What do wolves eat? Diet & nutrition of the wolf
With their powerful nature, blood-curdling howls, and fierce looks, wolves are as much the subject of admiration as trepidation. These legendary creatures have been much maligned in folklore, typically being typecast as evil and cunning. It is perhaps this dubious characterization that led to extermination programs that saw their numbers dwindling to near extinction point in the early 1900s.
Thankfully, federal conservation projects ensured that these awe-inspiring creatures did not go the way of the Dodo. Their Machiavellian-villain-like status may still stand today, but the truth is that wolves are a keystone species whose hunting and eating patterns play a crucial role in maintaining a healthy ecosystem. To better understand why and how that is, let us take a deeper look at their dietary habits and practices.
1. The Wolf Diet
Wolves are the largest members of the dog family. Strictly speaking, they are classified as carnivores. Since the historic range of the gray wolf covered over two-thirds of the United States, it would be inaccurate to narrow their diet to only one animal. Despite popular belief, wolves don't only hunt small animals such as snowshoe hares or beavers. Their main food source and meat of choice are ungulates (hoofed mammals such as deer, elk, moose, or bison). However, this is not to say that they give vegetables and fruits a wide berth.
Unlike obligate carnivores, such as the feline species, wolves have the digestive capabilities needed to synthesize plant-based food. These fierce creatures are known to eat berries, apples, carrots, and melons. About 20% to 30% of their overall diet consists of the vegetarian kind. These fruits and vegetables supply wolves with valuable nutrients that are missing in meat, such as Vitamin C, carbohydrates, and flavonoids. Like other canines, they also eat grass if they have ingested something that disagrees with their digestive system.
To survive, adult wolves need a minimum of around 2 to 3 pounds of meat every day. However, for growing and reproducing wolves, this minimum amount increases twofold due to their advanced nutritional requirements. That said, wolves very rarely eat every day. They have a feast-or-famine style of consumption. When prey is hard to come by, they can go days, even weeks, without eating.
Conversely, they can consume a whopping 20 to 22 pounds of meat in one sitting! Quite different from a dog's diet, right? Their stomachs can hold a massive amount of food, allowing them to gorge when necessary. If push comes to shove, wolves will scavenge and eat carrion, though they prefer not to. This dietary flexibility is one of the reasons they have survived against all the odds, coming back from the brink of extinction no less. By combining plants and meat wolves get the starches and omega-6 fatty acids (in the fat of the meat) they need. The first act as a source of energy, the latter prevents cardiovascular diseases and cancers.
But within the wolfpack, not all members are equal when it comes to food: the social hierarchy of the pack dictates the order in which wolves eat, as well as the quantity they can have.
2. Seasonal Eating Patterns
Another reason why wolves are so resilient is that they are opportunistic predators. This trait means that they will eat any creature that crosses their path. No animal is too large or too small for it. That is why it is hard to identify a wolf's main prey. This can vary from a mighty 1000-pound bison (that's over 400 kilograms of food) to a humble 3-pound rabbit and anything in between. This versatile and all-inclusive diet is not because they are the gastronomes of the wild. Rather, it is the result of factors such as weather conditions and seasonal availability. Given a choice, wolves would gorge on ungulates 365 days a year. Seasonal conditions, however, do not afford them this luxury.
Here is how a wolf’s diet changes by season:
The Winter Diet
While many animals struggle to negotiate the travails of winter, wolves thrive during this season. There are several reasons this is so. For one, as the temperature drops, they develop a double layer of thick fur. This protective double layer helps them survive frigid temperatures as low as -35⁰ F. For another; they have large, wide feet that act akin to snowshoes, allowing them to traverse uninhibited even in deep snow. Besides, they have special blood vessels in their feet that operate like toe warmers, preventing their paws from freezing.
Conversely, ungulates have smaller, hooved feet that make navigating deep or crusty snow a cumbersome process. Wolves, being the intelligent creatures that they are, will often work to trap their prey in a pocket of deep snow, thereby increasing their chances of catching it exponentially. Not only that, due to the sparse grazing opportunities, the prey is also usually at their weakest during the more severe winter months. This combination of weak prey and superior winter biology work out in the wolves’ favor more often than not. As a result, an overwhelming percentage of a wolf’s winter diet consists of ungulates such as deer, caribou (reindeer), and moose.
The Spring Diet
Late winter and early spring bring with it the wolves’ mating and reproduction seasons. Alpha females typically give birth to pups in April inside a den. This family den becomes an anchor that keeps the wolf pack tied to an area. Consequently, they are restricted to eating whatever prey is available within their territory. The good news is that with the melting snow comes the return of smaller mammals such as beavers, rabbits, and mice.
Spring also brings with it fruits and vegetables. During this time, wolves will eat everything from squirrels and gophers to insects and berries and any ungulates they can find. They are even known to hunt for freshwater fish. Besides eating whatever they can get their hands (or paws) on, the idea behind the gorging is to put on enough weight to make it through the reproduction stage with healthy pups.
The Summer Diet
As summer rolls around, the mother and young pups emerge from the den. The wolf pack is hence free to move away from their focal point and can now explore and hunt the full length and breadth of their territory. However, as any parent will tell you, traveling with young ‘uns is never easy. They tire easily, need frequent breaks, and are prone to wandering off on a whim. This behavior is no different for the wolf family. The adults in the pack now shoulder more responsibility. Not only do they have more mouths to feed, but they must also protect the young pups from harm.
Compounding this, they no longer hold any biological advantage over their prey as they did in the wintertime. Despite a wolf’s much-touted status as a premier hunter, most of their prey can easily outrun them. You would then think that a wolf's primary prey is a somewhat slow animal but in actuality, wolves have a success rate of only 3% to about 14% when they give chase. Fortunately for them, summertime is also the time when ungulates breed and give birth to their young. These ungulate fledglings make for easy pickings for the wolves and make up a bulk of their summer diet.
The Fall Diet
Come fall, wolves look to fatten themselves up once again for the upcoming winter season. Wanting to stay close to their prey, a lot of wolf packs migrate along with their prey, picking off the weak and elderly among them along the way. Those close to streams are also known to hunt for salmon as and when they come upstream. Alaskan wolves are known to completely switch over to a salmon-based diet in the fall as do wolves in other coastal regions.
There are several reasons that wolves switch from their preferred prey of hoofed animals to catching salmon. First, catching fish is a lot less risky than hunting ungulates and takes up only a fraction of the energy needed too. Second, being fatty, salmon is a good way for the pups to put on some weight before winter hits. They also get to satiate their hunting instincts without getting hurt.
3. A Wolf Pup’s Diet
In the Beginning
Wolf pups, which are born after a gestation period of just over two months, come into this world completely and utterly helpless. They weigh a measly 1 pound at birth, are blind and deaf, and have little sense of smell. As such, they are wholly dependent on their mother. For the first month of their lives, the pups live exclusively on their mother’s milk, feeding at least 4 to 5 times a day.
During this time, their eyes and ears open, and they stumble and bumble their way around the den, getting stronger and more coordinated with every passing day. Wolf pups gain weight rapidly at a rate of 2.5 to 3.5 pounds every week. At around 3 to 4 weeks of age, they develop their first milk teeth and are now ready to graduate onto eating meat.
A Gradual Graduation To Meat
At five weeks of age, though, their jaws and digestive system have not yet developed enough to chew and digest raw meat. So, a pup’s first taste of meat comes in the form of regurgitated meat brought back by the adults in the pack. So wolves don't bring back their prey to the den: the adult pack members swallow meat and when they come back from a hunt, the pups instinctively ‘ask’ for food. They do this by adopting a completely different body language, whining, pawing, and licking the adult’s mouth. This behavior causes the older wolves to regurgitate or throw up portions of the food already present in their stomach. As disgusting as this may sound to us, it is a foolproof way for the wolves to bring back food to the pups safely. Also, the half-eaten food is easier for the wolf pups to tear into and digest.
For the next 3 to 4 weeks, wolf pups alternate between eating regurgitated meat and drinking their mother’s milk. The mother wolf fully weans her pups only when they are 8 to 10 weeks old. Once weaned, the pups can move on to eating raw meat by themselves. This period is when the pack moves away from the den, and the pups start going on short hunting trips with the rest of their family. Even so, they begin to actively participate in hunts only once they are around eight months old.
4. How Wolves Hunt
Though they usually sit at the top of the food chain in any given area, wolves have some biological limitations restricting their hunting capabilities. Deer have a top speed of about 50 miles per hour. In comparison, the wolves’ shorter limbs mean they peak at about 40 miles per hour. Ungulates are also almost always bigger than wolves. But what the wolves lack in pace and size, they make for up with stamina and teamwork. For these highly social animals, teamwork truly makes the dream work.
The wolf pack works together collaboratively to, first, identify their prey. Given that there is a high chance of getting injured or simply being outrun if they pick a healthy ungulate, wolves tend to go for the weaker, easier to ambush animals. They will then patiently isolate and hound their target if they need to, sometimes following them for miles, until the prey eventually tires out. This time is when they move in for the kill. What is extraordinary is that this coordinated effort takes place with little to no verbal communication or signals. Every member of the pack knows exactly what their role in the hunt is and plays it to absolute perfection.
5. Ecological impact of A Wolf’s Diet
When it comes to creating a balanced ecosystem, wolves play a starring role. Wolf predation may represent compensatory or additive mortality. Their habit of picking off the weaker members of the ungulate population acts as a form of natural selection. It ensures that only the healthy among them survive. These healthy ungulates then go on to procreate and pass on their genes to the next generation.
Besides, the very presence of a wolf pack causes the ungulate population to move away in search of safer pastures, thereby allowing the vegetation in that area a chance to flourish. These wolf predation effects were famously demonstrated when 14 grey wolves were reintroduced into Yellowstone National Park in 1995 as well as in Northern Michigan's Isle Royale National Park but also with the arrival of Mexican wolves (Canis lupus baileyi) in eastern Arizona and southwest New Mexico.
Sensing the fierce predators’ presence, the deer population moved to the periphery of the park, allowing the vegetation to grow lush. This, in turn, saw the population of everything from birds and beavers to berry-loving bears increase. The wolves also kept the population of mesopredators such as coyotes in check, which correspondingly increased the population of smaller mammals such as foxes, rabbits, hares, and mice.
Even though their numbers were small, the reintroduced wolves had a cascading effect on the Yellowstone ecosystem, causing it to thrive and become more diverse. This phenomenon where a change at the top of the food chain causes a ripple effect felt all the way down to the bottom is called a trophic cascade.
One of the most compelling tales of American wildlife is obviously the gray wolf's story. Whether vilified or revered, there is no denying that these fierce and impressive creatures are integral to their ecosystem and should be viewed and preserved as such.