And makes the geese sick, too
Many people enjoy watching and feeding geese and ducks at local lakes. While this may be a fun activity to do with the kids and grandkids on a lovely summer evening, unfortunately, it isn't healthy for the waterfowl or beneficial to the water and recreational quality of our city's parks.
In recent years, Canada geese have used lakeshore lawns, parks and golf courses to their advantage. With open water, few predators and abundant food sources, populations have thrived. The U.S. Fish and Wildlife Service estimates that in the early 1960s there were only 50,000 Canada geese in North America; as of 1998 that number had increased to 2 million birds in the Eastern United States alone.
In our metro area the current population is around 25,000 geese. Without controlling the population, Canada geese could number 200,000 in the Twin Cities metro area.
Geese and ducks naturally feed on aquatic plants, grasses and small crustaceans. Feeding waterfowl processed foods such as bread and other goodies can inhibit their digestion and lead to a fatal disease called crop impaction. It is also believed that these processed foods do not provide the range of nutrients the birds need for a healthy diet. Feeding waterfowl can make them dependant on humans as their food source and also leads to large concentrations of birds in a small area.
High populations of geese have negative consequences for both birds and people. Dense concentrations of birds can reduce the reproductive success of the flock and provide a situation where disease can be transferred more easily through the flock. Birds that are accustomed to obtaining food from people may also become aggressive towards humans.
Large populations of waterfowl in a small area cause soil compaction, shoreline erosion and damage to vegetation. This damage to soil and vegetation has negative impacts on the recreational and environmental quality of the area around the lake.
Waterfowl concentrations also result in a large quantity of bird droppings. Droppings contain nitrogen and phosphorus, which can cause algae growth in water. Excessive algae growth in lakes, called "blooms" or "scums," is harmful to a lake. As algae die and decay, they take away much-needed oxygen from fish, leading to fish kills and foul odors. Even the breads that people feed waterfowl contain phosphorus and have a similar effect on water quality.
Additionally, waterfowl droppings may also contain bacteria and viruses. Waterfowl are hosts of the familiar parasite that causes swimmer's itch. Feeding waterfowl, particularly around beaches and docks, may contribute to swimmer's itch, reducing the recreational quality of these public areas. If you are picnicking in an area where waterfowl congregate be sure to wash your hands thoroughly and make sure pets and children do not ingest waterfowl droppings.
Many cities are now banning feeding waterfowl in parks. So for the benefit of people, birds and the environment please don't feed the waterfowl.
Marcia Holmberg is the Environmental Projects Coordinator of the Minneapolis Park and Recreation Board. She can be reached at firstname.lastname@example.org.