The Great Wild Goose Chase

I receive questions every year concerning how Wellfield staff control our population of Branta canadensis, or Canada goose, so I thought I would share what we have tried and are trying at Wellfield.

True to any good integrated pest management (IPM) program, Wellfield first determines if a particular organism is truly a concern or not. Just because particular insects (or otherwise) happen to make a home in your little love nest does not mean the nuclear option need be invoked. Canada geese, in this context, leave behind little green gifts on paved and unpaved surfaces, detracting from the guest experience. Due to overgrazing, these waterfowl mowers keep the turf they eat so closely cropped, broadleaf weeds invade. Thankfully, they have caused little other ornamental plant damage here. All these points add up to justification enough to employ humane control measures.

If you are inclined to complain (like I am) about this particular species, I am here to inform you that WE, not the geese, are the problem. What?! Mother Earth was designed as giant self-regulation system with lots of feedback loops. When there is a problem in the garden, we are being given feedback something is not working, right? In garden-systems, as in ecosystem, problems emerge when there is an excess or a scarcity of resources. Broadleaf weeds explode in the lawn due a lack of competition from weakened turf grass, for example. Normally, nature relies upon a lovely system of checks and balances, removing problems, but that’s not necessarily so in the typical American garden. The more modifications humans make in their garden-systems, the more reliant upon human intervention the system becomes. We create perfect goose habitat in excess, thus there is an excess of geese to the point of literal pollution with few, if any, “natural” checks. We then spend time, money and energy dealing with a problem which natural systems are better equipped to control. We provide acres of turf easily accessed via surface water by the millions and boom: “honk, honk.”

Another principle of IPM is to control the target species by observing and interacting with the species, looking for patterns from which to design a detailed plan. We know several things concerning goose biology. One, they mate for life, squaring off with other mating pairs from February to late March in this part of Indiana. Beginning the first couple of weeks of April, each pair settles on a chosen site and lay between four to seven eggs on average. Incubation lasts between twenty-four to twenty-eight days. We know Canada geese molt, or change out their wardrobe, every June and thus cannot fly during that period.  We also know goslings return year after year to the location of first flight.

Armed with such knowledge, we use several methods at different times in the goose calendar of events to manage the locals. Many different methods and products are available and will not be covered here. Wellfield has tried a number of different methods that did not work long-term. Restricting water access through creating shoreline barriers, such as trip wires or wide plantings of tall perennials (ie,-shrubs and grasses) have not worked in this context. The research suggests between ten to thirty-foot plantings to inhibit geese from swimming ashore with blue grass munchies. Geese, I have found, simply take to the skies and fly over the man-made or natural barriers. The planting design may need improving.

Wellfield’s current approach involves several action steps. First, we obtain proper Department of Natural Resources (DNR) permitting and registration with the US Fish and Wildlife. Second, nests without eggs are removed in the spring. Third, staff place eggs in a bucket of corn oil, coating the entire surface of the egg, blocking pores in the shell surface, inhibiting development of the embryo while the parents continue to sit upon the nest, caring for the egg. The key is to not destroy the eggs, which will induce the pair to produce more eggs. Fourth, we restrict the food supply by reducing overall square footage of turf and employing commercially available repellents on trouble areas where turf already struggles due to high traffic and overgrazing. Lastly, geese are rounded up during the June molt (when they cannot fly), legally transported and released on public land. The parents may return the following year, but any goslings will not, thus keeping the population from growing exponentially. Employing multiple methods has kept the geese population manageable, doing what nature would normally do for us.

Josh Steffen, Horticulture Manager, Wellfield Botanic Gardens