Words by Gretchen Kay Stuart
The wolverine is historically perceived as a vicious, solitary predator evoking alarm and disdain among the public. But this carnivore has been profoundly misjudged. Recently, researchers have been noting that wolverines are not as solitary as once presumed, and the family we research has been breaking this stereotype, transforming these feared and misunderstood mustelids into the endearing, relatable mammals that they truly are.
Cascades Carnivore Project has been documenting wolverine reproduction since 2018 when kits were born near Mount Rainier for the first time in over a century. Female wolverines typically give birth every other year, provided their midwinter body condition is strong. But Joni, the rock star mama of Mount Rainier, reared four consecutive litters including triplets in 2023, and after taking one year off from motherhood was pictured with a single kit at one of our monitoring stations in 2025. As thrilling as it has been to document wolverines repopulating Washington’s Cascades, the social behavior this family has demonstrated is just as groundbreaking.
In 2023, Joni, her mate, Van, and their approximately 5-month-old triplets were caught on video roaming around the subalpine as a family unit. Male wolverines were once thought to abandon their families, only meeting up with females annually to mate. But in recent years, researchers have found that male wolverines occasionally deliver food to den sites, and we have evidence of Van playing a fatherly role, possibly offering some indirect protection or allowing his kits to utilize shared food caches as they follow him around their mother’s territory.
These familial relationships extend beyond weaning. While kits become independent by the fall at around six to eight months of age, they often remain within their mother’s home range for an extended period. Young females have been documented establishing territories adjacent to their mother’s or taking over a portion of her range completely, as we observed when Joni appeared to give part of her territory to her 2022 daughter, Jackie.
Equally fascinating, older wolverines appear to spend time with their younger siblings. Two-year-old Jackie was seen with her one-year-old brother on camera only ten minutes after their father stopped by.
In 2024, 1-year-old brothers from Van and Joni's 2023 litter were still hanging out together through rest and play. They spent three months interacting in front of our monitoring station cameras (also seen in the opening image) before leaving the area.
Van and Jackie playing at a runpole.
Last April, Van was spotted for the 2nd time enjoying what can only be described as a play date with his three-year-old daughter, Jackie.
Sociality in wolverines is mysterious with fragmented documentation. Van, Joni and their offspring give us a rare opportunity to delve into the depths of familial bonds. Because social behavior is a critical part of carnivore survival, biologists urgently want to learn more. These revelations prove the value of long-term research, and we look forward to documenting this family for many more years to come.