First Rule; Wear sensible shoes.
These people are obviously amateurs. First, they did not bring enough clothing, or a large enough vehicle for the wildlife they intended to photograph. And secondly, they are not wearing sensible shoes. I visited a wildlife photo site recently which featured a close-up of a badger. For that shot I would have been wearing some high top leather boots with steel toes. Badgers are quick. They are low to the ground, and they have big teeth and claws.
Second Rule; If you can smell the animal's breath, you are probably too close. I love watching these wildlife guys on T.V. I just saw a movie on the life of Marty Stouffer, who's show Wild America, I watched for many years. During this same period, I watched Mutual of Omaha's Wild Kingdom with Marlin Perkins. I can still hear his high pitched voice directing Jim to jump from a moving vehicle onto the back of some ticked off animal they were attempting to photograph. Now these guys are on every channel. Not only do they photograph the animals, they have other guys who photograph them handling these dangerous beasts. I always worry that I may be watching the final episode in the series.
Third Rule; Never use the cuteness scale for determining how close you can get. In a visit to Yellowstone some years back we were told that while the Grizzlies are dangerous, more people are killed and injured by Bison. In Africa, most people know how dangerous lions and Nile crocs are, but they will gladly get in a fiberglass canoe for some close up photos of cute hippos. More people are killed by hippos than any other animal in Africa.
Fourth Rule; Always go with a buddy. If you are out front concentrating on the shot of your lifetime with a Nikon, make sure your buddy is behind you and is proficient with his Canon. Thank you for all your hard work in bringing us great wildlife photos to enjoy.
P.S. Fifth Rule; How did I leave this off the first time? It was my dad's cardinal rule for going into the wild. Always take a role of toilet paper with you. He died fairly young and I inherited his old hunting jacket. I put it on, put my hands in the pockets, and lo and behold there was a roll of toilet paper. Don't forget this one.
Horse sense is the thing a horse has which keeps it from betting on people. W. C. Fields