“This is the first study to show that genetic problems not only affect a specific population and increase the risk of extinction of that population, but also have broader implications for all species,” Sarah Hoy, lead author of the study published Wednesday, told AFP in the journal Science Advances.

This ecology researcher’s team at Michigan Technological University studied the ecosystem of Isle Royale, which lies on the American side of Lake Superior, a vast stretch of freshwater between Canada and the United States. States, upon arrival on site one is a lone wolf unknown to the local pack.

In 1997, this newcomer, affectionately dubbed “the old gray wolf” by researchers in the context of the “M93” study, crossed an ice bridge between Canada and the island.

The first known wolves came to this area in the 1940s, mostly hunting moose. This made it possible to conduct the longest study ever conducted on the predator-prey system.

In the 1980s, the introduction of a virus called “canine parvovirus” into this ecosystem helped the local wolf population decline from fifty to a dozen, the study points out.

New breeding male

But the arrival of the “old gray wolf” changes the situation for local packs and the entire ecosystem. As he is not affiliated with this pack and is particularly large, which is a key advantage over the moose, he has established himself as the new ‘breeding male’ in one of the three packs on the island and is even the parent of 34 cubs.

This not only diversifies the gene pool of the island’s wolves, but also improves their ability to kill moose.

Since elk, herbivores, eat up to 14 kilos of vegetation a day, reducing their numbers compared to wolves also leads to a remodeling of the ecosystem to restore its balance, the American researchers conclude.

With fewer moose, balsam firs grew at their fastest rate in decades, which was vital to the forest and, by extension, a wide variety of plants and species.

But that’s not the end of the story, and the boom in the wolf population eventually created a new imbalance in the ecosystem due to inbreeding.

After the death of “M93”, which had passed its gene pool to about 60% of the wolves, the population began to decline again until only two wolves remained: a father and his daughter, who was also a half-sibling.

However, a reintroduction program for the species that began five years ago has restored a better balance to this isolated ecosystem, which is now home to about thirty wolves and nearly a thousand moose, also known as “elk” in North America.

For Sarah Hoy, the case of the “old gray wolf” could undoubtedly apply to other populations of inbred predators threatened with extinction, such as cheetahs, by showing that the introduction of one or more individuals into a gene pool is not just a population renewed, but also an ecosystem.

William Ripple, a professor of ecology at Oregon State University, called his Michigan colleague’s work, in which he was not involved, “important” in showing that genetic processes can limit the ecological impact of a given species, he said to AFP.