Snow Goose Overpopulation Essay Research Paper The

Snow Goose Overpopulation Essay, Research Paper

The Overpopulation of the Snow Goose in North America

Abstract

The purpose of this paper is to explore available research on the overpopulation of the Snow Goose on the North American continent. The snow goose has been rising in population since the middle of the century and has been escalating so much it is destroying their natural habitat. Wildlife managers have just recently begun to implement strategies to combat this problem. Mainly through the use of hunters the managers are trying to curb the population growth.

Introduction

There are three main species of Snow Goose of primary concern. The Lesser Snow Goose (LSGO) is the must abundant and at the same time most troublesome. Ross. Goose (ROGO) is very similar to the Lesser and can only be distinguished by close observation. Both the Lesser and the Ross nest in salt marshes along Hudson Bay and then migrate down to the gulf coast states such as Texas and Louisiana. Their populations number in the millions. The third sub species is the Greater Snow Goose. They nest in the same marshes as the others except they migrate down the Atlantic Coast into the Carolinas and that vicinity. All three species have exploded in numbers since the 1950.s. Researchers have done a lot of study on the numbers and the degradation but may need to do more studies on the impact to other species and look for other options to control the populations.

Population Trends

The numbers of all "light" colored geese has been on the rise since data was first collected. The Lesser Snow Goose (LSGO) has drastically increased in number since data was first taken. Numbers range from around 800,000 in 1969 to as many as 6 million in 1996 (CWS 1999). While the Greater Snow Goose (GSGO) has risen in numbers from a few thousand to almost 500,000 (CWS 1999). This brief article did not provide much insight into actual numbers. Abraham and Jeffries in their report dig deeper and provide more significant and detailed population counts. Their numbers add in the Mid-winter index, which is the number of geese counted during mid-winter and referred to as MWI. Their numbers also have a count for Ross. Goose (ROGO) which primarily flies with the (LSGO) and is very hard to distinguish (Abraham and Jeffries 1998). They too suggest the LSGO population to be around 800,000 in 1969 and in 1994 about 2.4 million. Although it is suggested that the number is low due an undercount during the winter and a more precise count may be taken when nesting in spring. The population of Greater Snow Goose has reached 612,000 from around 50,000 in the mid 1960.s. Ross. Goose has increased from 8,000 in 1957 to nearly 500,000 in 1995 (Abraham and Jeffries). The Texas Department of Fish and Wildlife states that the population of wintering snow geese has remained constant. They imply this is due to the fact that the geese have spread their winter range into other states (TWDS 1999). As indicated earlier it is very hard to count wintering birds because such a large number of wintering areas. Below are a few graphs of these population trends

(CWS 1999)

(Ingstrup 98)

(Ingstrup 1998)

Factors contributing to High Population

The snow goose problem is a wildlife manager’s nightmare. Through prudent restrictions on birds taken as game, and the increase in refuges coupled with excellent habitat in the birds entire range. It is estimated that there is nearly 900,000 ha of rice fields over the snow goose.s winter range (Abraham and Jeffries 1998). This is in addition to the typical salt marsh wintering ground. Abraham and Jeffries suggest that farther to the North in states like Nebraska and North Dakota the conversion of grassland prairie into cereal grains has provided a tremendous amount of food for the geese. In addition it has also blurred the area typically considered the wintering range. It may also provide a natural rest stop along the way for migrating birds assuring greater health at nesting grounds (Abraham and Jeffries 1998). The establishment of refugees has reduced the amount of birds taken by hunters allowing more birds to complete a full migration cycle (CWS 1999). Hunting of the Greater Snow Goose was banned in the us from 1931-75 (Abraham and Jeffries 1998). Hunting was not allowed to promote population numbers, and once started in 1975 did not have a high harvest. The LSGO and ROGO starting in the middle of the 60.s and continually have extended their nesting range south into less extreme climate (Abraham and Jeffries 1998). It has also been suggested that since birds are now living longer the older adults are now leading the less wary young to safer sites and out of hunter’s range (Ingstrup 1998). Ingstrup also suggests that the artic may be warming and as Abraham and Jeffries cited there has been shown a correlation between the snow melt and survival of nesting birds and their young. According to Hodge the annual kill by hunters in 1970 neared 40% but in 1994 the rate had dropped to less than 8%. Thus allowing a great deal of the adult population to return to nesting sites in the spring.

Impact on habitat

The snow geese still nest in a primarily salt marsh environment. The geese have a detrimental feeding behavior in which they pull up the marsh grass by the roots. This behavior is know as grubbing and when done