CEDAR RAPIDS — The latest strategy in the perennial battle with geese in Cedar Rapids is corn oil, and it’s being rolled out for the first time this spring.
Brent Neighbor, a Cedar Rapids parks maintenance supervisor, has been out three times so far this year, with support from the Iowa Department of Natural Resources, to locate nesting sites and coat recently laid goose eggs with corn oil. This stifles the flow of oxygen to the embryo and sterilizes the egg, which prevents a new gosling from hatching.
“This has been recommended by the Iowa DNR,” Neighbor said. “It’s been a progression working with DNR and management strategies. This has been deemed to be the next step in progression since other strategies did not work as effectively as we’d hoped.”
Each year, officials take steps to reduce the number of geese, which leave behind droppings, hiss at passers-by when goslings are present, and are viewed by some as a nuisance.
Oiling is seen as the “most humanely recognized method of population control for Canada geese,” according to city officials, and more effective than past approaches, such as laser beams, robotic dogs, roundups, relocation, slaughter and outlawing feeding them.
City officials had identified oiling last year, but it was too late in the season to implement. The proper window is March 15 to April 15, and this year Neighbor went out on March 15, around April 1, and then on April 15.
The effort resulted in oiling 1,000 eggs from 200 different nests mostly located on islands in the Cedar River. Some of the eggs already have been collected, and early results are positive, officials said.
“We have been thrilled with the early results of egg oiling and the potential it has to significantly impact the goose population in Cedar Rapids,” Parks Superintendent Daniel Gibbins said in a news release.
The method involves addling, in which the eggs are quickly tested for development, coating the eggs in oil if they are still in an embryonic stage, and returning the egg to the nest for two to four weeks after which the eggs are removed. Because the eggs remain present in the nest, the goose does not lay new eggs and by the time the eggs are removed, it is too late in the season to lay eggs, Neighbor said.
Reducing the number of goslings born is expected to have benefits for years to come as fewer and fewer birds, theoretically, are “imprinted” to Cedar Rapids, he said.
“This reduces the population born in Cedar Rapids,” Neighbor said. “Once Cedar Rapids is imprinted as the place of birth, that’s the place they reside. Even if they leave all winter long, they come back. That’s the problem we had with relocation.”
The most recent estimate for geese in Cedar Rapids is about 2,000, but the count is dated, noted Gail Loskill, a spokeswoman for the parks and recreation department. City officials estimate oiling will reduce the goose population by up to 1,000.
The Iowa DNR conducted an effective egg oiling operation in Cedar Rapids in 2004 and 2005, oiling 1,500 eggs, but that effort was discontinued.
Neighbor is licensed to oil the eggs, which is required, and will be working with DNR wildlife depredation biologists for the next two years as part of his training. The oiling method will be the ongoing goose-control strategy and the effect likely will be more noticeable as time goes on, he said.
Cedar Rapids legalized urban goose hunting for permitted hunters south of Highway 30 and west of Interstate 380. That option remains on the table. Iowa DNR regulates licensing and the waterfowl hunting season, which runs from September to January.
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