The Cowboy State Daily reports that the elderly one-eyed wolf named Wolf 907F gave birth to her latest litter last month. The gray wolf (Canis lupus) has an average lifespan of three to four years, making it rare for them to reach the age of 11, let alone give birth at that age.
Wolf 907F has been giving birth annually for over 10 consecutive years since reaching maturity, which Kira Cassidy, a research collaborator at the Yellowstone Wolf Project, states could be a record for wolves in Yellowstone National Park, USA.
Wolf 907F passing by a camera on a trail in Yellowstone National Park. (Photo: Yellowstone Wolf and Cougar Project).
Cassidy stated, “Every day, I think it could die just from old age, but I have thought that for several years and this old female wolf continues on.”
Cassidy noted that only about 1 in 250 wolves in Yellowstone survive to their 11th birthday, with only 6 cases recorded since wolves were reintroduced to the park in 1995. The oldest among these magnificent wolves lived to be 12.5 years old.
Wolf 907F is the oldest wolf that has lived her entire life in the Northern Range of Yellowstone, an area with more prey but also greater competition from other wolves. Wolves rarely die of old age in the wild, and in Yellowstone National Park, the greatest threat comes from other wolves.
Cassidy remarked: “The number one cause of death for wolves is when two packs fight. This accounts for about half of the mortality rate.”
Wolf 907F is a founding female of the Junction Butte pack, which consists of 10 to 35 members at any given time. Cassidy pointed out that this is a large pack – the average wolf pack size is around 12 individuals. Wolf 907F’s experience also gives her pack an advantage. The Junction Butte pack rarely leaves the boundaries of Yellowstone, and Wolf 907F is very knowledgeable about crossing roads and avoiding humans.
What makes Wolf 907F even more impressive is that she accomplishes all of this with only one functioning eye. Researchers are uncertain what happened, but this female wolf lost her left eye before she turned 4.
A 2012 study on Yellowstone wolves published in the Journal of Animal Ecology showed that the number of litters decreases with age. Cassidy stated: “It’s remarkable that Wolf 907 is still giving birth, let alone regularly every year despite her old age.”
Some of Wolf 907F’s offspring are now leading their own packs, but most of this wolf’s pups do not survive to adulthood due to the dangerous nature of being a wolf.
