Who would have thought 25 years ago that the Ivory Gull might soon face extinction caused by human activities? If ever a bird existed whose habits seemed to render it immune to our destructive effects on the environment, surely it was this one. The Ivory Gull nests as far north as any bird in the world, often laying its eggs on nunataks—sheer mountain peaks surrounded by glacial ice. During the frigid Arctic winter, it moves south just far enough to escape the complete darkness cast for months nearer the pole. In the company of ice, wind, and polar bears, the ghostly Ivory Gull plies the edges of twilight frozen seas where few people venture.
Today it is all too clear that close proximity to humans and an industrialized society is not a prerequisite for suffering their ill effects. Some of the most remote regions of our planet, those nearest the poles, are among the first to be facing profound, climate-driven ecological changes. The Ivory Gull’s year-round association with sea ice and its position at the top of the Arctic food web make it especially susceptible to these changes and to environmental pollution swept north by prevailing winds and ocean currents. Recent surveys in Canada revealed an 80 to 85 percent population decline in the species’ breeding population there since the 1980s, raising concern for the survival of the species and rumors of its imminent demise. Researchers are scrambling to understand the ecology and status of this enigmatic and exceptionally difficult to study bird and answer the question that everyone has been asking: What is really happening to the Ivory Gull? Although it seems unlikely that any one factor is driving the bird’s apparent decline, scientists are slowly assembling the pieces, and human activities are certainly implicated.
The Ivory Gull was discovered in 1609 by English explorer and whaler Jonas Poole. Despite its early discovery, the bird’s northern haunts and its rarity away from its scattered breeding colonies have left it one of the world’s most poorly understood seabirds. Today, researchers face enormous financial and logistical obstacles in their efforts to find and study the species in its remote breeding colonies in Arctic Canada, Greenland, Svalbard (Norway), and Russia. Studying the winter ecology of the Ivory Gull in the icy North Atlantic and Bering Sea has not yet even been attempted in earnest, thus baseline data on the bird’s past and present population sizes, migratory behavior, and winter foraging habits are still largely unavailable. This poses significant problems for researchers as they try to nail down the species’ population status and trends. Finding and counting all of the Ivory Gulls in any given year is simply impossible.
In the Canadian Arctic, where relatively good historical data on Ivory Gull populations does exist, thorough systematic surveys are now being accomplished for the species on a regular basis. As a result, scientists have found that the breeding population of the Ivory Gull in Canada has plummeted by as much as 85 percent since the early 1980s. Once numbering an estimated 2,450 breeding pairs, only 500 or fewer are known to exist there today. Breeding colonies that traditionally held hundreds of pairs from year to year are now abandoned; the few remaining colonies are steadily declining or harbor just a few isolated pairs. The only Canadian Ivory Gull populations that researchers believe have any chance of surviving are those on northeastern Ellesmere Island, where a number of previously unknown colonies have recently been discovered, and on tiny Seymour Island, which has a colony of 60 to 70 pairs at the species’ westernmost breeding location.
What scientists cannot say for certain is whether some birds have moved elsewhere to breed or whether the population is simply dying off. Although the latter is considered the most likely scenario by most scientists who study the species, the Ivory Gull is genetically similar across its entire world range, suggesting that dispersal and recolonization of other breeding sites may be a regular part of this species’ life history. Recent satellite tracking of birds in Greenland and Norway confirms that individuals do occasionally breed in different colonies from year to year, but also that birds typically return to the same general areas to breed.
As encouraging as the discovery of new colonies on Ellesmere Island was in 2006, though, the nest-associated vegetation at the sites suggests that the colonies have existed there for a long time and are probably not made up of individuals from other areas, as many researchers had hoped.
In the Old World, where consistent historical data are lacking and the bulk of the world’s remaining Ivory Gulls breed, population trends are still unknown and of great concern to scientists. Researchers launched an annual survey in 2006 in Svalbard, Norway, but they have yet to detect any definitive recent population trends. Preliminary findings suggest that the species has declined over the last century and that the breeding population there was previously overestimated. Researchers now estimate that only 350 to 650 pairs remain there. Another ominous discovery is that many of the large historical colonies previously known in the region—particularly those on flat ground—are gone, and other colonies have fewer individuals than they did before.
Without question, the Ivory Gull’s stronghold lies on the remote islands scattered in the Barents and Kara seas in the Russian Arctic, where 85 percent or more of the bird’s world population now breeds. Long-term population trends for this region are completely unknown, and although populations at several key colonies appear to be stable, populations at other colonies fluctuate widely from year to year. In some cases, colonies hold as few as a couple dozen pairs one year and many hundreds the next. Whether birds that nest in these colonies are just not breeding in some years or whether they are breeding elsewhere is still unknown. In all, colonies in Russia may support 4,500 or more breeding pairs.