Too Many Snow Geese

Times Have Changed and It Ain't Easy

Many people may wonder why the snow goose hunting season is open in the late winter when snow geese are moving north toward the breeding ground. Some concern has been expressed that waterfowl managers have reinstated a spring hunt, one of the first things outlawed early in this century to protect depressed waterfowl populations. As can be said of tractors and the things being taught in school, "Times have changed and it ain't easy."

Waterfowl managers are faced with a problem unimaginable just a few years ago - too many geese. In some East Coast states, and more recently in the central United States, managers have been dealing with "too many" resident Canada geese for several years; but dealing with an over-population of a bird that migrates through three countries is new; and its a large challenge.

As is often the case, the first challenge involves communications and answering the question "Is there a problem at all?" A related question is "Even if there are too many snow geese, isn't it just a snow goose problem?" If those questions can be adequately answered, the obvious third questions is: "What can be done to solve the problem?"

A management plan written in 1982, when the Mid-continent breeding population was 1.7 million, specified a desired breeding population size between 800,000 and 1.2 million birds. The winter count crossed the two million mark in 1991 - the 1995 estimate was 2.7 million. Those numbers confirm that the snow goose population is growing but they don't document a problem. However, the 1982 Management Plan suggested that the "Mid-continent snow geese may have exceeded the carrying capacity in some colonies ..." Ongoing research has confirmed that the carrying capacity of the habitat in some areas has been exceeded to the point that "permanent damage to tundra vegetation" is occurring. In addition, and because of the amount of vegetation removed by snow geese, the salt content of remaining soils has increased, killing all vegetation. The effect is so widespread and significant that it is easily observed in data collected by satellites.

As a result of over-population and degraded habitat quality on some portions of the breeding ground, snow goose goslings in some areas are smaller than goslings 15 years ago. Gosling mortality is high and diseases such as coccidiosis kill many of goslings and can affect other birds. Survivors remain small as adults and may be less able to withstand the stress of migration. Colonies are moving inland and to other Arctic coastal areas. Adults are surviving at a high rate thus shifting the age structure of the population toward older geese - a dangerous situation. Old birds may be more susceptible to disease and a cholera outbreak might spread quickly. If a population crash occurs, there will be few young, strong geese to begin the rebuilding process.

Species such as yellow rails, scaup, shovelers and wigeon, which use the same habitat as snow geese, were once common but can no longer be found in areas denuded by white geese and there has been a significant decline in the number of breeding semipalmated sandpipers.

Snow geese are likely carriers of avian cholera, a highly contagious disease that has occurred annually in Nebraska's Rainwater Basin region since 1975. A large proportion of the birds picked up each March are snow geese but essentially all other species of waterfowl present are also found dead. Since Nebraska plays an important role in the life cycle of a large number of migratory birds by providing migration habitat, many species are at risk should a major outbreak of cholera occur.

Scientists, using the data briefly described above and other information, believe the snow goose population is in trouble, and birds other than snow geese have been negatively affected and are in jeopardy. The next logical step is to identify solutions.

The Management Plan identified hunting as the primary tool to control the size of the snow goose population. In the mid-1980's the daily bag limit in the Central Flyway was five birds and there was an 86 day season. In 1990, the bag limit was changed to seven and in 1992, to 10. Also in 1992, the season length was increased to 107 days, the maximum allowed under the Migratory Bird Treaty. During this period, the ending framework date - or latest date on which hunting could occur - was the "Sunday nearest 15 February." Increased harvest has not followed with the more liberal seasons. Between 1970-79, the average annual harvest of snow geese was 258,000 in the Central Flyway. Between 1980-89, the average was 241,000. The average for the period 1990-94 was 230,000. In 1995, the ending framework date for the snow goose season in a portion of the US was extended to 10 March, another limitation imposed by the Migratory Bird Treaty. The area where the season can be open until 10 March was expanded for 1996-97. Biologists are uncertain about the effect on harvest of this expanded hunt.

The problem of the over-population of snow geese is one of international significance. Therefore, it is appropriate that the Arctic Goose Joint Venture (AGJV) under the North American Waterfowl Management Plan is involved in its resolution. At their October, 1996 meeting, the AGJV considered a list of items intended to reduce the population of Mid-Continent Snow Geese. Since reducing populations is not the usual objective of waterfowl management, some items on the list are foreign to many people - some are controversial. The list includes yet further relaxation of hunting regulations (e.g. allowing electronic calls or baiting) and changes in refuge management. Some recommendations can be implemented quickly - others will take a year or longer. Times have surely changed - goose management and particularly snow goose management has become more complex. If wildlife managers and the public can keep up with the changes and meet the challenges together, we have a chance to avert a major ecological disaster.

Briefly Speaking - Philosophy

"At First Glance..."

"At first glance, snow geese seem to be a species with a destiny of there own making, but they are only opportunists reacting to man's changes on the land. In the end, they will prosper or fail depending on the changes men make in the future." (Farrar, Jon. 1990. Snow Geese... A Riddle Wrapped in a Mystery Inside an Enigma. NEBRASKAland Magazine. October 1990).

Purists might argue that snow geese would be fine if man just left them alone. Perhaps so. But we humans have had a dramatic effect on the landscape and snow geese have "adapted" to take advantage of "management" actions. While snow geese - the "Nature" component - have certainly participated in their population growth, man and his actions have as certainly played a role. Just as certainly, man will have to take some new actions to stem the population growth or Nature's component will turn from contributing to population growth to causing a population crash.

But perhaps before we begin to look for management options, we should seek agreement on if a problem exists. The answer is somewhat dependent on the point of view taken. If one only views the snow goose population size, then perhaps there is no great problem. In other words, there are still places for new colonies of snow geese on the nesting grounds. Birds are not using all of the refuges and habitats available to them along the migration route. Perhaps they could still find space along the coast of the Gulf of Mexico in the winter.

But from the viewpoint of the professional biologist community, there would be a resounding "Yes!" to the question, "Is there a problem with the snow goose population size?" Scientists are using phrases like "trophic cascade", "permanent damage to fragile Arctic ecosystems", "setting the stage for catastrophic disease outbreaks" and "many other species of migratory birds are negatively affected."

A trophic cascade is a situation affecting nutrition that perpetuates itself - in this case, where geese have removed the eatable vegetation leaving bare soil, the salt content of the soil increases, thus killing other plants. This increases the salinity further and allows salt intrusion inland. As more plants die, the areas yet further inland become more saline, killing more plants, and on and on. The "permanent damage" phrase results from data on experimental plots within which geese have not had access for greater than 15 years and there has been no recovery of the vegetation. Besides the extensive effect of a disease called coccidiosis, which annually kills a large number of goslings, the data base that establishes snow geese as carriers of avian cholera is growing. Cholera has killed birds in areas ranging from the breeding ground to the wintering ground and is a particular threat in Nebraska's Rainwater Basins during the spring migration. When cholera occurs, all species of birds present are potentially affected - not just snow geese. It is this aspect of disease as well as the loss of breeding habitat that demonstrates the negative affects on a number of species of migratory birds.

There is much detailed information affirming that there is a problem with the number of snow geese. And with that recognition comes a quest for solutions. This effort is underway at the International level and is being felt all the way down to the state and local level. For example, Nebraska hunters have witnessed more and more liberal hunting seasons. In October, 1996, the Arctic Goose Joint Venture under the umbrella North American Waterfowl Management Plan, considered actions which man might take to reduce the population size of snow geese. Some of these actions are counter to a historical way of thinking by waterfowl managers, administrators and the various publics involved in migratory bird management. Some are certainly in the "controversial" category. Ways to increase mortality and reduce production are "on the table." as opposed to the usual management actions associated with increasing populations.

Nature will have her way with the snow goose population. However, man has had his collective hand on snow geese for many decades and we should not lift it yet. We must pursue well thought out solutions to this problem. Not all the potential solutions will be palatable to everybody. But we must take responsible action now.