Bob: How quickly do lion cubs learn to swim? Is it a long learning process?
Peter Gros: Some lion cubs learn to swim within a few weeks, since they must nurse soon after being born after a 103-108 day gestation period. They must nurse to get the necessary colostrum from their mother, which contains antibodies in her milk within the first 24 hours. It is important within the first several weeks that the cubs become strong enough to follow their mother on land or in water, since they have no protection from packs of predators when they are left alone.

Meredith: Do the delta lions have any interaction with lions in the neighboring Kalahari Desert? If so, what is the nature of that interaction?
Peter Gros: They do have interaction with neighboring prides, which is very unusual since lions are so territorial. They establish their territories through a series of scent markings and roars. Lions can listen to the roar of a neighboring lion, and tell if it comes from a male or female, a friend or a foe, or whether they safely outnumber the roaring group nearby. There's always a fear that a dominant male may try and enter another pride and threaten the cubs. The Okavango lions are the exception. Groups of females have learned to hunt together to corner their prey on islands.

Jessica: Do GPS [global positioning system] collars have any long-term effects on lions' behavior? What about tranquilization?
Peter Gros: GPS collars don't have long-term effects on the lions. They've been used for years on many different species of animals. I've worked with them with polar bears and lions and other cats in the past. However the new GPS collars not only record detailed data daily, but in some cases are designed to fall off at a predetermined time. Modern-day tranquilizers are quite safe. Animals can be tranquilized very accurately at a great distance with a small dosage, and it can be reversed very quickly. Once a lion has been given the antidote, she can be on her feet within minutes with no side effects We've come a long way since the first lion show that I filmed in Namibia, southwest Africa, where lions had to be captured with nets. Thank goodness for progress!

Numairhawk: What is the required education to become a biologist or ecologist like the ones who studied the lions?
Peter Gros: I would say a degree in biology, and I believe many researchers have a master's or doctorate. However, many researchers spend time doing fieldwork, working with highly qualified and educated researchers early on in their education. Many universities should have Web sites to answer those questions in greater detail.

Big Bad Boop: I think I missed this significant detail, but over how long a period has this swimming trait developed/evolved?
Peter Gros: This has been happening gradually for years, but the Winterbachs were the first to notice the real adaptations to make their new hunting skills possible, and the first — to my knowledge — to document the lions' hair length changing and becoming longer. It's certainly the first time I'd ever heard of neighboring prides of lions working together for a common cause of hunting. After lions have made a kill, adults sometimes gorge themselves with 80-100 pounds of meat, but then must go seven to 10 days without eating again. As was mentioned, one out of every five attempts to make a kill is often not successful for the lions. I think those numbers could be much higher during the severe winter months, so it became necessary for females in neighboring prides to work cooperatively.