I was reading a magazine article at noon and it was talking about bears being a big preditor on fawns.  I remember the same kind of article I read some years ago on bears killing moose calves.

Wolves have been getting the finger pointed at them a lot lately but we should be reducing bears a little too if we want to help out our moose and elk populations.

The article I just read was about bears and white-tail deer fawns in the eastern states.

In one study they put radio collars on 108 fawns in a forested area and 110 fawns in an agricultural area.  Within 34 weeks half of those fawns were dead.predation accounted for 46% of the deaths.

In the forested region 37% were killed by bears and 32% by coyotes.

It said that bears take a lot of fawns in the first 20 days of their lives, then the bears didn't get any but coyotes and wolves continued to.

I reckon moose calves take a beating from bears.

Moose generally have twins but when flying surveys in the winter very few moose cows have twins with them in the western forested area.  In the east part of Alberta most cow moose have twins with them in the winter.

Lots of bears where we are and they are big time fawn predators.  We have seen/heard bears kill fawns 3 times while shed hunting.
Couple more studies - http://wolf.org/wolves/learn/basic/resources/mech_pdfs/201wolfandbearpredation.pdf.  In this one wolves and bears kill roughly equal numbers of WT fawns.
And another where 2-5% of the bears diet in the spring was fawns.
I think there are alot of factors, but for sure they are significant predators.  This was the main reason we started hunting bears as there are just too many where we are.

When I lived in Nipawin, Sask. in the early '80's, Fish & Wildlife biologists were puzzled at the low calf moose survival in the Cumberland Delta northeast of Nipawin.  A two year study revealed that the local black bear population was in the habit of following a pregnant moose cow, and while the cow was giving birth, the bears would be helping themselves to the calf being born.  Needless to say, bear season was opened with a vengeance.  I do not recall what the limit was, but I do recalee it being more than 3!!!  A few years later while reading an outdoor magazine, information indicated that the moose population had come back to quite a degree, however, still not to the point of where the population had been prior to the discovery.

Black bears are omnivores so they will eat just about anything. I never heard of them following pregnant moose around but anything is possible. I think alot of their diet depends on season and location.

I have always felt that bears are more scavengers than predators.  Perhaps, they get some fawns and calves, maybe more  than I think in some areas.  If we compare them to wolves though, I don't think they are in the same league.  Nature is what it is though, it will balance itself.  I am not a big fan of human intervention, but we are in it so deep now.