The Alberta, Canada Grizzly Bear population is down 40% since 1980(1200 then,,,,,,,700 now)...........While not understood completely, female Griz here seem to be mating and having cubs later in life, having cubs in intervals of between 3 and 8 years................As a result, any female mortalities puts a severe drag on the population potential of this region...........

Grizzly bears were put on the province's threatened list two years ago when it became clear their numbers were declining. There are now about 700 in Alberta, compared with 1,200 in the 1980s.
In the Bow Valley, studies suggest female bears begin reproducing later in life and only have cubs every three to eight years.

Take No. 64, a 23-year old female grizzly who has had multiple litters of cubs, including three yearling cubs right now that are expected to stay with her for at least three years."It's extremely rare for us to have a bear that is in its mid-20s and lived the entire time in the Bow Valley," Michel said, noting she's been dubbed the matriarch of the Bow Valley. "She's a real success story."She'll probably have one more set of cubs after this and that will probably be about it."

No. 64 won't mate again until the cubs go on their own.Mating takes place in the late spring, when male bears travel long distances to find an available partner.Boo, a male grizzly bear in captivity at Kicking Horse Resort who was orphaned when his mother was killed in B.C., escaped his nearly nine-hectare enclosure in 2005 after catching the scent of a lady. He was neutered but escaped again in 2011, when a "gorgeous blond" showed up."Boo may have mated," Craig Bolt, operations manager for the resort, said of his first escape. "We just don't know."

The same holds true for Parks Canada experts who expect some of the female bears in Banff are "half pregnant," but won't know for sure until they come out of hibernation next spring.In the meantime, any bred bears will spend the summer gaining weight."In fact, that's what she has to do," Michel said. "She has to get as fat as she possibly can over the summer; otherwise she's not going to have enough body fat on to be able to have an actual pregnancy and give birth to those cubs. There's a threshold there."

So, a good buffalo berry season can actually lead to more grizzly cubs."She needs to be around 24 per cent body fat to actually have a successful gestation period," he said, referring to studies that have looked at the issue.In mid-November, the bears will make their way to the dens and the blastocyst implants in the uterine wall, making the bear pregnant."She literally goes to sleep and becomes pregnant about the same time she puts her head down in her bed," Michel said.