The government has been allowing grey wolves to multiply despite fierce resistance from livestock owners, who say they are suffering from increased attacks on their flocks.
But this winter's increase was slower than the 23 percent jump seen the previous year, and “survival rates declined,” the OFB said, adding that the causes remained unknown.
Wolves were hunted to extinction in France by the 1930s, but gradually started reappearing in the 1990s as populations spread across the Alps from Italy.
Their numbers have grown rapidly in recent years, prompting authorities to allow annual culls to keep their numbers in check, though the predator remains a protected species.
Under a “Wolf Plan” adopted in 2018, the “viability threshold” of 500 animals, the level at which the population is likely to avoid becoming at risk of extinction over a 100-year period, was not expected to be reached until 2023.
Wolves are increasingly spotted across French territory, from the Pyrenees mountains as far north as the Atlantic coastal regions near Dieppe.
But “there are still no packs formed outside the Alps and Jura,” the heavily forested region near the Swiss border, the agency said.
The numbers are far below those found in Italy, Romania or Poland, but they have nonetheless infuriated French farmers who say the wolves are decimating their flocks.
Last year, authorities registered 3,741 wolf attacks that led to the deaths of nearly 12,500 animals, mainly sheep.
The government offers compensation for the losses and has set up a range of measures to protect flocks, including patrols by “wolf brigades” in areas where traditional anti-wolf measures, such as dogs, fenced-off areas and
additional shepherding, have failed.
That has not been enough to assuage the powerful FNSEA agriculture lobby and other groups, which say they have to wait too long for compensation payments in the face of repeated attacks on their livelihood.