polar bear
The largest bear in the world
Mammals of the carnivorous bear family
Polar bears (Latin: Ursus maritimus), also known as white bears, are the largest carnivores that survive today, belonging to the genus Brown bears of the carnivorous bear family. Polar bears are mainly distributed throughout the Arctic and are active on Arctic ice floes throughout the year. The body size is larger than other bears, polar bear males are about 2.2 to 2.5 meters long, males weigh about 410 kg, females weigh about 1.9 to 2.1 meters and weigh about 200 to 400 kg, polar bear necks are also longer than other bears, the head is long and pointed, and the ears are small and round. The fur is long and thick, the fur is milky white, and the soles of the feet are wide and thick, which is conducive to walking on the ice and has a cold protection effect.
In 2017, polar bears were rated vulnerable (VU) on the IUCN Red List and listed in Appendix II by the International Convention on Endangered Species of Wild Animals (CITES).
Morphological characteristics
Polar bears have large, sturdy bodies, similar to brown bears. Compared with other bears, adult males weigh between 300 and 800 kg, and females weigh less, weighing 150 to 300 kg, and the length from the tip of the nose to the tip of the tail can reach 2.5 m. The tail is 8 to 13 cm long, the proportion of the head is small, the neck is longer, the ears of the polar bear are small and round, its nose, claw pads, lips and the black skin around the eyes have shown its original skin appearance, black skin helps to keep warm and cold, which is a good way to absorb and preserve heat. Polar bears' dentitions are perfect for eating meat. The canine teeth are slender, conical, and slightly hook-shaped, used to catch prey, and the male canine teeth are very large. Polar bears have 5 toes per paw, and the claws are retractable and 5 to 7 cm long. Polar bears have wide front paws and fur on the soles of their hind and fore feet. The body's hair is generally white, but in the summer it will turn yellowish due to oxidation, depending on the season and light conditions. The white fur is transparent under light refraction, and females have four functional breasts.
Morphological characteristics of polar bears
Species comparison
Contrast dimensions
polar bear
bear
appearance
weight
400 to 600 kg
About 200 kg
Distribution area
Near the Arctic Ocean
Europe, Asia and North and South America
Feeding habits
Carnivorous
Omnivorous
section
Ursidae
Ursidae
Distributed habitat
Distribution range
Polar bears are distributed in rings and spread throughout the Arctic. The main area of activity is on the ocean, and the range of activity depends mainly on the distribution of ice floes. Polar bears are mainly distributed in the countries surrounding the Arctic, in the United States (Wrangel Island, western Alaska, northern Alaska) Canada (Manitoba, Newfoundland, Labrador, Nunavut, Northwest Territories, Quebec, Yukon, Ontario), Denmark/Greenland, (plus Svalbard-Franz Josef), polar bears in the hunting path through the Canadian town of Churchill, Manitoba, so by autumn, churchill town will have a lot of polar bears on the seashore, waiting for sea ice to condense, The town calls itself the "Polar Bear Capital of the World.".
The world distribution of polar bears
Habitat
Polar bears are inhabited by ice floes of the Arctic Ocean. The loss of sea ice habitat due to warming poses a threat to the survival of polar bears. Toxic pollution in the environment and industrial development have a direct impact on the survival of polar bears, and human destruction is fatal to the survival of polar bears.
Polar bear habitat
Habits of life
Event features
Polar bears spend more than 50% of their lives looking for food, and when food is plentiful, they can eat a lot and store energy in a short period of time, and once food is scarce, no matter what season, they can quickly turn into a hibernation-like state, reducing the metabolic rate. Polar bears rely heavily on sea ice in their travel, hunting, resting, mating, and in some areas of their caves. Polar bears spend a short time together during the mating season, living alone most of the time. Polar bears spend little time in their lives walking and swimming, stalking prey, or feeding, and polar bears spend most of their time resting.
Polar bear habits
Rhythmic behavior
Polar bears carefully clean their hair. When the polar bear has eaten and drunk enough, it will remove the residue and blood from the food.
Eating behavior
Polar bears are the top predators of the Arctic. They prey on seals, especially ringed seals, as well as bearded seals, saddle seals, and crested seals. If seals are not found for a while, they also feed on walruses, beluga whales, seabirds, fish, reindeer, snow geese, grass seeds and berries. In the summer, if there is no preferred food, polar bears will also eat some berries or plants. At the end of spring and summer, they come to seaside areas to eat seaweed and replenish the minerals and vitamins needed by the body.
Sexual behavior
Polar bears mainly use stationary hunting. Polar bears see seals emerge from the water in the ice and will track closer and then catch it. Polar bears usually eat beluga fat and leave meat behind. Polar bears differ from other bears in that they don't hide uneaten food and eat it later, or even grow away after they have finished eating fat, because high-calorie fat is more important than meat. Because they not only need to maintain a warm fat layer, but also need to store energy for food shortages, polar bears do not store or cache uneaten meat like other bears.
Polar bears forage
Aggressive behavior
Polar bears emit, hissing, snorting, and bowing their heads to indicate aggression.
Communicative behavior
Polar bears communicate with body language, with polar bears shaking their heads left and right to show that they want to play, and adult bears asking for something from another bear nose to nose.
Grow and reproduce
Polar bears during the mating season the male will mate with multiple males and females until mating is successful. The mating season is from late March to late May each year, during which the female must mate with her companions multiple times to ensure successful fertilization. Fertilized eggs of polar bears are delayed in implantation, and the implantation time is from mid-September to mid-October each year, after 2 to 3 months, the cubs are born in caves covered with snow and ice. In general, two pups are born in one litter, and in the rest of the case, it is 1 to 3. The mother and the cub live together for 2.5 years, and the females mate and reproduce again after the cubs become independent. Females therefore have a reproductive interval of at least 3 years, although the reproductive rate is lower, but the lifespan is longer, and individuals with a lifespan of more than 30 years have been recorded in the wild.
Polar bears grow and reproduce as follows:
Growth phase
detail
Image
born
The cubs are born with their eyes closed, and their fur is very good, weighing about 600 grams.
Polar bears are born
grow
Polar bears provide all the care for their offspring, and the cubs live with their mothers for 2 to 3 years.
Polar bears grow
sexual maturity
Polar bears do not reach sexual maturity until they are 5 to 6 years old.
Polar bear maturation
procreate
The gestation period of polar bears is about 195 to 265 days. An average of 2 cubs are born in the mother's nest, and the number of cubs is about 1 to 3.
Polar bear cubs
life span
In the wild, the lifespan of polar bears is estimated to be 25 to 30 years.
Elderly polar bears
Species conservation
Endangered causes
Cause classification
Detailed reasons
global warming
Global warming has reduced the range of polar bear habitats (ice floes) and prey bases, threatening the survival of polar bear populations.
environmental pollution
Non-decomposable organic pollutants have posed a threat to them, such as organochlorine compounds in the environment, once accumulated, fully absorbed by the food chain, and then eaten by polar bears, affecting their nervous systems, reproductive systems and immune systems, resulting in a decline in disease resistance and a decline in reproductive success.
Artificial capture
Polar bears have always been a traditional hunting resource for the inhabitants of the Arctic Circle, and fat, meat and fur are the living resources of the locals, and they can also produce handicrafts for sale.
Population status
In the 20th century, polar bears in the United States (Alaska), Canada, Denmark, Norway and Russia had populations between 22,000 and 31,000.
Conservation initiatives
To protect their survival, the first International Conference on Polar Bear Conservation was held in Fairbanks, Alaska, in 1965, and the IUCN established a polar bear expert group.
In 1972, the United States issued a law prohibiting the hunting of polar bears except for survival needs.
By 1973, countries in the Arctic Circle, including the United States, Canada, Norway, Denmark and the former Soviet Union, had signed the Agreement on the Protection of Polar Bears, which, in addition to restricting hunting and trade, further provided for the protection of their habitats and cooperative research.
Following the inclusion of polar bears on the list of threatened animals under the Endangered Species Act in 2008, the United States developed the Draft Polar Bear Conservation management plan in 2008, which plans to implement six strategies for managing polar bear populations, including: limiting global greenhouse gas levels to levels suitable for polar bear recovery and protection; Supporting international conservation efforts for polar bears; Managing conflicts between humans and polar bears, co-managing Alaska Native Hunting; Protecting polar bear habitat; Reduce the risk of oil spills. At the same time, it cooperates with Russia to protect the polar bear habitat in the Chukota region of the Russian Far East and Wrangel Island.
In 2013, the five Arctic rim countries and relevant organizations also held an international forum to discuss and exchange views on the survival status and threats faced by polar bears, and summarized the achievements and experiences of countries since the signing of the Agreement on the Protection of Polar Bears 40 years ago. to restore as much of the damaged natural environment as possible in the Arctic.
In 2015, the United States developed the Draft Polar Bear Conservation and Management Plan, which plans to implement six strategies for managing polar bear populations. Russia has established more than 320,000 square kilometers of nature reserves within its Arctic territory for polar bears to inhabit, while carrying out garbage removal work in the Arctic to restore the damaged natural environment of the Arctic as much as possible.
Protection level
In 2005, IUCN's Polar Bear Expert Group upgraded polar bears from non-hazardous to vulnerable.
In 2015, polar bears were listed as vulnerable on the IUCN Endangered Species List according to A3c criteria.
In 2017, polar bears were listed as Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (cites the CITES Convention).
Research Results
On June 17, 2022, scientists posted in Science that they had spotted a distinctive group of polar bears in southeastern Greenland that used a mixture of freshwater snow and ice as a platform to ambush seals. The researchers say that as global warming and Arctic sea ice decreases, many polar bears face the threat of starvation, and this new population may offer hope for the survival of polar bears.