wolf Biology & Behavior
~ Communication ~ Reproduction & Pup Development ~ ~ wolf packs ~ Hunting ~
Communication
Believe it or not, much like humans, a large portion of communication between wolves is non-verbal. For example, wolves will look each other in the eye (like humans) when communicating a greeting, dominance behaviors, and other social gestures. Additionally, wolves regularly use facial postures to communicate with each other. More obvious methods of non-verbal communication include tail position, which is used to communicate a wolf's position within pack hierarchy compared to other members. Wolves that carry their tails straight up are displaying dominance, while submissive wolf behavior is shown by tails that are pointed downward or tucked underneath the body.
In addition to non-verbal communication, wolves also use their incredible sense of smell for communication. Wolves will use urine and scat to mark their territory for foreign wolves. Interestingly, wolves use their sense of smell to communicate through chemical messages. These chemical messages between wolves are not only able to communicate hormone cycles for breeding, but also emotions (excitement, fear, aggression) in unknown wolves, and even level of relatedness!
Wolves are probably most famous for their howl - one of several forms of verbal communication displayed by wolves. Although wolves are believed to be howling at the moon, this is not technically true. Wolves are nocturnal, so they are most active and thus, howling most at night. When you hear a wolf howl in the night - they are not howling at the moon–they are communicating. Howling is a long-distance form of communication between wolves, and it is suggested that wolves are able to hear another howl up to 10 miles away in open terrain. Wolves will howl to locate pack members, to advertise their claim to a territory, to warn other pack mates of danger, and to communicate a variety of other feelings and messages. Much like each human has their own distinct voice, each wolf has a unique howl. When every pack member howls together, the harmony of their individual howls makes it sound as though the pack is larger than it is.
Other forms of verbal communication include barking, whimpering, and growling. Barking is used as a warning signal and is more of a combination of bark-howl or growl-bark. Whimpering is usually used to communicate submission to a more dominant wolf. Growing is a warning as well, but intended to be more of an aggressive warning to indicate dominance or potential aggression.
Wolves have multiple forms of communication: non-verbal or body language, verbal, and olfactory.
reproduction & pup development
In general, only the dominant mating pair will breed. However, in environments abundant with prey, a pack may have multiple litters from different breeding pairs. Wolves breed once a year, coming into estrus as early as late January and ending sometime in March. The gestation period for wolves is about 63 days, so pups are born in April or early May. The average litter size for gray wolves is 4 to 6 pups, and different environmental factors can determine the litter size.
Wolf pups are born blind, deaf and require their mother for warm. At birth pups weigh about a pound. By two weeks old, their eyes are open, and by three weeks, they are moving about and exploring. Wolf pups grow rapidly; by 6 months old, they are almost as tall as the adults.
wolf packs
A wolf pack is a cohesive family unit that is usually made up of a breeding pair or parents and their offspring of different ages. It is not uncommon for unrelated wolves to join a family or pack. It is important to note that in some cases, the parents may have passed, so the "breeding pair" will be an adult sibling with an unrelated mate. Wolf pack social structure is highly complex and can differ from the standard definitions.
Wolves are eusocial animals. This means wolf packs are social groups consisting of overlapping generations that display a division of labor into reproductive and non-reproductive groups, which both participate in rearing and caring for pups. Eusociality usually creates a behavioral hierarchy within the group.
The size of a wolf pack is highly variable due to prey availability, birth of pups, dispersal, and mortality. The Druid Peak Pack in Yellowstone National Park was once reported to have over 30 members. However, large packs are unusual and not necessarily an advantage. More pack members means more food must be obtained. Wolf packs are generally largest in the fall, when pups are strong enough to hunt with the adults. During winter, some wolves may disperse or die, so the pack size is usually smaller by spring.
Wolf packs will claim and defend a territory anywhere between 50 and hundreds of square miles.
Hunting
Wolves are carnivores who primarily prey on ungulates, or large hoofed mammals (for example: deer, moose, bison, elk, and caribou). There are also some wolves who fish for their prey! Wolves will gorge on their prey, eating up to 20 lbs at once, then will go days or sometimes weeks without a meal. Patterns of wolf predation on ungulates varies season by season. Wolves are built to move easily through snow, so during the winter wolf when prey is lacking abundant food sources, wolf predation is highest.
Wolves have webbed paws, which help them move over snow with ease. Their front paws are also exceptionally large, allowing for a greater weight distribution and more support against sinking into snow. Ungulates also have adapted defensive traits against wolf predation such as good hearing and olfactory senses, agility, and hooves. Injuries from hunting, such as a hoof to the head, account for a large portion of wolf deaths.
There is evidence that wolves actually create healthier prey populations as they will prey upon vulnerable members of their prey's herd, such as sick or old individuals. Over generations, this process will create the most adapted prey population for survival, an evolutionary process seen in other predator-prey relationships.
Wolves are endurance predators; instead of ambushing their prey by surprise, wolves will chase their prey over longer distances, looking for the perfect opportunity. Since injury from hunting can be fatal to a wolf, wolf packs work to tire their prey out before moving in. Pack members will work together on a hunt, with each individual member taking a specific roll in the hunt. Only a few wolves are actually involved in the physical take down of prey. Pups and yearlings usually observe and learn from the sidelines. Pack members roll in the hunt is dependent on experience and ability. Usually, the smaller but quick females work to "herd" target prey and prevent escape, while larger males take down their massive prey. Although the "alpha" male is usually in a central role during the hunt, it would be incorrect to say that he leads it. "Alpha" wolves might select individual targets or end hunt going poorly, but by no means are they giving out orders to submissive members. Each pack member just knows what they need to do. The wolf pack hunts as one - it is a masterfully coordinated group effort!
