WHITE WOLF: CHARACTERISTICS, HABITAT, FEEDING, BEHAVIOR - BIOLOGY - 2024

The white or arctic wolf (Canis lupus arctos) is a mammal that belongs to the Canidae family. This animal is a subspecies of the gray wolf (Canis lupus), from which it differs by being smaller, with white fur and by having a shorter snout and legs.

With regard to distribution, it is found in the Arctic, in the territories corresponding to North America and Greenland. The habitat in these regions is the tundra, which is characterized, among other things, by having the ground frozen almost all the time.

Arctic Wolf. Source: Quartl

The climate in this area can reach -60 ° C. Because of this, the polar wolf, as it is also known, has adaptations that allow it to survive in these inhospitable regions. Among these are their dense fur, which is waterproof and acts as a thermal insulator.

Their legs are short, strong and covered with hair. This allows Canis lupus arctos to run, walk or jog agilely, as the limbs balance body weight and prevent the animal from sinking in the snow.

Evolution

The gray wolf has two recognized subspecies, Canis lupus orion, native to Cape York, in northwestern Greenland, and Canis lupus arctos, from Melville Island, Canada.

The ancestor of these clades may have inhabited Greenland, 7,600 years ago. Specialists propose that two varieties of wolves evolved during the late Pleistocene, when the northern region was free of the ice that covered it during the Wisconsin glaciation.

One of these subspecies settled in Peary Land, in the extreme north of Greenland, while the other settled in Alaska. When the ice disappeared, the Peary Land wolves swept across the Queen Elizabeth Islands and Greenland. The group that was in Alaska expanded their range, becoming the wolves of the north, known as Canis lupus arctos.

characteristics

- Size

The arctic wolf tends to be smaller in size than the common wolf. Also, males are larger than females. In general, the length of its body, including the tail, ranges from 100 to 200 centimeters. In relation to height, it varies between 63 and 79 centimeters.

The body mass of this species is 32 to 70 kilograms, although some adult species have reached up to 80 kilograms.

- Adaptations to the environment

Canis lupus arctos lives in regions where the terrain is covered with snow for most of the year and temperatures are extremely low. However, the organism of this wolf has several adaptations that allow it to live and develop in that habitat.

Ears

The ears are small in size, in relation to body dimensions. Comparatively, this species has proportionally the smallest ears of all species and subspecies of wolves.

This reduces the anatomical relationship between surface area and volume. Thus, the surface area where there may be heat loss is less, compared to the larger ears of its kind.

Fur

The Arctic wolf's coat is white, although there may be light gray species. The hairs of this species are thick and highly insulating. Thus, it has a short and very soft coat, close to the skin. This fulfills the function of protecting the epidermis and thermally insulating the body of this canine.

Also, it has another coverage of long and thick hairs, which are impervious to water and snow. This may become denser as the colder season approaches.

On the other hand, the legs of the white wolf are covered with hair. It even has hairs between the pads, which turns the leg into a kind of snowshoe. These features insulate the body from ice and snow, as well as making it easier for it to move on slippery surfaces and between deep layers of snow.

Body fat

Canis lupus arctos has, under the skin, a thick layer of body fat. This is used as a source of nutrients, in case the animals that make up its diet are scarce. In addition, it performs an insulating function, which helps it survive the cold winter of the regions where it lives.

Countercurrent heat exchange in the legs

In this species, as in the domestic dog and in some birds, the legs have a system that reduces heat loss through this limb. This mechanism works when the blood that enters the legs heats the blood that comes out of it, through a countercurrent contact.

- Skull

Research on the characteristics of the skull of Canis lupus arctos. have shown that, since 1930, this structure has presented variations. These include widening, shortening of the facial region, and reduction in size. In addition, the teeth have reduced their dimensions.

Experts put forward various theories to try to explain these variations. One of these suggests that they are due to the young Arctic wolf skull not fully developing. In this sense, when the young are between 4 and 5 months old, they live their first winter, in which the little availability of food prevents the growth of this bone structure.

Hybridization

Another hypothesis suggests that the reduction and change of shape of the skull is associated with hybridization and subsequent introgression of Canis lupus arctos with husky dogs (Canis familiaris).

In this sense, the skull of a dog-wolf hybrid is intermediate in size between the skulls of huskies and wolves, although its shape varies in terms of measurements. Thus, the skulls of arctic wolves from the 1930–1950 period bear great similarity to the skull of this hybrid.

However, since 1950, the cranial morphology of the white wolf has had a reversal. Its characteristics and dimensions are more similar to its gender. This could suggest that hybridization with Canis familiaris is no longer occurring.

Taxonomy

-Animal Kingdom.

-Subreino: Bilateria.

-Filum: Cordate.

-Subfilum: Vertebrate.

-Infrafilum: Gnathostomata.

-Superclass: Tetrapoda.

-Class: Mammalia.

-Subclass: Theria.

-Order: Carnivora.

-Family: Canidae.

-Gender: Canis.

-Species: Canis lupus.

-Subspecies: C. lupus arctos.

Habitat and distribution

This subspecies inhabits the Arctic, in territories that include Greenland and North America, without spreading towards continental Europe or Asia. Thus, the populations of the white wolf are present in Canada, Alaska and Greenland. In this way, it lives in regions located above 67 ° north latitude.

The Arctic is a region located in the extreme north of planet Earth. This area is made up of the Arctic Ocean and the seas that surround it. It also includes Greenland, the world's largest island, and the northern parts of some countries, such as the United States and Canada.

Much of the Arctic Ocean remains under floating ice for most of the year. Thus, permanent ice only covers a small part of the outskirts of Greenland. In relation to the predominant habitat, it is the tundra. This is characterized by plains without grass or trees, with permanently frozen soils.

As for the climate, it varies according to the season and the geographical location. During winter, in various regions they can reach temperatures of -60 ° C. On the contrary, in July the weather is warmer, reaching temperatures around 20 ° C.

Sub regions

Within the Arctic region, environmental conditions vary, causing the territory to be divided into Low Arctic and High Arctic.

In the High Arctic, environmental conditions are severe and it is characterized by the presence of an extreme form of Arctic tundra, known as the polar desert. In this, the humidity levels are very low, so the vegetation is scarce.

In relation to the Lower Arctic, approximately 80% of the area is covered by some varieties of grasses. The ice sheet that forms the soil in this region thaws annually, during the summer.

Biodiversity

Despite the extreme climatic conditions in the Arctic, a great diversity of plant species proliferate. These can range from mosses, including the Silene moss (Silene acaulis), to the Arctic willow (Salix arctica). This one only grows around two meters tall, being one of the tallest plants in the tundra.

As for animals, there are approximately 450 species of fish, among which is the Arctic cod. Birds are also present in this cold region, as is the case with the black goose and the ivory gull.

In relation to mammals, some representatives of this clade are the Arctic hare, the musk ox, the reindeer and the polar bear.

State of conservation

In recent decades, white wolves have not been threatened by poaching, as is the case with other subspecies of gray wolves. This situation is mainly due to the fact that the regions where Canis lupus arctos inhabits are depopulated of human beings.

Currently, the arctic wolf is not included in the IUCN red list. However, the populations of this subspecies are threatened by climate change.

Climatic changes are unleashing a series of negative effects on the different ecosystems of the Arctic. Thus, plant species have seen their development altered, which has an impact on the diet of herbivores. This affects the Arctic wolf, since this food group is a fundamental part of its diet.

Situation of the white wolf in 1930

In the 1930s, Canis lupus arctos was exterminated from eastern Greenland. This occurred as a result of the action of the hunters. Later, for more than 40 years, the specialists considered this subspecies absent from that habitat.

In 1979, experts reported the recolonization of the eastern area of ​​Greenland, by the Arctic wolves that inhabited the north of that country. This led to the successful establishment of a new population, since in addition to the pair of wolves that initially settled in the area, later two more did.

Feeding

The arctic wolf is a carnivorous animal. Their diet includes seals, birds, elk, arctic foxes, and caribou. Also, it can eat carrion, coming from hunting other predators.

However, studies reveal that the favorite prey are arctic hares and musk oxen. The proportion of consumption between both species depends on the geographic range where they live and the season.

In this sense, the Arctic hare is a fundamental species for the white wolves that live in the High Arctic. In this way, they can survive and remain in that region of extreme cold, even in the absence of ungulate species.

With regard to the feeding of the young, experts point out that the young musk ox are the primary source of nutrients. This is due to the high energy needs of the puppies. However, when the arctic hare is the most abundant prey, it constitutes the main component of the diet of the white wolf pups.

Although Canis lupus arctos rarely has contact with the polar bear, there are records of packs of wolves attacking the cubs of this mammal.

The hunt

The size of the territory that this species occupies will depend on the availability of food. Thus, the home range of a herd can be more than 2,500 km2. The Arctic wolf ingests up to 9 kilograms of meat in one meal. It usually consumes the entire animal, it does not waste any part of the body, not even the bones.

As for the hunting method, it will fundamentally depend on the size of the prey. In the case of small animals, such as hares and arctic foxes, they can be chased and captured alone. However, large ungulates are hunted in herds.

The technique used in these cases requires the coordinated action of all the members that make up the group. They generally do not chase the prey at high speed, although they can sometimes reach 75 km / h. The group follows the animal at a moderate pace, until it is physically exhausted.

Usually, the first to tire of the chase are the young, the most adult or the sick. Once the animal is left behind, the arctic wolves intimidate it with their fangs, while surrounding it. In this way they prevent him from fleeing the corral.

When hunting an animal, it does not matter if it is larger or has strong horns. The attack is altogether, while a wolf bites a paw, another lunges towards the neck and finally the entire pack attacks the prey completely, killing it.

Reproduction

Canis lupus arctos reaches adult size when it is six to eight months old. As for sexual maturity, it usually occurs around 22 months.

As in other species of wolves, only alpha males and alpha or beta females can mate. In addition, the fact that the young do not have access to reproduce causes them to leave the herd at an early age. The intention is to form their own herd, where they can reproduce.

Because the Arctic soil is frozen most of the time, the white wolf is unable to excavate its lair. This is why it often uses rocky outcrops, shallow depressions in the ground, or caves as burrows.

The babies

The gestation period lasts about 63 days. At the time of delivery, the pregnant female goes to the den, where 2 to 3 cubs are born.

Newborns have darker fur and their eyes are blue. This color will change to orange or golden yellow, when they are between 8 and 16 weeks old. Their eyes and ears are covered, so they depend on instinctual behavior and smell to survive the first weeks of life.

When the young person is 12 to 14 days old they can already hear the various sounds of the environment that surrounds them. After 3 to 6 weeks, the cubs emerge from their den, beginning to venture into the surrounding environment. However, they don't stray far from the shelter

At three months, they are already part of the herd, with which he travels and hunts. In this species, all members of the group collaborate in the protection of the cubs.

Behavior

White wolves are grouped in packs, which can be made up of up to 20 wolves. In general, the size of this group will depend on the availability of food. In relation to the reproductive pair it is formed by the stronger male and female

An arctic wolf can often be seen alone. This may be associated with the search for food or that he is trying to form his own herd.

Canis lupus arctos uses body language to convey rules to group members. As a main rule, make it clear that the alpha male is the leader, followed by the alpha female. To demonstrate dominance, the male holds his tail high and his body erect.

The Arctic wolf is very territorial, marking its space with urine and feces. However, the range of home is usually very wide, so it generally allows other herds to overlap their territory. In the following video you can see how a group of Arctic wolves hunt a hare:

References

1. Wikipedia (2019). Artic Wolf. Recovered from en.wikipedia.org.
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3. Dalerum, S. Freire, A. Angerbjörn, N. Lecomte, Å. Lindgren, T. Meijer, P. Pečnerová, L. Dalén (2017). Exploring the diet of arctic wolves (Canis lupus arctos) at their northern range limit. Recovered from nrcresearchpress.com.
4. Clutton ‐ Brock AC Kitchener JM Lynch (1994). Changes in the skull morphology of the Arctic wolf, Canis lupus arctos, during the twentieth century. Recovered from zslpublications.onlinelibrary.wiley.com.
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6. ITIS (2918). Canis lupus arctos, Recovered from itis.gov.
7. José Martín, Isabel Barja, Pilar López (2010). Chemical scent constituents in feces of wild Iberian wolves (Canis lupus signatus). Recovered from researchgate.net.
8. Dalerum, Fredrik, Freire, Susana, Angerbjörn, Anders, Lecomte, Nicolas, Lindgren, Åsa, Meijer, Tomas, Pečnerová, Patrícia, Dalén, Love. (2018). Exploring the diet of Arctic wolves (Canis lupus arctos) at their northern range limit. Canadian Journal of Zoology. Recovered from researchgate.net.