Ask anyone who has visited Bosque del Apache about this great National Wildlife Refuge and, odds are, the first thing they mention will be sandhill cranes.
Bosque translates to grove of trees. Bosque del Apache, in Spanish, means "woods of the Apache." The term comes to us from a time when Spanish explorers routinely found members of this southwestern tribe camped in the riparian forest along the Colorado River in central New Mexico.
The nearly 60,000-acre refuge, purchased largely with Duck Stamp dollars (funds generated through the sale of International Migratory Bird Stamps), was established in 1939. The land was set aside to provide for wintering migratory birds, especially greater sandhill cranes, which were endangered at the time. The refuge is also a breeding ground for many species including rails, shorebirds and the rarely seen Montezuma quail.
To be sure, with an average of 15,000 tall, elegant greater sandhills in the winter, these beautiful birds are the biggest draw between November and February. But many other avian species also call this place home in the winter, including a host of waders, a smattering of raptors, a few songbirds and more ducks that you can count. And there are many more snow geese than cranes.
Snow geese -- large white birds with black wing tips -- are divided into two subspecies: lesser and greater. Both experienced precipitous population declines during the 1800s, with overall numbers of greaters plummeting to as low as a couple of thousand individuals by the turn of the century.
Uncontrolled hunting was the cause. With protection from the International Migratory Bird laws and the establishment of National Wildlife Refuges such as Bosque, their numbers began to climb. Greater snow geese have experienced a satisfactory recovery. But the population of lessers has exploded with significant consequences both for the birds themselves and for millions of other birds with whom they share nesting habitat on the Arctic tundra.
Over the past dozen or so years, a number of articles have examined both the causes of this troublesome population increase and possible solutions. The reason for the dramatic increase in snow geese is generally believed to be an increase in the food supply during the winter, particularly on the prairies where there is an abundance of waste corn and other grains. Moreover, farmers with lands adjacent to National Wildlife Refuges are often paid to leave some of their crops for the benefit of cranes and geese. This abundance sets the stage for a high first-year survival rate, and may also increase productivity as most birds arrive on their breeding grounds in top condition. At the same time, waterfowl hunting -- which would help control the population -- has declined.
While some might consider a large and growing population of any species to be a good thing, the fact is that such a situation is usually not so good for other species that share the same habitat. In this case, many shorebirds (a family of long-distance migrants, most of which are already in serious trouble) are adversely impacted.
With a particular fondness for the tender roots of Arctic grasses and sedges, snow geese pull these plants out of the ground and leave pockmark scars.
Because the tundra regenerates very slowly, such foraging by large numbers of these big birds results in habitat destruction on a broad scale. Stilt sandpipers, Hudsonian godwits and other species have declined at least in part due to loss of foraging habitat and nesting cover on breeding grounds that they share with the geese. The situation represents, in the words of one writer, "Arctic ecosystems in peril."
If too many snow geese is a problem, then what is the solution?
Hunting seasons have been extended and bag limits expanded, but with a declining waterfowl hunting population, those efforts have not had the desired effect.
Biologists also remove some of the eggs from nests, but this is costly and time-consuming work.
Clearly, a permanent solution has not yet been found. But for the sake of a delicate ecosystem and the birds that are dependent upon it -- including the geese themselves -- one must be found.
