When camping in a bear country, will a tent provide an additional protection from bears, as opposed to just sleeping outside or in a hammock? Provided I take the usual precautions of keeping any food, toothpaste etc in some other place than the one I sleep at?
Your tent may not provide any physical protection, but your sleeping bag will provide some. Sleeping bags cover the vast majority of your body, and the thick material of a sleeping bag will initially provide minor protection from claws and teeth.
A common strategy for dealing with bear attacks is to employ counter measures. Obviously countermeasures are difficult to employ during sleep though. Having a sleeping bag protect you for 10 or 20 seconds prior to becoming shredded may be enough time to wake and employ countermeasures against the animal.
Obviously countermeasures need to be the end game in such a strategy though, because a sleeping bag will not protect against claws and teeth for long. Bear spray and firearms are both effective countermeasures, and several studies assert bear spray is much more effective than firearms - especially at close range and when employed as an area weapon in the dark.
Other tools might be a camp warning system to give an audible alarm after a trip wire is disturbed. This device pulls a pin out of a siren device, which activates and audible alarm. The pin is attached to fishing line which you can wrap around trees or stakes in the ground. You might scare yourself in the middle of the night if a raccoon trips it though!. This camp light activates on motion.
The following articles assert bearspray is the most effective direct countermeasure:
In my opinion, one of the best strategies for employing bear spray after being attacked during sleep is to have a tent mate spray the bear. Bears are solitary and don't attack in groups. A single bear is likely only able to attack a single person at a time. When camping in groups, the person or people not being attacked are in an excellent position to employ bear spray against the attacking animal. Line-of-fire issues score another point for bear spray over firearms in such a case, because your buddy might shoot you accidentally while targeting the bear. It's much easier to recover from pepper spray than a bullet wound.
In the year 2016 there is quite a bit of technology you can use for countermeasures against attacking bears. If you practice preventative techniques, such as storing odorous materials out of a bear's reach and away from the campsite, then the technology available combined with friends to employ the technology should be more than enough to stay safe in bear country at night.
EDIT: Long after answering this question, I came across a bear expert's answer to this tent question in a book titled Bear Attacks: Their Causes and Avoidance. His exact words are:
This guy is a bear behavioral scientist and biologist who's life's work is studying bear behavior.
No, a tent will not give you any protection from bears that want what's inside. If you want to use one thats fine, but don't go getting a false sense of security.
In some ways a tent could be an attractant if:
These smells can get into the fabric and stick around for a while.
There are a lot of backcountry veterans who sleep "open sky", even in winter using nothing but a water proof tarp. I have really enjoyed it, and it gives you a better sense of what's around you in the wilderness.
In high winds however there is nothing like a good double wall tent, but just remember:
A tent can provide a psychological barrier for the bear - which won't do much to deter it if it smells something it wants inside (food), but can prevent haphazard encounters.
For example, if a bear is wandering through your camp on its way to check out your expertly hung bear hang a tent will be a visual obstacle it will naturally move around / avoid, whereas a sleeping bag out in the open is more likely to be "tripped over" and raise its curiosity.
A hammock likely will fall somewhere in between - as it is higher, and more obvious. It might provide some psychological repellent for a bear, though I would imagine less so than a tent.
And the importance of psychological protection for yourself should not be under-estimated. If you have properly secured and bear-safed your camp, then worrying isn't going to help anything. A tent provides a sense of security, and helps you get a good night's rest.
Along these lines, the "11th essential" item for me when sleeping in bear country is ear plugs.
A tent may give you slightly more protection than sleeping out in the open, but not much. If a bear wants at you, the fabric of the tent is no match for his sharp claws.
Bears, both black and grizzly, have been known to cause severe damage even to buildings, high wooden fences, and even vehicles. I knew of an apple orchard that had an 8-10 ft. high wooden slat fence that a small black bear tore through to get at the fresh, ripe apples.
The point: Don't count on a tent to give you any protection. Keep your bear spray handy.
If you are going to use bear spray, sleeping under a tarp, hammock or otherwise, will give you a better line of sight/fire, and reduce the suffering you will likely experience from the indirect spray. Having accidentally set off a small amount of my bear spray in the side door pocket of a car while driving the AL-CAN, I can confidently say that an indirect spray in an enclosed area can be pretty bad, and spraying a full, adrenaline packed, shot of bear spray inside your tent will be only slightly better than being eaten by the bear, at least in the short term. As time progresses the benefits will outweigh the drawbacks. That is,of course, assuming that the spray deters the bear. If it decides to eat you anyway, then at least you will have the distraction of having been bear sprayed first.