I have visited a good number of national parks and protected forests in India and Africa and there are some animals you should always be worried about. In Indian context, Sloth Bear and Elephants are the ones that are high on threat levels to humans as compared to Tigers or Leopards.
Typically, in almost all the national parks, walking is prohibited for a commoner. The reason is clear i.e. to protect flora and fauna and then to prevent any conflict between man and animals while earning revenues. Also, animals don't get too used to people walking in forests and are typically comfortable watching us in vehicles/jeeps.
There are a very few cases where animals attacked or killed someone within the periphery of national parks. So, following simple rules chalked out by forest folks are enough self defence. Also, never try to cross the path of animals no matter how fast you can drive. So in a national park, it's always good to stay in your vehicle, keep a good distance between your vehicle and animal and do not disturb the animal.
Most of the animal attacks occur in buffer zones of forests/ national parks, near animal corridors or in villages surrounding the forest. Based on my experience here are a few things that you can do to reduce your chances of getting into a sticky situation:
1) Talk to locals about any rogue animal in the area where you are planning to venture. Most of the villagers on the periphery of forests know a lot more about the movement of animals than forest officials in their area. You will easily come to know about any rogue tusker or any kind of predator movement
2) Wear clothes that help you to be a part of your surroundings. Wearing shades of green or khaki in the forest makes it difficult to be spotted by animals who lack good eyesight(Elephants, Sloth bear etc.)
3) Avoid lotions or deodorants with strong fragrances. Your favourite deodorant or perfume easily announces your presence to Elephants, bears or rhinos
4) Observe the area around you carefully and keep a note of anything out of the ordinary. Fresh dung or broken branches or fresh footprints/pug marks must be dealt with extreme care and urgency
5) Lastly, travel in groups with someone having the knowledge of area where you are walking or planning to camp
Now coming to the self-defense part, here are a few things that you can do:
1) Carry a 4-5 feet bamboo stick and use it as a walking stick if you are stepping in an area where tigers or leopards frequently sighted.
2) Travel in groups of 3-4 and make sounds so that animals like bears or tigers know your presence in advance. Most of the sloth bear/ tiger attacks occur when they get startled by woodpickers or villagers
3) Carry bear spray or pepper spray, it can come handy when there is an animal ready to charge you.
4) Try gauging the wind direction while in forest areas. Tigers will always attack you from the opposite direction to wind in a jungle. Always try to be in the opposite direction of the wind if you accidentally come closer to an Elephant herd or a bear with its cubs
5) If you suddenly come in front of a wild animal, shout loudly, make yourself look bigger and slowly retreat without running. Avoid sudden movements and running will make things worse for sure
6) Lastly, keep quiet, stay calm and pray to god if you end up in a place where you are facing a tiger, elephant or a bear. Believe me, you won't be able to do much
Also, never venture in an unknown area without a guide, avoid any trekking or jungle walks after 5 PM and respect the wild. It's good to be a part of an adventure, but adventure without knowledge and preparation is a recipe for disaster.
Thanks,
Slushmaster