Goose egg addling

Types of addling

The most common method of egg addling is oiling, in which an egg is coated with an oil (usually food-grade) to deprive the embryo of oxygen, preventing it from forming any further. In Canada geese and cormorants, 100% corn oil is used,{{Cite web |date=October 2022 |title=The Use of Egg Addling in Wildlife Damage Management |url=https://www.aphis.usda.gov/sites/default/files/16-egg-addling.pdf |website=United States Department of Agriculture}}{{Cite web |last=McGlashen |first=Andy |date=6 February 2020 |title=Without Solid Science, Government Plans to Expand Cormorant Killing Methods |url=https://www.audubon.org/news/without-solid-science-government-plans-expand-cormorant-killing-efforts |website=Audubon Society}} as it is relatively cheap compared to other oils.Pochop, Patricia A. (January 1998) "Effectiveness of Several Oils to Reduce Hatchability of Chicken Eggs." The Journal of Wildlife Management, 62(1) 395-398. Other oils known to be effective include castor, linseed, safflower, soybean, and white mineral oil.

File:Canada Goose Eggs.jpg

In addition to oiling, eggs may be shaken or punctured. Puncturing is considered less reliable by the U.S. Animal and Plant Health Inspection Service, and so it is not used as often. Shaking is also unpopular as, if done incorrectly, it can result in the hatching of deformed goslings.{{Cite news |last=Spears |first=Tom |date=16 June 2015 |title=Shell-Shocked: Shaking eggs can deform baby geese, experts say |url=https://ottawacitizen.com/news/local-news/shell-shocked-shaking-eggs-can-deform-baby-geese-experts-say |work=Ottawa Citizen}}

OvoControl G is a drug containing nicarbazin, originally developed as a drug for treating coccidiosis in chickens, that comes in a wheat-based bread which the bird takes orally. It has been proposed for Canada goose control, as its side effects include reduced clutch numbers and a low hatch rate.Caudell, Joe N. (May 2010) Using a Cost-Effectiveness Model to Determine the Applicability of OvoControl G to Manage Nuisance Canada Geese. The Journal of Wildlife Management, 74(4) 843-848 Unlike egg oiling, OvoControl G does not require nests to be tracked down, and fewer people are needed to lay the bait, giving it an advantage over oiling.Bynum, Kimberly S. (February 2007) Nicarbazin OvoControl G Bait Reduces Hatchability of Eggs Laid by Resident Canada Geese in Oregon. The Journal of Wildlife Management, 71(1)135-143

Implementation

Addling must be done early in an egg's development, or else the embryo will be too far along for the oil to have an effect. The date varies depending on the bird. A Canada goose egg is generally considered too far along for addling at 14 days. A study on herring gull eggs using petroleum found that if an egg is 28 days past laying, even as much as 100 μl of petroleum will fail to have an effect.Lewis, Stephen J. (July 1984) Effect of Egg Oiling on Larid Productivity and Population Dynamics. The Auk, 101(3) 584. Egg age is determined by doing a "float test". The egg is placed in a bucket of water, and if sinks, it is young enough to be addled. A floating egg is too old. Additionally, if an egg has a crack in it, the entire nest it is in must be left alone.{{Cite news |last=Morelli |first=Brian |date=26 April 2017 |title=Oiling eggs latest strategy to control goose population in Cedar Rapids |url=https://www.thegazette.com/government-politics/oiling-eggs-latest-strategy-to-control-goose-population-in-cedar-rapids/ |work=The Gazette (Cedar Rapids, Iowa)}}

Locating nests and addling the eggs can be labor intensive, and may discourage its implementation.Brussee, B. (June 2018) Reproductive success of Common Ravens influences nest predation rates of their prey: implications for egg-oiling techniques. Avian Conservation and Ecology, 13(1) 17. Many egg addling programs rely on volunteers to find nests and treat eggs.Solomon, Adina (6 October 2022). [https://www.smartcitiesdive.com/news/canada-geese-overpopulation-urban-management-strategies/633359/ When Canada geese swarm cities, officials flock to solutions.] SmartCities Dive.{{Cite news |last=Ernst |first=Annie |date=8 March 2013 |title=Volunteers Sought to Help Solve Cupertino's Goose Poop Problem |url=https://patch.com/california/cupertino/volunteers-sought-to-help-solve-cupertino-s-goose-poop-problem |work=Patch}} Some places, such as British Columbia's Okangan Valley, may have a hotline or email address with which the public can report a goose or nest sighting.{{Cite news |last=Assman |first=Bowen |date=4 April 2025 |title=Egg-addling shakedown keeps B.C.'s Canada goose population in check |url=https://www.mapleridgenews.com/news/egg-addling-shakedown-keeps-bcs-canada-goose-population-in-check-7925368 |work=Maple Ridge-Pitt Meadow News |pages=}}

File:Canada goose goslings in nest - DPLA - e93f75139e72bda65b1d7a345161a42b.jpg

The crash of US Airways Flight 1549 on January 15, 2009, after an investigation, was found to have been caused by a bird strike of Canada geese. Subsequently, public opinion on the Canada goose shifted towards hostility, with publications such as The New York Post calling for reductions in the birds' populations. Even among animal rights groups, which generally oppose culling, the sentiment that numbers should be reduced was shared, with egg oiling proposed as a humane way to achieve the goal.Phillips, Matthew (20 February 2009). [https://www.newsweek.com/even-friends-goose-cooked-82275 Even to Friends, the Goose is Cooked]. Newsweek. Retrieved 17 June 2025. In the following weeks, an estimated 1,739 goose eggs were coated with oil in an effort to prevent any similar incidents from occurring.{{cite news |url=https://www.nytimes.com/2009/10/03/nyregion/03geese.html?_r=1&partner=rss&emc=rss |title=For Culprits in Miracle on Hudson, the Flip Side of Glory |first=Simon |last=Akam |newspaper=The New York Times |date=October 4, 2009 |archive-date=November 7, 2016 |access-date=September 5, 2018 |archive-url=https://web.archive.org/web/20161107081628/http://www.nytimes.com/2009/10/03/nyregion/03geese.html?_r=1&partner=rss&emc=rss |url-status=live }}

After their eggs have been oiled, geese will remain at their nests, even well after the time the eggs would have hatched.Beaumont, Matthieu (September 2018). Behavioral Response of Canada Geese to Egg-Oiling and Nest Removal. The Journal of Wildlife Management, 82(7) 136. Depending on the desired outcome, this can be seen as a pro or a con. If the goal is to keep geese isolated, oiling would be a good solutions, but if the goal is to get geese to leave the area, oiling would be a poor choice.

File:Ring-billed gulls in Red Hook (42792).jpg

Since the 1980s, egg oiling has been used to control American herring gulls. Unlike Canada geese, the gulls usually abandon their nests if the eggs fail to hatch, and their clutches are generally more likely to be lost to predators if they have been oiled.Blackwell, Bradley F. (2000) Early Loss of Herring Gull Clutches after Egg-Oiling. Journal of Wildlife Management, 28(1) 70-75 Ring-billed gulls have also been managed in this way, though results have been mixed; one study found that colonies do not leave the treated area, and the authors did not recommend oiling as a control method,DeVault, Travis L. (2014) Influence of egg oiling on colony presence of ring-billed gulls. Human-Animal Interactions, 8(1) 22-30. while another found that it caused a population decrease and called the oiling "beneficial".Engemen, Richard (April 2012). Egg Oiling to Reduce Hatch-Year Ring-Billed Gull Numbers on Chicago's Beaches During Swim Season and Water Quality Test Results. EcoHealth 9(2) 195-204.

Double-crested cormorants are very frequently targeted for egg addling, as their fish diet is viewed as a threat by the angling and aquaculture industries, and because they produce acidic guano that can damage property. When their eggs are oiled, most cormorants will not renest, and those that do are often unsuccessful.Dorr, Brian S. (2012) Summer and Migrational Movements of Satellite-Marked Double-crested Cormorants from a Breeding Colony Managed by Egg Oiling in Lake Ontario, New York. Waterbirds, 35(1) 114. Egg oiling is more cost effective than culling, further adding to its desirability as a management technique.MacGregor, Andrea M. (2012) Cost Effectiveness of Egg Oiling Versus Culling for Reducing Fish Consumption by Double-Crested Cormorants in Lac La Biche, Alberta. Waterbirds, 35(1) 66. Oiliing of cormorant eggs, however, is ineffective if enough fish (especially aquaculture escapees) are available to sustain the population.Ridgeway, Mark S. (May 2012) Responses of double-crested cormorants to a large-scale egg oiling experiment on Lake Huron. The Journal of Wildlife Management, 76(4) 740.

File:Passer montanus malaccensis @ Kuala Lumpur, Malaysia (1).jpg

Egg addling can also be used to control predatory birds. When a population of common ravens gets too large, it can lead to increased predation and population decline on other birds. Raven eggs are thus oiled to allow the prey birds to recover their populations.

In addition to managing native nuisance species, oiling can be used to prevent the further spread of invasive species. House sparrows, invasive in North America, have been controlled by treating their eggs with canola oil. This results in a complete prevention of hatching.Fernandez-Duque, Facundo (December 2019). Egg oiling as an effective management technique for limiting reproduction in an invasive species. Avian Conservation and Ecology, 14(2) 20. The Cornell Lab of Ornithology recommends oiling as a management solution for house sparrows and European starlings.[https://nestwatch.org/learn/all-about-birdhouses/managing-house-sparrows-and-european-starlings/ Managing House Sparrows and European Starlings.] Cornell Lab of Ornithology.

File:Canada goose on her nest (41052618365).jpg

Many animal rights and welfare groups support egg addling as a humane alternative to other forms of goose control, such as culling. Humane World for Animals supports egg oiling before the embryo is viable, and also supports removing eggs from the nest and replacing them with ceramics. People for the Ethical Treatment of Animals also endorses egg oiling, though it discourages puncturing or shaking.{{Cite book |title=Human Goose Control Solutions |publisher=People for the Ethical Treatment of Animals |pages=9}} Both organizations consider addling after the egg is 14 days old to be inhumane.

In 2021, the city of Rochester, Minnesota planned a volunteer-based egg addling program in Silver Lake Park. It was met with opposition by writer Greg Munson, who was concerned that after oiling, "there will be a handful of days, I'm guessing, not minutes or hours that that gosling will be suffocating before it dies, if it does die."{{Cite news |last=Petersen |first=Randy |date=13 April 2021 |title=Addling plan continues in goose management effort |url=https://www.yahoo.com/news/addling-plan-continues-goose-management-040100758.html |work=Post-Bulletin (Rochester, Minnesota)}} He further added that replacing eggs with ceramics would be more ethical. On the day of the addling, at least 25 people came in person to protest.{{Cite news |last=Petersen |first=Randy |date=15 April 2021 |title=Protest greets volunteer egg-addling effort in Silver Lake Park |url=https://www.yahoo.com/news/protest-greets-volunteer-egg-addling-040100325.html |work=Post-Bulletin (Rochester, Minnesota)}} The next year, egg oiling was done again, but with no protests reported.

In North America, birds protected under the Migratory Bird Treaty Act cannot be harmed or harassed; this applies to eggs and nests. The treaty does not include invasive species. In the United States, agricultural operations, homeowner's associations, and public land managers may addle eggs with federal permission. The United States Fish and Wildlife Service has a registration program for such cases.[https://www.fws.gov/ercgr/ Resident Canada Goose Registration]. United States Fish and Wildlife Service. Permits can be for the short-term or long-term. Short-term permits have been found other than be less effective, as the permit holders tend to treat just 5 or fewer nest on average, compared to the average 20 to 50 nests a long-term permit holder treats.{{Cite journal |last=Cope |first=Charles H. |date=2023 |title=Effectiveness of citizen engagement in a state agency egg-oiling program to reduce urban Canada goose populations and conflicts |journal=Human-Wildlife Interactions |volume=17 |issue=3 |pages=7}}

{{reflist}}

• [http://icwdm.org/handbook/birds/CanadaGeese/ControlTechniquesHome.aspx Internet Center for Wildlife Damage Management] {{Webarchive|url=https://web.archive.org/web/20130607062720/http://icwdm.org/handbook/birds/CanadaGeese/ControlTechniquesHome.aspx |date=2013-06-07 }}
• [http://mdc.mo.gov/your-property/problem-plants-and-animals/nuisance-native-wildlife/canada-goose-control Missouri Department of Conservation: Canada Goose Control] {{Webarchive|url=https://web.archive.org/web/20131019115804/http://mdc.mo.gov/your-property/problem-plants-and-animals/nuisance-native-wildlife/canada-goose-control |date=2013-10-19 }}
• [https://epermits.fws.gov/eRCGR/geSI.aspx Resident Canada Goose Nest and Egg Registration Site]

Category:Bird pest control

Category:Eggs

Category:Geese

Category:Methods of birth control

Category:Ornithological equipment and methods

• [https://epermits.fws.gov/eRCGR/geHome.aspx U.S. Fish and Wildlife Service - Permit Information Page]
• [https://www.youtube.com/watch?v=2CLIL-381Lw Canada Goose Egg Oiling Basics], an educational YouTube video produced by the USDA's Animal and Plant Health Inspection Service