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How Snows get the Blues
Rick Burts
For many years the blue goose was considered to be a separate sub-species of the snow goose. However, biologists now recognize that the blue goose is the same species but in a different color phase from the white snow goose. Biologists also recognize that the blue goose species has about seven different color intergrades, or varieties, and despite the term “phase” they remain blue their whole lives. The extreme eastern Arctic breeding grounds hold a majority of the blue phase geese with eight out of every ten geese being blue. As you move farther into the western Arctic breeding grounds this phenomenon diminishes until you have an all white population of lesser snow geese that breed in the Wrangel Islands.
There have been theories projected by hunters and authors that the blue goose is a cross between a Canada and a snow goose. Dr. Bruce Batt, the Chief Wildlife Biologist from Ducks Unlimited Inc., assures me that this is a common misconception. The real reason for the “blue phase” is called plumage dimorphism . Overall, plumage dimorphism is a rare occurrence in birds. While it is common in the population of lesser snow geese it is very rare to find it outside in other populations of light geese like the Greater and Ross' species. The blue goose was originally suspected to only exist in the Baffin Island population but due to forced copulation, and the expansion of traditional breeding grounds the gene pool has become very mixed up. This popular theory of evolution is all that biologists currently have to go on; proof of exactly how the blue gene was brought into the lesser snow goose population remains a mystery at this point |
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Although it can happen, it is extremely rare for the smaller Ross' goose to be found in a blue color phase. This rare anomaly in nature is thought to only occur from a hybridization of the Ross' goose and a blue gene carrying lesser snow goose. If you should ever be lucky enough to take a blue phase Ross' you will have shot yourself one of the rarest trophies in the waterfowling world. As far as today's research indicates there is no known evidence of the blue phase being found in greater snow goose populations.
The reason that plumage dimorphism is rarely seen in the western colonies of lesser snow geese is due to how a female snow goose picks her mate. When it comes time for the female to take a mate she almost always goes outside her colony to find him. While she searches for the right mate she recognizes the need to breed with a goose with the same color as her parents. This would make it highly unlikely that a white female from the western arctic breeding grounds in search of a mate would choose a blue mate from the eastern Arctic breeding population. When the couple is paired they will return to the female's colony to raise their young. They remain paired until one them passes away as divorce is very rare among snow geese. It appears that forced copulation or rape is not uncommon on the breeding grounds and it is feasible to assume that all lesser snow goose populations will eventually carry the blue phase gene due to this behavior. Just because the snow goose picks a mate of the same color as their parents it does not mean there are not mixed color phase pairs in the Arctic colonies. The way this works is that the blue gene is a dominant trait, so some couples of white geese will produce both blue and white off spring. When these blues from white parents go to look for a mate they will look for a white goose to mate with and vice versa which results in mixed color phases in breeding pairs. When the brood from these mixed color phase marriages look for mates biologists admit to being stumped as to what color phase mate is desirable. |
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So next time you put out your decoys remember the amount of blues likely to be passing through your area and mix accordingly. Spreads in the heart of the mid-continent lesser snow goose flyway should contain no less than one half-blue goose decoys in order to mirror the look of migrating flocks through the area. Hunters west of these areas should incorporate less blue decoys or none depending on how far west they are. Hunters that are hunting birds from the extreme eastern breeding population should mix in about twenty percent snow decoys in with their blue decoys. Having an accurate color phase reflection for the area you hunt will make a difference in the way geese look at your spread and the amount of birds you take.
Rick Burts
S.D.S. Hunting Camps
