Wolf researchers working in Voyageurs National Park released video on Thursday that shows wolves hunting for spawning fish in a stream in the park. The scientists believe it’s the first footage ever captured of the famous predators pursuing fish in a freshwater system (they have previously been observed catching salmon in western rivers).
The researchers first observed the behavior in the spring of 2017, and published the findings in a peer-reviewed article. The two wolves observed fishing had been fitted with collars that transmits their location coordinates.
“Freshwater fish were a valuable, seasonal food source for V034 and V046 based on the substantial time both wolves spent at and near this creek,” the article states.
It seems that fish may play an important role in supplementing wolf diets as the snow is melting, which makes large ungulates like deer and moose more difficult to hunt. The wolves appeared to eat mostly northern pike and white suckers.
“On an individual level, fish likely provided much needed food for V046, a 22 kg at capture yearling wolf that was likely inexperienced at hunting. Indeed, prior to the fishing period, V046 had not killed anything for 17 days and had been relying on scavenging. Northern pike and other freshwater fish that routinely spawn in small creeks in early spring can often be at peak body size and fat content in spring, and thus especially nutritious.”
Last week, the same researchers reported surprising data that showed wolves also spend weeks of the summer eating ripe blueberries. Other findings have focused on the role of beavers in their diet. The Duluth News Tribune reported that these diverse food sources may help explain why Voyageurs’ moose population has remained relatively stable while it has declined in other parts of northern Minnesota.
Fascinating footage
Not only do some wolves appear to pursue the fish, they dedicate a lot of their days to it during the spawning season. By studying the GPS data, the researchers estimated they spent 43 to 63 percent of their days to fishing between mid-April and mid-May.
This season, the team set up remote cameras to attempt to record the activity, and succeeded. The cameras recorded the animals hunting fish in the dark of night. It gave wolf experts a thrill to see for the first time.
“The wolves are standing next to the creek in the dark, just listening or looking,” lead researcher Thomas Gable said. “You can see the wolves abruptly head to the water several times after hearing a splash—they learned what a fish splashing in the creek sounds like and they know that it means food. Incredible.”
Within eight hours of posting the video on Facebook, it had been watched more than 53,000 times.
Reference
Gable, Thomas D., Steve K. Windels, and Austin T. Homkes. “Do wolves hunt freshwater fish in spring as a food source?.” Mammalian Biology 91 (2018): 30-33.