Do wolves hunt freshwater fish in spring as a food source?

In April-May 2017 we documented GPS-collared wolves (V034 and V046) from the same pack in northern Minnesota responding to a spring fish (northern pike and presumably white suckers) run, which to our knowledge is the first description of wolves outside of a coastal marine enviroment using fish as a seasonal food source. During this period, we opportunistically observed V046 hunting and consuming fish along a single creek, and documented a substantial number of wolf-killed fish in this area. We estimated V034 and V046 spent 43-63% of their daily time budget from mid-April to mid-May hunting and consuming fish at the same creek. Based on visual observation and the concentration of GPS locations, it appears the wolves targeted shallow, narrow areas along the creek to capture fish. Although short-term responses to alternate foods, such as fish, can be infrequent and challenging to document, they provide valuable insight to the flexibility of wolf hunting and foraging behavior.