Avian flu is hitting Quebec’s emblematic wild birds more and more strongly. Everything indicates that the virus is responsible for the death of northern gannets from the very large colony of Bonaventure Island, a situation that risks causing a substantial reduction in the population of this seabird. Several other species should also suffer from the spread of the disease from Europe.
We already knew that avian flu had caused several hundred deaths among the gannets of the colony of Rocher aux Oiseaux, in the Magdalen Islands, since a large number of carcasses were collected on the beaches of the archipelago during the last weeks.
The deadly virus is now likely to be present in the massive colony of 110,000 gannets on Bonaventure Island. According to figures provided by the Society of Outdoor Establishments of Quebec (SEPAQ), which manages the Île-Bonaventure-et-du-Rocher-Percé National Park, at least 50 carcasses of the species were collected on the island off Percé for analysis. However, SEPAQ did not want to confirm that avian flu would be involved, simply stating that the results will be known next week.
For the veterinarian Stéphane Lair, director of the Quebec Center for the health of wild animals, which leads the analyzes on the carcasses, the diagnosis is however no doubt. “It remains to be confirmed, but it is only a matter of days. The samples we received come from the Gaspé Peninsula and the Percé region, so it’s definitely Bonaventure Island,” he said in an interview with the To have to.
He is not surprised by the situation, since the avian flu has already struck several species of birds in Quebec, including the turkey vulture, the bald eagle and other species of prey, but also Canada geese, snow geese and common eiders. For this last species, which lives in colonies on certain islands of the St. Lawrence, mortalities are already counted in the hundreds.
Tourists visiting Bas-Saint-Laurent, Gaspésie and the Magdalen Islands this summer should also expect to see bird carcasses on the shore, since “quite significant mortalities” are to be expected, according to the Dr The air. This is likely to be particularly true for common eiders and northern gannets, two species that live in colonies where individuals cohabit very close together. “These are population-dependent diseases, so at first the virus spreads quickly. But after a while, there are fewer birds, so there are fewer contacts and the outbreak should go away on its own, in theory. »
The veterinarian believes that the disease should not cause species extinctions in Quebec. “There are a lot of unknowns, but if we rely on what we have already observed, the populations will be able to recover. This is not necessarily the end of gannets in Quebec, but it should lead to a decrease in the population which is likely to be significant. It will take several years for her to recover. Especially since other threats await these birds, including global warming and the displacement of the fish on which they feed.
Biologist at the Ministry of Forests, Wildlife and Parks, Ariane Massé also believes that “the recovery of populations may be possible in the coming years, even if it is too early to tell”. In the meantime, public authorities invite citizens not to touch a dead or sick bird. “It is a virus which is however difficult to transmit to humans, so there is no danger for tourists to go to Gaspésie or to visit Bonaventure Island”, specifies Ms.me Mass.
Unknown mortality
The H5N1 strain of avian flu currently circulating in North America belongs to a lineage that appeared in 2014 in Eurasia (the “clade 2.3.4.4”). This was detected for the first time on our continent last fall, in Newfoundland, in great migratory sea gulls.
This relatively new lineage of the disease affects wild bird species variably. Some may be infected without symptoms—which promotes spread—while others experience considerable mortality.
“Nobody knows exactly” what the death rates are among different species of wild birds, warns Andrew Lang, an avian flu specialist at Memorial University of Newfoundland. “This version of the disease, however, seems much better suited to being transmitted among wild birds,” he notes.
In the past, bird flu outbreaks were sometimes seen in wild bird populations, but the virus died out quickly. According to what has been observed in Europe since last year, the new lineage is circulating continuously in wild populations. “There are very few ways to protect these birds,” observes Mr. Lang, who says he is “very worried” about the situation.
So far, 402 suspected or confirmed cases of avian influenza have been identified in Canada in wild birds. Elsewhere in the world, the current version of avian flu is also causing “substantial conservation concerns”, reads a recent article in the journal. Science. It cites, for example, the death of 10,000 common cranes in Israel and the disappearance of 10% of a colony of barnacle geese from the Norwegian archipelago of Svalbard at the end of last year.
New wave expected
Avian flu obviously also affects farm animals. In North America, it has spread among breeders throughout the spring thanks to migratory birds, which transmit the disease through their droppings. In hens, bird flu is a devastating disease: it can kill more than 90% of a flock in 48 hours.
“For the moment, the situation is under control,” said Marie-Hélène Jutras, a spokesperson for the Poultry Breeders of Quebec. The seven confirmed cases in the province resulted in the euthanasia of 226,000 animals, but no new cases have been detected for a month.
Poultry farmers expect a new wave of cases in a few months, when migratory birds will fly over Quebec again. “Next fall, breeders will get back on alert,” predicts Mme Jutras.