|Mother Goose…Queen of Fertility.|
Goose Repellents: How Geese and Fertilizer are Alike
by Michael A. Champ
|Part One |
Everybody loves Canada geese (Branta canadensis). They are the role models of the bird world, beautiful, intelligent, smart, mate for life, excellent parents, survive harsh environmental conditions, battle Mother Nature, migrate and navigate thousands of miles in all kinds of weather.
But geese are similar to fertilizer, as in the old farm saying: “A little fertilizer is good but more is not better”.
The pilot, “Sully” Sullenberger conducted a heroic full emergency landing on the Hudson River in freezing water, without any fatalities among the 155 people aboard. This was the first time in 45 years that a major aircraft has crash landed onto water without fatalities.
The impact of geese is well documented. The most recent major example is the crash into the Hudson River of US Airways Flight 1549, Jan 15, 2009, after a collision with a large flock of geese as the plane reached 3,200 feet, three minutes after taking off from LaGuardia Airport.
As urban sprawl invaded the country, conversion of farm land into suburban areas included many ponds. Combining practices of mowing grass for greenbelts around ponds and the decline in natural predators led to a significant increase in resident geese populations. Over the last 30 years in the northern and mid Atlantic states east of the Mississippi, Canada geese have become a pondmeister’s worst nightmare. It usually starts out as people enjoying watching, feeding and caring for them and in a couple of years the pond experiences excessive algal and aquatic plant growth from geese feces nutrient-loading.
Unlike most birds, Canada geese eat grass, up to four pounds a day per goose. They like to feed where grass is low and visibility long-ranging, for a good view of any approaching predators…which describes ponds, lakes, golf courses, parks, playgrounds, schools, soccer fields, and airports.
The overall impact of geese waste in ponds depends on several factors including size, depth turbidity, fetch, natural chemistry (oligotrophic versus eutrophic), the abundance of geese and the rate at which other nutrient sources (fertilizer runoff, manure from livestock, sewage, etc.) including organic matter (leaf and grass cuttings) enter the pond.
I have found if there is an excessive growth of algae and aquatic plants in a pond, that it is usually associated with increased nutrients (nitrogen and phosphorus) from some source. Several peer-reviewed papers have studied the effect of goose feces on water chemistry. Manny et al. (1975, 1994) was the first to assess nutrient contributions to lakes by geese. They estimated the total contribution to nutrient-loading in a lake from geese was as high as 40% of the nitrogen and 85% of the phosphorous. Other researchers supported these findings.
Unckless and Makarewicz (2007) published studies suggesting these claims were not correct from conducting a series of mesocosm (mid-sized environment) experiments. They found goose feces simply sank to the sediment where it eventually became part of the benthic detritus food web. This led them to suggest that goose feces were unlikely to have immediate impacts, but that over time the buildup of nutrients in the sediment may have significant effects on the water body. They did suggest these nutrients could be cycled back into the water column during a mixing event and stated that greater research was needed to determine the fate of goose feces in the sediment.
Their research was not representative of limnology in small shallow ponds, where wind plays a greater role in mixing water masses than the annual fall overturn. In shallow ponds, where geese feces continuously enters surface waters, we all agree some portion may be dissolved and/ or sink to the bottom, and over time dissolved N and P increases in concentration by undergoing anaerobic denitrification and/or nitrification until mixed by wind back into the warmer surface photic zone making them immediately available for algal and plant growth.
Hamilton, VA Pond
My worst goose pond problem began with a call more than three years ago to make a pond site visit in Hamilton, Virginia (about 45 miles west of Washington, DC) that had a major algae and aquatic weed problem.
On my site visit in June, 2007, I noticed the pond had more than 40 geese and the grass banks lining the pond were covered with goose feces 5-6 feet out from water’s edge, and in several areas the banks were totally eroded for easy geese entry. The pond has extensive lawn areas on three sides with a large home and
|reflection-style swimming pool on the front side. It is an exquisite pond, over two acres with an island in the center, built by someone who knew how to build ponds. This pond is the flagship and home of Donald Nordgren, the President of D&D Landscaping, Inc., (http://www.ddlawnservices.com), |
Falls Church, VA. The pond was covered with along the banks, see photo below. watermeal and had spirulina (filamentous) algae I learned that this pond sometimes has more than 100 geese on the water and surrounding area and more than 30 often overwinter. Donald’s children love having geese on the pond and the property next door is aptly named “Goose Hill”. Behind this property is a five or so surface acre pond. The entire area is full of small lakes and ponds and is a waterfowl haven. The impact of geese waste-loading on the pond is advanced eutrophication (nutrient overloading, with excessive algal and aquatic plant vegetation). If the pond did not have a large fountain in it, there would have been summer fish kills from oxygen depletion.
Mother Nature would say that having a big flock of geese or ducks visit or live in your pond is the highest compliment your pond can have, it’s the ultimate peer review. The Hamilton Pond has an island in the middle of it. Construction contractors love building ponds with islands in the center. It reduces the volume of dirt that they have to handle and owners like the reduction in pond construction costs. But neither appreciate an island as much as the geese do, the island (bigger is better) provides resident geese safe nesting and roosting areas from predators.
Dr. Joel Brown, a biologist at the University of Illinois at Chicago, has
Here is an example of goose feces density on pond banks.
Until you get rid of some of the resident geese and reduce nutrient loading, the pond remains highly eutrophic and with the watermeal knocked out, Spirulina (filamentous algae) will become the dominant species and begin to cover the pond as shown here.
reported that geese defecate every seven to ten minutes and that over the course of the year this can equal 750 pounds of droppings per goose. That is more than two pounds per day per goose. (Golf course superintendents agree with this figure). The goose droppings are washed into the pond from runoff, causing nutrient over-enrichment, which expedites undesirable aquatic plant growth. The two photographs above are examples of the impact of resident geese.
Resident Geese Control – Addling the Eggs: What Humane Repellents Can a Pond Owner Use to Chase Away or Help Geese Migrate?
For resident geese, the approved and recommended approach is to addle the eggs to control their reproduction and replacement.
This encompasses weekly or even more frequent checking of nests and coating each egg with mineral oil to close off the oxygen to the fertilized yolk inside the egg, which then does not hatch. The female goose then sits on a non-hatchable egg and her interest in laying more eggs is turned off.
If you remove or crack the eggs, the female will lay more eggs. Over a three year period, using addling, resident geese on this pond were reduced from 30 to less than 7. Note: One problem here is that you have to chase the female goose off the nest and quickly coat the eggs with mineral oil and put them back in the nest before you get bitten. Mother Goose likes to bite you at their level if you are on your knees working on eggs; you may get bit in the ear…or rear. Also, you have to search for nests and eggs daily and it is a good idea to write the date on the eggs. A good tool to protect you from attack by a nesting mother goose is an open umbrella.
The other problem is that geese can figure out you are doing something to the eggs and get creative with hiding and placing nests in adjacent neighboring areas and then move the goslings to the pond.
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Be on guard because Mother Goose likes to bite.
You will have to check daily for nests and eggs.
Geese Repellent Technologies in the Marketplace
Migratory Goose Repellent Sprays for Grass Areas
MigrateTM Turf Spray, Taste Deterrent, (www. birdgone.com.goose.htm, Migrate* -AG 36 (www.beckerunderwood.com, and Sepro Flight Control Plus (www.flightcontrol.com).
Using Duck Decoys as a Goose Repellant
One observation over the years has been that geese and ducks do not like the same pond or even field, so I decided to put 15 duck decoys strategically placed in the Hamilton Pond.
A pair of live swans has been reported to chase geese and ducks out of even large ponds.
There are a group of different types of silhouettes (cloths – flags that move with a breeze) and solid shaped ones that can be purchased and placed around a pond. In Pennsylvania and New Jersey, they are extensively used on youth soccer fields to keep geese off the fields. Examples can be found at: http://www.gemplers.com/product/145539/ Coyote-Decoy-Two-dimensional-Goose-Repellent
The use of trained dogs has been reported to be effective. The Internet lists many suppliers and trainers of goose dogs. Using hunting-type dogs to chase Canada geese for population control is questionable in terms of ethics and humane concerns. These dogs have instincts to grab the birds, which can injure or kill them. Border Collies love to herd geese without biting or touching them, and have been reported to be both effective and humane for this job.
Canada geese like open, unobstructed spaces where they can watch for approaching predators. Not mowing to the waters edge and growing grass taller has been reported to discourage them from staying. It also helps to add taller plants to screen predators from view.
In Pond Boss, there is an advertisement for AwayWithGeese.com technologies.
They have been business for five years and have a bunch of success stories associated with ponds.
This technology has been appreciated by pond owners, golf courses, and playgrounds, sports fields, as noted in the testimonials on their website. It is a water sealed unit with a solar cell on top to generate a flashing light that bothers the geese at night to the point they leave.
What are the pros’ and cons’ of the above technologies and a few more? Advantages, cost benefits, can they be compared, or is it comparing apples and oranges? Do these devices and techniques have a specific windowof-opportunity of conditions that they work most efficient or best in?
The manuscript from this three year study is too long for one issue of Pond Boss, so we’ve divide it into two articles. The first (this one) is a description of the problem and methods and the second article (next issue) will be results of the study and comparison of different technologies, while a different article will focus on creative treatment of watermeal.
Manny, B, Johnson, W, Wetzel, R, 1994. Nutrient additions by waterfowl to lakes and reservoirs: predicting their effects on productivity and water quality. Hydrobiologia 279/280: pp 121-132.
Manny, B, Wetzel, R, and Johnson, W, 1975. Annual contribution of carbon, nitrogen, and phosphorous by migrant Canada geese to a hard water lake. Int. Ver. Theor. Angew. Limnol. Verh. 19: pp. 949-951.
Unckless, Robert & Makarewicz, Joseph, 2007. The impact of nutrient loading from Canada geese (Branta canadensis) on water quality, a mesocosm approach. Hydrobiologia
Mike can be reached at email@example.com.
|Hamilton Pond… |
Without Geese or Watermeal
by Michael A. Champ
Nutrient loading from resident goose populations has become a serious problem in different parts of the nation, especially the Northeast. This article is the second of two to discuss the strategy and technologies used, with their effectiveness as related to each technology’s window-of-opportunity to renovate a two-acre pond covered with watermeal.
The purpose of Part One (Pond Boss, Jan/Feb, 2011), was to discuss the impact of excessive nutrient loading from a large resident Canada Goose population, which produced eutrophication and subsequent abundant algal and aquatic plant growth in Hamilton Pond.
Today, a pondmeister can find perhaps a dozen geese repellent technologies on the Internet. These different products serve in some manner to make geese not want to feed on your lawn or playgrounds. They all have excellent and helpful websites but, how do you select one or more that will work best for you and your needs? Hamilton Pond, because of its size, design and rural location and the degree of accumulated impacts, required a unique strategy to separate the components of the problem into key factors linked to the cause and effect of excessive plant and algal growth.
The strategy includes the following steps: (1) Encouraging geese not to be residents, but continue their migration, (2) Treating and eradicating excessive aquatic plant and algal growth, and (3) Reducing and binding nitrogen and phosphorous in the water column and bottom sediments from goose-influenced nutrient loading. The goal was to make sure these nutrients are not recycled or released by biological or chemical processes into the photic zone, to stimulate future aquatic plant and algal growth.
Today a pondmeister can find perhaps a dozen geese repellent technologies on the Internet.
|When thinking about this, what you are trying to do is to slow down or halt natural ecological processes where a pond ages over time and evolves to a wetland, then grassland to a forest. Nature’s way is for surface sediment erosion and organic matter from plant growth to eventually fill a pond. In this case, we decided the pond needed to be treated with a settling and binding agent to remove excess nutrients from the photic (lighted) zone to suppress photosynthesis and plant cell division. The biggest challenge was how to do this inexpensively, which is the purpose of this project, and story of this article, without having to drain or dredge the bottom sediments to renovate the pond (see PB Article by Mike Otto, Jul/Aug, 2009). |
Factors which encourage migratory geese to become residents include: (1) available food, (humans feeding them), abundance of large local–lush mowed lawn areas (geese eat up to 4 pounds grass daily), (2) a pond with an island in the middle for safe (from predators at night) nesting, (3) large pond or lake with clean banks (mowed grass or no vegetation down to the water’s edge, which provides geese a good line of sight to see predators), (4) rural areas that have predator control programs, and (5) lack of regulated hunting pressure.
The purpose was not to test and evaluate geese repellents when this study was started, but the process of trying to eliminate the above factors one at a time. This line of thinking lead to the use of a series of goose repellent technologies that were used and evaluated - listed in the following table. Early on, it was realized each of these technologies had specific windows-of-opportunity in which, under certain environmental or use conditions, the technology itself was effective, something that may not be fully appreciated by the buyer or users.
For instance, in using any of the different predator silhouettes, they are inexpensive ($40 -$100 each, which is good), but they need to be relocated daily to be cost effective. If soccer coaches are required to relocate them daily for the privilege of using public playing fields, then the initial purchase cost is all that is involved. But that has to be factored into their window-of-opportunity when evaluating and comparing different technologies. Without relocation, silhouette effectiveness is limited. See table below.
|AwayWithGeeseTM Lights |
For a pond, the simplest and most effective technology to use was the AwayWithGeeseTM Lights. The technology is a water sealed unit with a solar cell on top to generate a flashing light that bothers geese at night and they do not stay.
The units are cost effective (if you consider labor and life span) and guaranteed for two years. Some lights sold five years ago are still working and the replaceable photo cell head is $149. They also have a land based unit. The unit provides continuous service year-round. The light automatically recharges itself in sunlight and will keep its charge for up to 6 days without sun. The recommended application ratio is one unit per three surface acres of pond that does not have an island or stream nooks that can be totally covered by one light. If you have an island like Hamilton Pond does, then two units are required for 100% water coverage.
The light from the unit emits about as much light as a 100-watt bulb and is not annoying to people. If you watch geese, there will be one goose on guard, head up and watching 360 degrees. I think the flashing light is a continuous distraction that interrupts geese from being on guard for predators and creates discomfort and/ or insecurity for them…a limnologist’s opinion.
Window-of-Opportunity for Technologies
All of the above tested geese repellent technologies were found to work. You need to select the technology with the most efficient window-of-opportunity for your specific en-vironmental conditions, time, use and money. See Table 1 at top of page 8 for comparisons.
Reduction in Shoreline Erosion from Goose Access
Common Cattail (Typha latifolia) were planted on one shoreline (200 ft) of Hamilton Pond to reduce bank erosion and goose access. Cattail growth was restricted laterally on the highly eroded bank area using rock barriers at each end of the planting to prevent root spread. You have to remove all the mature velvety,
brown flower heads the first week of September every year to control distribution. That can be a chore.
The water sealed unit contains a flashing light with solar cell which will hold a charge for up to 6 days without sun. |Pond Nutrient Reduction|
The pond was also treated with an MgOH treatment to reduce nutrients by forming stuvite crystals that will precipitate to the bottom of the pond. Struvite is a white crystalline substance consisting of magnesium, ammonium and phosphorus in equal molar concentrations (MgNH4PO4.6H2O). Struvite forms according to the general reaction shown below:
Mg2+ + NH4+ + PO4 3- + 6 H20
Common Cattail along the shoreline to reduce bank erosion and goose access. |The photograph above is of a struvite crystal which has a distinctive orthorhombic crystal structure. Brucite costs approximately $0.35 per pound plus shipping. I have used it in sewage treatment plants to dewater and settle digested sewage sludge. |
If someone is interested on research on nutrient chemistry and determining the dosage for assessing the effectiveness of Brucite in nutrient rich fish ponds, (think EPA NPDES Permits) please contact me. For more information, see papers by Higgins, and Novak, 1997; Sobeck, 2000; and Sobeck and Higgins, 2002. Brucite added to sewers prevents the formation of H2S and Sulfuric Acid, by serving as a weak buffer, (preventing corrosion below the thermocline), so may have many more applications in ponds.
|Watermeal and Spirulina Reduction|
Watermeal (Wolffia spp.) is considered by many to be the most difficult aquatic plant to eradicate in a pond. They resemble specks of green cornmeal floating on the water, feel gritty to the touch and are found in nutrient rich ponds that do not have high flow through water rates, because watermeal does not tolerate moving water (Lynch, Jr., 2004). Copper based algaecide treatments were used to clean up the Spirulina (Lynch, Jr., 2009).
Because watermeal floats, it occurred to me that you might be able to skim it off the water. So I developed a low technology (cost) approach with two pond prototypes. The first prototype (seen below) was a V-Shaped plexus glass funnel with side arms to direct and catch wind driven watermeal into the funnel, which sits about 1/4 inch deep in the water. The funnel is connected by tubing to a large diameter submerged pump (to pass debris) that then pumps water and watermeal into a sand filter. Its drawback is that the structure can be moved or turned over in high wind. A metal rod through an opening should prevent this, if I had thought of it then.
|The next prototype was designed to have less surface area exposed to the wind, using only cross bar tubing and vertical floats, with a large funnel hooked to the same pump, placed in the leeward end of the pond. Water and watermeal were skimmed off the surface and pumped to a garbage can filled with CertainTeed rock wool insulation (with holes in the bottom) to filter out the watermeal, which was dumped and replaced as saturated. |
Our plan worked quite well. Resident geese left, we were able to bind the nutrients and rid the pond of watermeal. Hamilton Pond now has the beautiful, pristine look of a healthy, new pond.
Someone said a picture is worth a thousand words, and the photograph on the cover of this issue of Pond Boss tells it all.
Protoype 2 with less surface area exposed to the wind.
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Click Here |References & Suggested Reading |
Lynch, Jr., W. E. 2004. Duckweed and Watermeal: Prevention and Control. OSU Extension FactSheet. A-14.04.
Lynch, Jr. W. E. 2009. Controlling Filamentous Algae in Ponds. OSU FactSheet. A-3-09. ht tp: / /ohiol ine.osu.edu/a- fact / pdf/A_3_09.pdf
Fleming, R. and H. Fraser. 2001. The Impact of Waterfowl on Water Quality - Literature Review. Ridgetown College - University of Guelph, Ridgetown, Ontario, Canada. 15p.
Higgins, M.J. and J.T. Novak. 1997. Dewatering and settling of activated sludges: The case for using cation analysis. Water Environment Research. (69):225-232.
Sobeck, D.C. 2000. Determining the Role of Cations in Bioflocculation of Activated Sludge. Master of Science Thesis in Civil and Environmental Engineering. Bucknell University. 23p.
Sobeck, D.C. and M.J. Higgins. 2002. Examination of three theories for mechanisms of cation-induced bioflocculation. Water Research. (36):527-538.
Mike can be reached at firstname.lastname@example.org.