How habitat destruction can sometimes lead to overpopulation.
By Michael Furtman
There once was a goose that seemed to ignore the ways of man. While the various subspecies of Canada geese adapted quickly to our taming of the land, and turned to feeding on waste grains in farm fields, light geese — Lesser Snow and Ross’s geese — continued their ancient ways of feeding in coastal marshes. Why, for nearly a hundred years, they ignored the feast that agriculture set for them is a mystery.
About two decades ago, though, that began to change. Light geese seemingly discovered the bounty that Canada geese had for so long enjoyed, and when they did, their life history changed forever.
It has become apparent that the limiting factor in snow goose populations had been the availability of foods in winter. After all, there’s but so much coastal marsh, and that amount of marsh has been in long decline across Texas and Louisiana. That would have spelled bad news for snow geese, except for their recent change in wintering habits and habitats.
The coastal marshes of Texas and Louisiana have historically hosted the majority of snow geese during the winter, with the white phase to the west and the blues to the east. Two things have changed dramatically in the last couple of decades. First, the color phases seem to mingle much more freely now than in the past, until the distribution is fairly uniform. Second, fewer and fewer geese are utilizing the coastal marshes, choosing instead to winter on the rice fields of Texas, Louisiana and Arkansas. Some groups can be found during December as far north as Missouri, Nebraska, Kansas, Iowa and Oklahoma. The food available in the agricultural fields certainly is an attraction. In addition, saltwater intrusion into many coastal marshes — largely due to oil exploration and man-made canals — has seriously diminished these once-vital marshes in size and quality. That may be enough to explain the shifting migration trends.
Switching to feeding on agricultural grains opened up a whole new high-energy food source, and with it came a change in breeding success. Because the land in the south could now support more geese, and more and healthier geese were heading back north to reproduce, snow goose populations exploded, to the point where they began to seriously impact their nesting grounds, causing damage to fragile environments that might take several decades (or longer) to recover. Snow geese use their short, powerful bills to dig out roots of plants. This grubbing in the fragile arctic tundra was not a problem until the recent population boom in snow geese. Now, they convert once-lush coastal flats into barren wastes of mud, and because the plants that once grew there helped keep soil salinity low, their absence resulted in dramatic increases in salinity, making rehabilitation nearly impossible.
Something needed to be done to reduce the population. Sure, eventually nature would take its course, and once the snow geese had destroyed their own nesting grounds, a collapse would occur. But waiting until then would mean the arctic landscape would be forever changed, and habitat needed by myriad other birds and animals would be ruined.
The solution, it turns out after much study, was to increase the harvest of snow geese through liberalized hunting.
“You’ve seen changes in agricultural processes that have put more food supplies on the ground on the wintering areas,” says Dave Morrison, waterfowl program leader at the Texas Parks and Wildlife Department.
“These birds typically existed in the coastal marshes, and what you have now is that they’ve expanded their range into agricultural areas where there’s a much more stable food supply through the crops that we’re planting. As a result, those birds were in better condition. They went back north in better condition to breed, produced more little ones. More young birds headed south… and this has been a compounding problem through time. Somehow or another we have to turn the numbers around and get them back more in line to where they should be.”
A Little Biology
The lesser snow goose, which the American Ornithologists’ Union classifies as Chen caerulescens caerulescens, was formerly classified as Chen hyperborea, which translates to the wonderfully romantic, “goose from beyond the north wind,” a great name that not only is descriptive, but also a shame to lose. But for many decades it was thought that the lesser snow goose and the blue goose were separate species. The blue goose was accurately described by the term “dark-blue goose,” or Chen caerulescens.
In the Northwest Territories, on the shores of Foxe Basin to the west of Baffin Island, the nesting grounds of the blue goose were discovered in 1929 after a six-year search by Canadian ornithologist Dewey Soper. This seemed to be conclusive proof of the separate species theory. As other colonies were discovered over the decades, researchers noted that many “snow geese” were nesting right next to “blue geese” and that even mixed mated pairs occurred. For decades it was assumed that these were closely related geese, capable of interbreeding, but still distinct. But in 1961 it was proven by Dr. Graham Cooch that the blue goose was a color morph of the lesser snow and that they were indeed the same bird. Both are now classified as the same species.
Both the white- and blue-phase snow geese have pink bills and rose-red legs when mature. Both have gray legs and bills when immature. In both color phases the sexes are nearly identical in plumage; the white phase is brilliant white with glossy black wing tips, while the immature snow tends toward sooty gray. A mature blue-phase snow goose can be strikingly beautiful with a slate gray body and a white head and upper neck. Such specimens are often referred to by hunters as “eagle heads,” a reference, no doubt, to the white head of the mature bald eagle. The immature blue, as noted earlier, looks much like an immature white-fronted goose — almost entirely brown-gray with a lighter underside.
Snow geese are not overly large geese, with most specimens weighing between five and six pounds. Despite that, they are powerful fliers; I have witnessed them plow steadily through a ferocious 40-mile headwind on their way to stubble fields to feed. Magnificent when traveling in huge flocks of a thousand or more, they fly in constantly changing waves, hence their common name of wavie. On 28-inch wings, they move very rapidly, quicker than Canada geese, and the wingbeat is nearly as rapid as that of some large ducks.
In flight they chatter constantly, more so than any other waterfowl. Theirs is a short barking sound, a high pitched yelp; they sound much like the war whoops heard in old western movies.
The majority of lesser snows nest in the Canadian arctic, with only a few spreading west into Alaska. The largest colonies nest in the eastern Canadian arctic, mostly in two huge conglomerations, one on Baffin Island and another on the west coast of Hudson’s Bay, on and near the McConnell River delta. By mid to late February the snows head for the nesting grounds, the male leading the female, halted only by inclement weather and lack of bare earth and ice-free lakes. Their impatience seems to cost them, for they make the flight south in a shorter time, the northerly migration a hop-scotch affair with the receding winter. Depending on which arctic nesting ground they call home, the lesser snow goose arrives anywhere from mid-May to early June. Even then, they find most of the ground still snow covered and they wait impatiently for the snow to melt. Since the arctic summer is short, their impatience seems justified; there is a very brief period of time to raise a family and prepare for yet another journey south.
A colony nester, the lesser snow will tolerate other nesting pairs as near as 15 feet away. Pairs bond at two years old, but it is birds three years and older that usually do the breeding. Mating takes place on the flight north. When they arrive, the mated pairs stake out their territory and vigorously defend it while the yearlings seek water nearby to wait out the summer.
Nest sites are near shallow lakes or rivers, on flat tundra plains, usually within a few miles of the ocean. Nests are used year after year, comprised of gravel, moss, grass, willows and down from the goose’s breast. In this she lays an egg a day for four days, although some nests can contain up to 10 eggs. Most lesser snow geese populations complete egg laying by the second week in June. Females rarely leave the nest during incubation and can lose a quarter of their weight. Some have been known to starve to death when performing their duties during periods of inclement weather. During this time the male stands guard against predators. In just over three weeks the eggs hatch.
Summers are lush but short in the far north. Able to swim and feed themselves within 24 hours of hatching, the goslings feed almost incessantly in the light of arctic days, when the sun almost never sets. They must grow quickly for the long flight south, and, within 40 days, in the company of their parents, they are winging their way to Texas.
Solving The Problem
Although the problem of habitat destruction is in the far north, the only real cure for it is in the south. Nothing can stop snow geese from breeding, but once they migrate to Texas and other southern states, hunters and the agencies in charge of wildlife management can impact the snow goose population.
In a snow flurry of controversy, including lawsuits by animal-rights groups, the U.S. Fish and Wildlife Service proposed liberalized hunting for snow geese as a means of reducing their population. Since 1999, this has meant longer seasons, including hunts in northern states in the spring, allowing the use of “unplugged” shotguns (waterfowling shotguns are normally restricted to a carrying capacity of three shells, with the remaining space in the magazine “plugged”), no possession limits and the use of electronic game calls, which are illegal in all other forms of waterfowling.
TPWD enthusiastically supported the proposal.
After five years of liberalized hunting, the question is, Has it done anything to reduce the population?
“Our 1998 midwinter population survey along the Gulf Coast put the number of light geese at 3.1 million,” says Jim Kelley, the lead biologist for the FWS on snow geese. “Last winter, it was about 2.3 million. The target is 1.65 million birds. We’ve been doing a pretty good job of reducing populations and have increased harvest to nearly 1.5 million geese in the Mississippi Flyway last year, and almost a million in the Central.”
The liberalized seasons were created through a process called a conservation order. Because of the lawsuits, Kelley is preparing an environmental impact statement.
“Until the EIS is published, there can be no more lawsuits,” says Kelley. “And until the EIS and its rules are released, there will be no change in our management strategy. The conservation order (liberal seasons) will remain.”
That means that for the upcoming winter season, light goose rules will remain relaxed, and are they are likely to stay relatively unchanged for the foreseeable future. That’s because even once the population is reduced to a sustainable level, it will need to be kept there. Backing off too soon would only allow the problem to repeat.
In the meantime, Texans are enjoying an increase in hunting opportunity, thanks to the longer seasons and generous limits. That doesn’t mean, though, that snow goose hunting is easy. Because they tend to be in flocks of thousands — even tens of thousands — getting them within shotgun range isn’t a simple thing. These large flocks tend to ignore all but the most massive of decoy spreads.
Not only that, but the geese seem to be changing their locations in Texas. Last year, for instance, the coastal prairies held less than half the snow geese they attracted just a decade ago, when wintering numbers approached 1.5 million. In 2003, only a third of that spent the winter in places like the El Campo area.
The reason is pretty simple. The geese that once thrived in Texas coastal marshes left those places as the marshlands deteriorated, and moved slightly inland to feed in rice fields. But rice farming isn’t what it used to be — the amount of land devoted to rice farming has declined 60 percent in the last decade. As a result, the distribution of birds has changed.
Despite the apparent relocation of many snow geese, Texas remains one of the premier goose hunting destinations in the nation. As long as the state maintains its habitat — whether man-made, such as rice fields, or natural coastal marshlands — we will enjoy seeing the majestic spectacle of tens of thousands of light geese winging their way through our skies.
The “goose from beyond the north wind” is here to stay. And that’s a very good thing, whether you like to watch them, hear them, or hunt them.