Here is something I found online that you might like to read
UPDATE FOR BEAR ENCOUNTER SURVIVAL GUIDE
This material is intended for those government agencies and companies who are using my first book as a safety training manual.
I started research for my second book in February, 1996, by interviewing bear attack victims and conservation officers. Each interview is carefully recorded, then typed, and sent back to the victim or survivor for an accuracy check.
In my first book, I concentrated on bear attack survival and deliberately avoided the human tragedy aspect of bear attacks. This next book will clearly demonstrate the horrific detailed nature of bear attacks, what went through the person's mind during the attack, and the effects of bear attack trauma.
While doing this research, I discovered some important points about encounters, attacks, and spray-use that I didn't know when I published Encounters.
#1 - I have recorded six recent encounters or attacks where the people involved yelled at a bear (both black and grizzly) that had already given an aggressive signal (blowing or growling), and the yell triggered an attack. In most of these cases, the bear had smelled the person and was standing on its hind legs trying to locate where the individual was. In each case, the person yelled in order to let the bear know where they were, assuming that the bear would then take off in the opposite direction. These were all defensive-aggressive attacks.
I also have two accounts of armed people getting bears to back down by aggressively yelling at them.
** I strongly suggest that if you are only carrying spray or have no defence system at all, do not yell at a bear that is blowing, growling, or popping its teeth and trying to locate you visually. Stand still and be quiet; it will most likely leave in a hurry after about a minute. This principle pertains to defensive-aggressive attacks only.
#2 - Black bears have hooked claws and can hook-climb trees all their lives. Grizzly cubs have the same capability, but in the fourth and fifth year of a grizzly's life, its claws straighten out and it loses the ability to hook-climb. Many adult grizzlies can still climb trees by lunging up a limbless trunk, by climbing on strong limbs, or by hugging the tree.
I have four recent accounts where adult grizzlies climbed trees and yanked the victims to the ground. I also have an account of a young man who scrambled up an eight-inch birch tree to a crotch 12 feet of the ground as an enraged bellowing sow charged him from 200 yards distance. The bear lunged up the tree, hugged it, and proceeded to climb to within 18 inches of its intended victim. At this point the bear received a heavy dose of bear spray down its gullet as it was breathing in, and the attack came to an end.
Alan Hobler climbed this eight-inch birch tree as a sow grizzly charged down this trail.
** Even though Alan Hobler's tree climbing strategy was successful, I have two accounts that were unsuccessful where people tried to spray the bear after climbing a tree. I believe that in most cases a person is better off to stand behind a tree and spray an attacking grizzly at about eight to ten feet distance.
#3 - This spring was a particularly bad year for predatory black bear encounters and attacks in northern B.C. It was a late cold spring with bears out of their dens and no plant foods to eat. In two barely successful cases of spray defense, the black bears were sprayed twice and still did not leave the area. The spray cans carried were the small size. The average spray time on bears is three to four seconds. This means that a small can has two blasts.
** I strongly recommend that you carry the larger 260 gram size spray or two of the smaller cans - you made need it. The spray must be carried on your hip in a holster or in a front pocket of a cruiser vest. Do not carry spray in the back of a vest - some people have paid dearly for this mistake. The bear must be sprayed at close range (eight to ten feet) so that if the wind is blowing in your direction, the bear will get more spray than you. Every person in a group must have spray. Two people standing side-by-side with sprays is a very effective defense system.
#4 - Phazer bear spray has issued a recall for some of its products. If you are carrying Phazer, contact your supplier and ask for information about the recall. If they do not know about it, ask them for the wholesaler's name so that you can call them.
#5 - Bear Guard has now come out with a 260 gram size canister. This is the size you need.
#6 - Counter Assault bear spray will be back on the Canadian market in the near future.
There is presently considerable confusion about how well sprays work against bears. The new viewpoint by some biologists is that sprays work well against grizzlies but not very well against black bears. There are some important principles being overlooked by these people.
There are two types of spray data: First, spray-use against habituated problem bears; second, spray-use against wild attacking bears. Most spray-use accounts against black bears are the habituated variety, and most spray-use accounts against grizzlies are wild attacking bears. Habituated bears respond differently to sprays than wild attacking bears. Habituated bears often move off a short distance when sprayed, then return quickly. Spray-use against wild attacking bears usually has a one-time skunk effect where the bear swaps ends and runs away blinded, swatting its face. But there's more to the picture than this.
When I carefully examine spray-use accounts against black bears only, I see three categories:
First is the habituated black bear in a park setting or on someone's porch. Under these circumstances, sprays are often ineffective.
Second is the attacking black bear in a defensive-aggressive behavioural mode.These are usually sows defending cubs, but there are few accounts in this category. This type of bear is almost always repelled by spray, much like the defensive-aggressive attacks by grizzlies.
Third is the most important category: predatory black bear attacks. These bears respond to sprays in unusual ways that you must understand if you are going to save yourself against a predatory bear.
The following account will show you how difficult dealing with a predatory bear can be:
On May 16, 1996, a T.D.B. engineer was working by himself in a cut-block north of Prince George, B.C. He was doing GPS locations of the creeks in the area. Earlier in the day the belt buckle had come off his belt (his spray was in a holster on his belt) so he had to put his bear spray in the back of his vest.
As he was moving along he saw a large black bear approaching from his left in a fast walk. As he turned to face the bear and started trying to reach the spray, he realized he wouldn't get it in time. The bear was only ten feet away when he threw his hat off to the side of the bear; it immediately pounced on the hat and started ripping it apart.
The bear was occupied with the hat for about ten seconds, then turned and headed towards its intended victim when it received a three-second blast of spray at a distance of five feet. It immediately backed up about ten feet, coughing and shaking its head. It put its face down into the ground moss and started rubbing the spray off.
The engineer started walking at a fast pace towards his pickup. After he travelled about 200 feet he saw the bear paralleling him off to the side. It disappeared, and then a couple minutes later came out in front of him and, once again, came at him in a fast walk.
The second blast was at about the same distance, and the bear reacted with the same backing up and wiping his face in the moss routine. The young man then semi-circled the determined bear and headed for the road in a fast trot. He kept looking back and sure enough, after a few minutes, the bear was hot on his trail but stayed back about 100 feet, not wanting a third blast.
Needless to say, this was the happiest engineer in B.C. when he arrived at the truck, because he had used up all of his spray with the second blast.
This account is one of five predatory black bear attacks that I have collected so far that happened this spring in B.C. The others are very similar in the amount of spray used and the determination displayed by the bear.
There are some important points to consider when using sprays against black bears:
# 1 - You need plenty of spray; the 260 gram size can or two smaller cans.
# 2 - Your spray must be in a holster on your belt for quick use.
# 3 - Everyone in a group must have spray and be ready to use it simultaneously.
# 4 - The effect on the bear may be temporary, so leave immediately.
# 5 - If you are dealing with a persistent bear and you use up all of your spray, beat the bear off with anything available.
When somebody uses a spray against a bear and the effect is minimal, it's hard for them to believe that sprays could work at all. But remember this: for every spray failure, there are three successes. I would be lying if I stated that I understood completely why sprays can fail miserably in some cases and work so dramatically in others. The most important effect a spray has on a bear is the asphyxiation aspect. It can be a matter of luck as to whether the bear is breathing in, or has its mouth open, when the spray hits it.
My next book will have many spray-use accounts that will help clarify what sprays can and cannot do.
Every year in B.C. there are three to four people who save themselves from death or injury with sprays. Even though spray success runs at about 75%, it is a far better strategy than the 'play dead/fight back' concept. Personally, I always carry a gun.
dlc
, oh and the reason there is dye in bear spray is to locate the animal after the fact and deal with it 
