You’re sitting outside at a waterfront restaurant and a few gulls swoop over and land nearby. Chances are, you and your companions will not marvel at their beauty and grace. In fact, you probably will shoo them away, worrying about them grabbing your food or pooping on your head.
The several species of gulls seen on the shores of the Gulf of Maine may not face extinction, but according to researcher Liam Taylor, the disdain the birds face—from regulators and the public alike—is unfair and unwise.
Taylor, an evolutionary biologist and ornithologist completing a doctorate at Yale, along with colleagues Wriley Hodge, Katherine Shlepr and John Anderson, published a report that argues gulls have been victims of management policies which, though well-intentioned, are not sound.
And as exacting as science may be, Taylor says, subjective biases have played a part in favoring one species over another.
Taylor said reviewing historical and ecological data resulted in no scientific support for the view that gulls are overpopulated in the Gulf of Maine region.
Their study suggests that gulls may be unfairly losing out in an “interspecies conflict,” perhaps because of mistaken assumptions about their populations.
Gulls, he said, are seen as “non-seabird creatures. There’s sort of ‘seabirds,’ and then there’s gulls.”
The report’s title bluntly signals where the researchers landed: “Interspecies conflict, precarious reasoning, and the gull problem in the Gulf of Maine.”
Gulls have been understood as pests or worse, Taylor says, for many decades.
In the 1950s and 1960s, A.O. Gross, an ornithologist at Bowdoin, led “indiscriminate nest destruction” efforts in the Gulf of Maine. Gross used a mixture of motor oil and formaldehyde and, with a pesticide sprayer, applied it to eggs in gull nests.
The concoction would kill the unhatched birds, Taylor explains, “but the gulls wouldn’t re-nest because the eggs would look viable.”
While working on his doctorate, Taylor completed an independent study on Great Duck Island off Frenchboro; the island is owned by College of the Atlantic. And study also was conducted on Kent Island off Grand Manan Island in New Brunswick; that island is owned by Bowdoin College.
“Contemporary conservation science requires mediating conflicts among nonhuman species,” the report notes, “but the grounds for favoring one species over another can be unclear.”
The students “examined the premises through which wildlife managers picked sides in an interspecies conflict,” it continues.
“Managers in the Gulf of Maine follow a simple narrative dubbed the ‘gull problem,’” the report asserts. “This narrative assumes Larus gulls are overpopulated and unnatural in the region. In turn, these assumptions make gulls an easy target for culling and lethal control when the birds come into conflict with other seabirds, particularly Sterna terns.”
Taylor said reviewing historical and ecological data resulted in no scientific support for the view that gulls are overpopulated in the Gulf of Maine region. And in fact, claims to the contrary originated “from a historical context in which rising gull populations became a nuisance to humans,” the report argues.
Seabirds breeding in the Gulf of Maine include several species of gulls: (Laridae: Larinae), terns (Laridae: Sterninae), and auks (Alcidae), as well as double-crested cormorants (Nannopterum auritum) and a small population of Leach’s storm-petrels (Hydrobates leucorhous), the report notes.
“Two of these groups, gulls and terns, have come into direct conflict. Large Larus gulls can disturb tern nesting behaviors, depredate nests, and even eat adult birds,” and so conservation managers have chosen a side in this conflict.
Another argument for acting to reduce gull populations, Taylor explains, is that their numbers are higher than they ought to be because of human interaction, such as the food they find in trash landfills. The research found only limited support for this conclusion, he says.
And historical data may not be of great value, the report suggests:
“It is possible that contemporary Gulf of Maine seabird diversity and breeding habitats are less than two centuries old. The historical record offers no guidance for a proper, stable, or long-term population size for gulls, terns, or any other seabird…”
The decision-making process on managing bird populations that are threatened or in decline became a focus of the work Taylor, Hodge, and Shlepr did.
“We’ve been treating certain birds as disposable,” Taylor argues. “We care about nature, and some birds are under pressure while others are disposable,” a position that didn’t sit well with the researchers.
“We need better reasoning. It may still be worth it to kill them, but not on the basis of foolish reasoning. No matter how much data you have you’re blind to your own biases,” he says.
Regulators must separate gull numbers from the consideration of what they are worth in the ecosystem, Taylor says. He and his colleagues became immersed in “tricky” ethical questions and began examining the intuitions that regulators perhaps allow to influence them.
Eagles, for example, are considered noble, majestic birds, yet their habits are “much more scavenging that was imagined.”
The study report is available at: conbio.onlinelibrary.wiley.com/doi/10.1111/cobi.14299
