Voyageurs Wolf Project is an initiative of scientists who since 2012 collared 74 wolves coming from random wolf packs, collected data from thousands GPS points placed where they wandered, and scrutinized what they eat (scat analyses) and what tactics they prefer for hunting.
According to VWP reports, Minnesota wolves' diet is flexible, nearly omnivorously (vide berries) switching between food resources depending on season - from collectively chased adult white-tailed deer (in winter) to smaller prey when a wolf pack disperses (in spring, during mating season). Exemplary carnivorous diet based on caribu (primary, collectively hunted) and beaver (secondary, hunted alone), was previously scientifically studied in Yellowstone.
Typical gray wolf species prey drive is a specific sequenced behavior, evolutionary adapted, inherited by generations, initiated and proceeded as a hunt strategy, in family pack if a prey is large ungulate as a principal preyed animal (gray wolf representatives are social animals).
SEARCHING -> TRACKING -> STALKING -> CHASING -> GRABBING -> KILLING -> DISSECTING -> EATING
However, video material coming from Voyageurs Wolf Project camera traps (May 2018), documents certain changes in Minnesota wolf predatory behavior strategies.
Since 2015, the VWP identified approximately 400 situations when wolf ambushed on beaver - attacking from downwind, so beavers couldn't sniff an approaching predator.
Being strict, some wolves adapted to strictly fish-based diet.
Counting 250 individuals, certain wolf population called Coastal Wolves, inhabits Vancouver Island (north of Seattle), adapted to live in the ecological niche - the temperate rainforest part located on the shore of the ocean, swimming spontaniously between small islands. About 20% smaller than their Timber or Arctic relatives, they catch salmon in the streaming water, herring eggs, clams and crabs, standalone instead of collective hunting ungulates. Their diet is 90% sea-associated.
Fish-hunting, beaver-hunting, they seem to be kind of learned skill, a temporary hunt strategy, likely influenced by terms and conditions which the inhabited ecosystem would offer, rather than permanently adapted ones (not mentioning about innate one). Ambush-and-pursuit behavior describes feline - not canine - behavior by definition. Besides, it points on a time-consuming waiting alone patiently in freeze, which excludes social rituals and dynamic migrating, usually in family packs - another natural Canis lupus terrestrial behavior, essential to survive.
 They evidenced the gray wolf territorial behavior (Dec.2018) making the map of results collected from 7 wolves (a different wolf pack each one). Each wolf's collar took locations every 20 min (with the exception of the northernmost pack which took locations every 4 hr starting in October) for the duration of the summer - quoting the VWP official info./detailed map below/
 In comparison, Polish wolf diet stays strictly carnivorous and constant, regardless of season.