Brown bears battle for territory in Finland
Brown bears are, by all accounts, formidable predators and seeing two fully grown adult bears battling over territory is an impressive contest indeed. Brown bears battle for territory.
Often described as nocturnal hibernators, both of which are not altogether factual. Bear activity usually peaks using the early mornings and late evening, whilst activity occurs at any time through the day and night, it all depends on whether they are hungry.
Young bears are more likely to be active diurnally and many adult bears in low-disturbance areas are largely crepuscular. Brown bears battle for territory.
In the summer months, through through autumn, a brown bear can double its weight, gaining up to 180 kg (400 lb) of fat, on which it relies to make it through winter.
Although they are not full hibernators and can be woken easily if disturbed, both sexes like to hole up in during the winter months. Hibernation dens may consist of any spot that provides cover from the elements, as long as it’s big enough to accommodate their bodies. Caves, large crevices, or purposely dug cavernous tree roots are favourites.
Brown bears have one of the largest brains of any extant carnivoran relative to their body size and have been shown to engage even in using tools, requiring advanced cognitive abilities.
Brown bears are mostly solitary, although bears may gather in large numbers at major food sources such as rivers holding spawning salmon. When such social gatherings establish, the bears form social hierarchies based on age and size.
Adult male bears are particularly aggressive and are avoided by adolescent and subadult males, both at concentrated feeding opportunities and chance encounters.
Female bears with cubs rival adult males in aggression and are much more intolerant of other bears than single females.
Dominance between bears is asserted by making a frontal orientation, showing off canines, muzzle twisting and neck stretching to which a subordinate will respond with a lateral orientation, by turning away and dropping the head and by sitting or lying down.
During combat, bears use their paws to strike their opponents in the chest or shoulders and bite the head or neck.
Bear communication – Brown bears battle for territory
Several different facial expressions have been documented in brown bears. The “relaxed-face” is made in everyday activities and has the ears pointed to the sides and the mouth closed or slackly open.
During social play, bears make “relaxed open-mouth faces” in which the mouth is open, with a curled upper lip and hanging lower lip, and the ears alert and shifting. When looking at another animal at a distance, the bear makes an “alert face” as the ears are cocked and alert, the eyes wide open but the mouth is closed or only open slightly. The “tense closed mouth face” is made with the ears laid back and the mouth closed and occurs when the bear feels threatened.
When approached by another individual, the animal makes a “puckered-lip face” with a protruding upper lip and ears which go from cocked and alert when at a certain distance to laid back when closer or when retreating.
The “jaw gape face” consists of an open mouth with visible lower canines and hanging lips while the “biting face” is similar to the “relaxed open-mouth face” though the ears are flattened and the eyes are wide enough to expose the sclera. Both the “jaw gape face” and the “biting face” are made in aggression.
Brown bear mating season lasts from May through to July, reaching reproductive maturity at between 5 – 6 years old. Males first mate when they are large and strong enough to successfully compete with other males for mating rights.
Males take no part in raising their cubs and parenting is left entirely to the females.
Through the process of delayed implantation, a female’s fertilized egg divides and floats freely in the uterus for six months. During winter dormancy, the fetus attaches to the uterine wall. The cubs are born eight weeks later while the mother sleeps. If the mother does not gain enough weight to survive through the winter while gestating, the embryo does not implant and is reabsorbed into the body. There have been cases of brown bears with as many as six cubs, although the average litter size is one to three, with more than four being considered uncommon.
At birth, the cubs are blind, toothless and hairless weighing from 350 to 510 g (0.77 to 1.12 lb). The cubs suckle on their mother’s milk until spring or early summer and start to venture out of the den when they are 3-4 months old, usually weighing 7 – 9kg. When the cubs leave the den they are developed enough to follow mother over long distances to forage for food.
Brown bear cubs are inquisitive and quickly learn how to survive by following mother, hunting, fishing and learning how to defend themselves when needed.
Whilst apex predators, wolves are their adversaries, with wolves often taking the opportunity to pick off young bear cubs when mother takes her eyes off them.
In Yellowstone National Park, bears often steal fresh wolf kills. Yellowstone’s Wolf Project director Doug Smith wrote, “It’s not a matter of if the bears will come calling after a kill, but when.”