Though I’ve written about many animals on this blog, there are always going to be animals I overlook, and groups I pull from more than others. For the most part I don’t do this on purpose, it’s just a thing that happens. And for some reason, when I’m picking animals to write about, I seem to forget that bears exist.
I’ve only written about one species of bear, the sloth bear, and even in that post I mention my neglect of the ursids. Apparently I’m no better now, but today I’ll write about brown bears (known as grizzly bears in some parts of their range) to try and make it up to this lovely family of animals.
Though brown bears are listed as least concern by the IUCN, they have been eliminated from much of their original range. They once lived in an extremely wide area, from northern Europe, Asia and North America to Morocco, Algeria, and Mexico. Today they are most commonly found in western Canada and Alaska, with small numbers still in Europe and Asia.
Brown bears are huge creatures, and are some of the largest Carnivores on earth, but size varies greatly within the species. The largest subspecies can reach weights of over 600 kg, while smaller bears can weigh as little as 80 kg. They range in length from one to almost three meters. In case you weren’t already scared of brown bears, just know that they can have claws as long as 10 cm. Don’t tangle with these guys, because you will lose. In fact, one website sums up the prowess of brown bears quite nicely: “they can kill a cow with one blow, outrun a horse, outswim an Olympian, and drag a dead elk uphill.” (Source)
Brown bears are most often active during the morning and evening, spending the day resting under cover. They often dig their own dens, using their giant claws to excavate dirt. These dens are used during the winter months, when the bears curl up and wait out the cold. This is not true hibernation, but the bears’ temperatures do drop a few degrees to consume less energy and they spend this time in a deep sleep. Denning time varies depending on location, with some populations barely denning at all.
Despite being huge and equipped with powerful teeth, jaws, and claws, brown bears are not exclusively carnivorous. In fact, they are one of the most omnivorous animals in the world, and will eat pretty much anything they come across. Plant matter, including berries, grasses and roots, are very important sources of food for brown bears. Depending on locality, different food sources are more or less common; for example, brown bears in Yellowstone feed on moths, eating as many as 40,000 in a day, while in Norway moose are the most important component of the diet, and in coastal North America, salmon are favoured during spawning season.
Mating season in brown bears occurs from May to July, with some males fighting over females. After fertilization, implantation of the egg into the uterus is delayed, until the females have settled down for the winter. Cubs are born six to eight weeks later, which means they are usually born while the female is still in her den, giving them excellent protection for the first weeks of their lives.
There are usually two to three cubs per litter, and mama bear puts a lot of effort into raising these little guys. She continues to nurse them until they are 18 to 30 months old, though they will supplement their diet with other foods by five months of age. Brown bear cubs stay with their mothers for at least two years, more commonly living with her for three or four years. They become sexually mature at four to six years, and can still be reproductively active at 25 years old.
I had the fortune of seeing a grizzly bear at Grouse Mountain in Vancouver a few years ago. It was in an enclosure, so I was perfectly safe, but I was able to admire the sheer size and power of the magnificent beast. It’s all very well to say they can weigh 600 kg and have 10 cm claws, but until you see it, it’s hard to fully appreciate them. And they should be appreciated, because these are really some amazing animals.