Some species find food by scent, expert says
Certain species use sniffer to find phytoplankton
You know it as the smell of the sea shore, but to wide-ranging oceanic birds with great sniffers, dimethyl sulphide is a sure sign of food ahead.
As Gabrielle Nevitt explains, dimethyl sulphide is created when krill consume phytoplankton. And some birds in the order Procellari-iformes — albatross, petrel, fulmar — are especially good at detecting dimethyl sulphide, perhaps up to 20 kilometres away.
They are called “fishes of the air” because they widely roam the oceans and come to land only to breed.
“Open up a textbook of ornithology and it’s quite likely it will say birds are one of the classes of invertebrates that lack a sense of smell,” said Nevitt, a researcher in the department of neurobiology at the University of California, Davis.
“It’s a false fact that found its way into the literature a long time ago, and people sort of accepted it.”
Nevitt is speaking this week in Vancouver at the academic International Ornithological Congress, which coincides with the public Vancouver International Bird Festival. Visit iocongress2018.com and vanbirdfest.com for more information.
Part of the festivities included Birds On Parade — stilters dressed as birds — leaving Harbour Green Park on Monday afternoon headed for Jack Poole Plaza.
Some birds eat the krill and others go after the fish foraging on the krill, Nevitt said. Research suggests burrow nesting species may place greater importance on smell than surface nesters.
The birds can emit a strong smell, too, which is thought to help detect one’s mate or parent. Pelagic seabirds mate for life and can live for more than half a century.
“They have a really strong scent,” Nevitt said. “When you’re holding them, they smell like a weasel. When I was on ships, they used to call me Stinky. That was my nickname.”
A researcher for more than 35 years, Nevitt started out studying salmon at the University of Washington in Seattle, specifically their ability to smell their way back to the spawning streams of their birth, then shifted to birds, despite some skepticism.
“I was surprised when I got into this how heavily ridiculed I was,” said Nevitt, who owns about 50 birds ranging from emus and peacocks to parakeets and cockatiels.
“People said, ‘You’re crazy.’ It was nuts, very difficult to get funding.”
Her research has taken her from South Georgia Island in the southern Atlantic to Bon Portage Island in Nova Scotia. One reason why bird researchers have tended to overlook birds’ ability to smell is because they are not trained in chemical ecology, she said.
“It hasn’t been a field that has been nurtured over the years. It’s considered kind of a cult science.”
Pelagic or tube-nosed seabirds aren’t the only ones with welldeveloped olfactory systems, she said, noting turkey vultures that spend their summers in B.C. also have a keen ability to find carrion. Nevitt would like to see more research into ducks, which also have a well-developed olfactory system.
“There hasn’t been much work done on them, which is too bad.”
Even birds such as songbirds, without well-developed olfactory systems, may use their sense of smell more than we think.
Humans have a poorly developed sense of smell compared with a dog, but smell remains important to us, she noted.