

“Usually these geese are just flapping their wings, maybe chasing someone. I think it’s pretty rare that they actually make contact with the person and I understand that it can be scary to someone, especially if they don’t understand what’s going on,” White said. “but it’s really just a goose trying to protect their nest.”

Canada geese almost went extinct

Many people consider Canada geese a nuisance, but in the early 1900s, these birds were hunted almost to extinction. To combat this, wildlife managers created captive populations of Canada geese across the United States. These birds had clipped wings so they were not able to migrate.

“They didn’t teach their offspring how to migrate because migration is actually a learned behavior,” White said. “The descendants of these geese never learned how to migrate and they didn’t need to because they had everything they needed here.”

Today there are two kinds of Canada geese: migratory and resident. White said biologically they are identical but migratory Canada geese fly north to Canada during nesting season and return south in the fall. Like the name implies, resident geese do not migrate. Resident geese are fatter as a result.

Can a goose be taught to migrate?

“We have seen some populations of geese in the Northern U.S., like in Michigan, who have started migrating after programs of aversive conditioning.” White said.

Battling the birds or living with them

The Cedar Rapids Parks Department began tackling goose overpopulation in 1995. In 2013, the city officially banned feeding geese on public property. While feeding encourages birds to congregate and defecate in a specific area, it can also cause a nutrient deficiency called angel wing. Angel wing deforms joints in a goose’s wing causing them to jut out like angel wings instead of folding in toward a goose’s body. Geese suffering from angel wing cannot fly.

Linn County Conservation Officer Travis Graves said that larger metropolitan areas — especially cities with rivers or lakes — tend to have larger Canada geese populations.

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Over the years, the city has tried different methods of controlling the goose population, including scaring, relocating and hunting the birds.

The Cedar Rapids annual goose roundup used to gather between 400 and 500 young and adult geese and relocate them to remote areas away from the city.

As recently as 2016, adult geese were captured and slaughtered and their meat was donated to food banks. Cedar Rapids’ annual goose roundup has been discontinued.

Graves confirmed that the Iowa DNR allows metropolitan Canada geese to be hunted in specific zones in Iowa. The season begins in September, although regulations can change annually.

In 2014 Cedar Rapids parks staff and volunteers designed a remote-controlled goose chaser called FIDO. Parks Superintendent Mitch Ahrendsen said FIDO could chase geese on land and over the river to prevent gaggles from forming along the riverbank near McGrath Amphitheatre. This method was eventually discontinued due to the staff resources required to repeatedly chase geese away.

Today, the city uses an egg oiling tactic to limit the number of geese born each year.

In Iowa, a local DNR wildlife biologist must give permission for egg addling to be conducted. Then, DNR staff or licensed Nuisance Wildlife Control Operators can addle eggs, using either the egg oiling method, replacing eggs with fake goose eggs or removing eggs altogether.

In egg oiling, the eggs are coated in food grade corn oil to suffocate the embryo. Corn oil is used because it doesn’t harm the goose or affect the weatherproofing of their feathers.

“As long as that is done before the egg has been incubated for 14 days or more, then we consider that a humane form of population control or birth control because the embryo inside has not advanced enough to feel pain,” White said.

A bucket of water is used to determine how long an egg has been incubated. If the egg sinks to the bottom of the bucket of water, it is safe to add corn oil to the egg. If it floats, the egg has been incubated for more than 14 days.

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“As the embryo develops inside the egg, they eat more and more of the yolk inside,” White explained. “And as they eat the yolk, the area inside the egg is replaced with air. So the longer an egg has been incubated, the more air is inside.”

If an egg floats, the egg is returned to the nest. White said it’s best to mark where the nest is and try again next year. She said finding the nest is the most time consuming part, but once it’s found, it’s easy to guide geese off the nest using an umbrella.

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Another method of controlling the goose population is removing eggs from the nests and replacing them with fake eggs. This method can cause stress to the geese. In Iowa, this must be done by DNR staff or licensed nuisance wildlife control operators after receiving permission from a wildlife biologist.

“As required by the U.S. Fish and Wildlife Service, you either have to bury [the eggs], burn it or put it in the garbage,” White said.

What you can do to deter geese from your home

Residents who want to keep geese from feeding near their home are advised to keep patches of tall grass around water. White said geese like to be able to see all around themselves to watch for predators, so they avoid tall grass.

Another method is adding repellents to grass to deter geese from feeding. Common repellents use the same grape flavoring used in grape soda because it irritates the birds without causing harm. Geese will associate the smell of the repellent with the irritation and avoid the area.

White said that timing efforts with the goose’s biological season is the key to successfully controlling the population. Deploying these methods consistently during the day and night is also important.

“We have what I like to call a sort of magical window of time after they’ve abandoned the nest and before they lose their flight feathers,” White said. ”All Canada geese lose their flight feathers for about six weeks in the summertime and then they can’t fly.“

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Comments: bailey.cichon@thegazette.com