Goose Feces: How much fecal material is left by the urban geese in Vilas Park? What microbes are present in the feces? What are the potential effects of their feces on the soils and on water quality?

Density of Goose Feces in Vilas Park

Composting of Goose Manure

Filtration of Goose Feces
The problem of goose feces build-up in public areas is fast becoming a major problem, both for aesthetic and health reasons.

The Canadian Goose has no real predator in most areas epically in metropolitan areas where they tend to settle in public parks, wildlife refuges and peoples homes.

On average a goose will produce around 5 pounds of feces a day. With this much waste being produce a day a waste build-up quickly becomes a problem in public areas.

This is exactly the case at Lake Wingra in Madison, WI. Looking at the problem we decide to focus our attention on what was the potential harm to the groundwater, rivers, and lakes where these

Experiment
In order to test the effects of goose feces we collected several fresh goose droppings from the Lake Wingra area. We combined the feces with deionized water to create a solution. This solution was then run through a 2 micron filter to separate the water from the bacteria. The bacteria samples were then incubated and bacteria colonies counted.

The results were not surprisingly much bacteria, several hundred colonies, was grown from only a few drops of solution. To further examine the feces we tested the solution for e. coli bacteria, the solution did test positive for e. coli.

The next part of our experiment was to see what types of soil might filter bacteria best to hopefully provide some data on how to better control bacteria filtration. To do this we once again create a feces solution, we now poured 1.5L of solution into each test tube, which then filtered into a sealed collection beaker. The collected solution was then run through the same 2 micron filter and incubated.

Our results were surprising!

Equipment Used
In order to test the different filtration of the feces solution we had to make our own testing equipment. By taking 4" PVC piping that was 3' long we capped one end. Fiberglass screening was now cut and placed at the bottom of each tube to help keep unwanted sediments out of the collection beakers. Drilling a .5" hole in the center of the cap we attached a 2' long piece of plastic tubing. We now build a rack that supported the "test tubes" 1.5' above the ground. Now the plastic tubing was run into a sealed beaker.

Each tube was filled with 6" of washed pea gravel and then 4" of sand in order to keep unwanted sediments from filtering through into the beakers. Next each tube was packed with 24" of different soil types. They contained soil from Lake Wingra, commercial potting soil, and a mixture of sand and gravel.

The tubes were now ready to have the solution poured into them

Results
Results of Soil Filtration
Control: 920 colonies
Potting Soil: 2070 colonies
Vilas Park Soil: 5000 colonies
Sand and Gravel Mix: 250 colonies

Our results showed that the bacteria levels rose dramatically when the feces solution passed through both the potting soil and Lake Wingra soil. But decreased when filltered through the sand gravel mixture.

One possible reason for this is the bacteria are gaining nutrients as they pass through the soils. The increased nutrient levels allow them to greatly reproduce. The large amount of bacteria in the soil from Lake Wingra might be due to bacteria already present as a result of previous goose droppings.

The sand and gravel mixture lacks any nutrients that might help the bacteria grow in the other samples.
 

Distribution of North American Geese