Rainmaker870: Please note that I did not state or imply that bear spray is not effective against Black bears, only that it appears to be less effective against them than against Grizzlies. I apologize for any confusion.
One of the most significant studies was conducted by Dr. Stephen Herrero, probably North America's top expert on bear behavior over the past three decades and a Professor of Biology and Environmental Science at the University of Calgary in Alberta, Canada. The study is entitled "Field Use of Capsaicin Sprays as a Bear Deterrent" and was presented in "Proceedings, 10th International Conference on Bear Research and Management." There is other research being conducted by the Canadian Ministry of Forests, US Geological Survey (whose field geologists often operate alone in remote areas), and the US and Canadian park services regarding the effectiveness of bear sprays. Much of it is ongoing. I simply lack the time to reference it all. A good start would be Dr. Herrero's work. If you don't have access to the original study, he has a great book on bear attacks entitled "Bear Attacks: Their Causes and Avoidance" (Revised edition, copyright 2002) in which he both briefly summarizes the results of his study and discusses bear attacks in great detail.
KnifeaddictAK: There is a definite logic to your "preference" (and I am reluctant to use that word since I am sure you would prefer not to be attacked at all) for being attacked by a Grizzly rather than by a Black bear. I am not sure that I agree with you, but I definitely see the line of reasoning behind it and have met more than one native Alaskan who felt exactly the same way. There is no guarantee of survival in either case. It is all about odds.
Most Grizzly attacks are defensive attacks designed to eliminate a perceived threat to the bear, her cubs, or a kill it has made. Most of these attacks last a short period of time (though it probably feels like an eternity to the victim) and result in the bear leaving when it no longer perceives a threat. The Grizzly generally does not, however, bury the person and come back to eat later after a defensive attack. One should not automatically dive to the ground and play dead unless it becomes obvious that the bear charge is not a bluff charge. The ferocity and violence of even a defensive attack sometimes results in the victim sustaining fatal injuries. It is really about choosing between a very bad situation (playing dead during an attack and being mauled or possibly killed) and a virtually no-win situation (fighting back unarmed against a Grizzly and almost certainly being killed). Definitely a case in which an ounce of prevention is worth several tons of cure!
The far more dangerous attack is the rare predatory attack in which a human is attacked by a Grizzly as prey. The bear will continue the attack until the victim is dead and typically begins to feed on the human carcass, burying whatever is left over for a later meal (just as it does with moose carcasses and other prey it kills). The Grizzly remains close to the kill and approaching the carcass is extremely dangerous. Nearly all predatory attacks by Grizzlies occur at night, and the victim has all of the odds stacked against him as he is typically asleep when the attack takes place.
More than 90% of Black bear "attacks" result in only minor injuries (not requiring hospitalization), usually the result of humans trying to feed the bear, or stop the bear from eating their foods or wrecking a campsite. Most Black bears flee at the sight or smell of humans. A sow Black bear may swat the ground and huff while her cubs scurry up a nearby tree, but she rarely attacks defensively. Black bears simply do not demonstrate the aggressiveness of Grizzlies in defensive encounters except in extreme cases. A Black bear is often deterred by making noise or, if necessary, fighting back in these situations. Playing dead is not, to my knowledge, ever recommended.
In a very few instances, Black bears become predatory and stalk and kill humans as prey. These attacks nearly always occur in daylight. Humans are not as helpless because they sometimes are able to detect the presence of the bear and arm themselves or escape the area. In any instance in which a human is unable to escape, he should fight back for all he is worth with any weapon available. The bear will continue the attack until either the bear is driven away or until the victim is dead and will then commence feeding on the human carcass.
One of the most incredible survival stories of any bear attack is an incident which took place in Alaska in 1977 during which a female US Geological Survey field geologist survived a predatory Black bear attack. The helicopter pilot that dropped her off heard her distress call on her portable radio as the bear was chewing on her and returned in time to drive the bear away from her with the helicopter. The bear chewed off both of her arms and nearly killed her before being driven away. The story can be found in the above mentioned book by Dr. Herrero or in Larry Kaniut's book "Alaska Bear Tales" (the original with the red cover). It is an amazing account.
Any adult bear, Grizzly or Black, is easily capable of killing an unarmed human. Fortunately, the overwhelming majority of bears will move away at the first sign of humans and bears usually detect humans far earlier than humans detect bears. Knowledge about bear behavior, careful planning (regarding campsite location, cleanliness, and food storage), and an appropriate weapon as a last resort are all part of the survival equation.
I hope someone finds this post useful or interesting. JRF.
Notice: This post is for general information only and should not be construed as offering advice or recommendations in any way. Consult the appropriate Federal, State, or local agency for specific advice.
