Arizona wildlife officials say nine endangered Mexican gray wolves were reported dead in the third quarter of this year.
According to the Arizona Game and Fish Department, two of the animals are suspected of having been illegally killed.
In all, 21 wild Mexican wolves have died this year compared to a dozen in 2022 and 25 the previous year.
At last count, there were at least 242 of the animals in nearly 60 packs living in the wild, which represented a 23% increase in their Southwestern population.
Mexican wolves are the rarest subspecies of gray wolf in North America and were nearly eliminated from the wild by the 1970s.
A federal reintroduction program in Arizona and New Mexico began 25 years ago.
In the years since, illegal killings and a lack of genetic diversity within the population has hampered recovery of the species.