If you missed our Polar Bear Alcatraz live chat with wildlife expert Peter Gros, we've got the transcript with your polar bear questions answered, right here.

Peter Gros: It's nice to be with you again to discuss one of the world's largest carnivores and how they survive in the most extreme climate.

iloveanimals321: I have heard that polar bears actually have black fur but the cold climate causes them to have hollow-colored hair. Is that true?
Peter Gros: Yes, it is true. When they're first born, they're almost completely light-colored, and then gradually as the months go by, you first start to see dark hair on the footpads (at about one month). The ears start becoming less pink, and eventually the hair around the top of the nose.

The hollow hair not only helps them with their buoyancy as they swim, but helps transmit heat to the inner dark skin to keep the bears warm while the outside of the thick hair is the same temperature as the outside climate.

»» Continued on Page 2 «« africanlioness: How thick is a polar bear's fur (how many hairs per square inch)?
Peter Gros: Polar bears have around one million hairs per square inch, similar to a sea otter. Humans have about 20,000 per square inch on their heads. The fur is so important to the polar bear's survival, not just as insulation but also as perfect camouflage as it stalks its prey on the ice flows. Stiff hair grows on the soles of its paws that not only insulate but provide excellent traction on the ice.

africanlioness: Are polar bears born with black skin or do they develop it as they grow older?
Peter Gros: Their skin gets darker as they grow, originating at the base of the hair shaft. Their fur appears white rather than transparent for the same reason as clouds; water foam causes reflection and dispersion of visible light. The fur absorbs ultraviolet light. The coat can insulate the bear to the point where they over-heat at temperatures above 50 degrees Fahrenheit; this is why you see polar bears in zoos with chilled cooling pools and refridgerated enclosures.

lionesspride: How slow/fast is the metabolism of a polar bear? It must be pretty slow if they only manage to catch their prey less than 2 percent of the time.
Peter Gros: It appears that they can alter their metabolism during periods of food depravation at any time of year. Unlike other bears, they can shift as needed into a hibernation-like metabolic pattern when confronted with periods of food shortage. This ability makes polar bears the most advanced of all mammals when it comes to dealing with food and water depravation (Nelson, 1987).

It is true that they often miss catching their prey. On the other hand, catching an adult ring seal or a walrus means they can gorge themselves with hundreds of pounds of fat and go long periods of time without eating again.

»» Continued on Page 3 «« polartaylor: My life-long dream is to meet a polar bear. Yes, everyone has told me I am crazy, but I am madly in love with polar bears, they are all over my room! I was wondering if you knew of any programs that could get me involved with polar bears.
Peter Gros: For years I've felt the same way that you do about this magnificent animal. The best place for controlled polar bear viewing is Hudson Bay at the small town of Churchill. They are accustomed to taking eco-tourists on the tundra to view polar bears who have come out of their dens with their cubs and are waiting for the pack ice to meet the shore ice so they can move out and hunt ring seals. These bears are accustomed to tundra buggies and are very curious. They walk within 10 feet of the visiting polar bear lovers. There's a group called Natural Habitat Tours, based in Boulder, Colo., who would be happy to give you further information about polar bear viewing with them.

sarahkobe: How long does a polar bear live in the wild and how long do they live in captivity? How long does a cub stay with it's mother?
Peter Gros: Female polar bears in the wild live to their mid-20s and early 30s. Males can live to their late 20s. In captivity, polar bears live to an average of 30-35 years.

Polar bears usually breed in April and May. Females generally keep their cubs for 2-½ years, which means they're available for breeding once every 3 years. The young are born in snow dens with their eyes closed, and weigh around 1-½ pounds at birth. Their body hair is so fine that at first glance they look like they're hairless. Cubs are nursed by their mothers until late March or early April, until they weigh around 25 pounds. They're then large enough to accompany their mother onto the sea ice. About two-thirds of the litters are twins, while single cub litters are the next most common. Triplets, while infrequent, are not rare, occurring in frequencies up to 12 percent in some populations.

»» Continued on Page 4 «« willipe9: How far south can a polar bear come and still survive?
Peter Gros: The polar bear's range limits are determined by pack ice. Their southernmost point is James Bay in Canada. While their numbers thin north of 88 degrees latitude, there's evidence of polar bears all the way across the Arctic. Population estimates are just over 20,000, with estimates of 60 percent in Canada. Some scientists recognize six distinct populations. They are: Wrangel Island in the Russian Far East, northern Alaska, the Canadian Arctic archipelago, Greenland, north-central Siberia and Svalbard-Franz Josef Land.

4spydy: Peter, Is there ever a chance where an orphaned cub will be adopted by another female?
Peter Gros: Yes, there are a small number of documented instances of adult females switching their litters in the wild, as well as adopting unrelated bears.

pcoffelt: It was heartbreaking to watch the polar bear situation. Do you know if the little bear made it or not? I cried through the whole show.
Peter Gros: I have not been in contact with the researchers since the show's completion, but I do know at that age polar bears are equipped to deal with the harsh environment. Polar bears will kill large animals, eat their favorite part first — the fat — and it's possible for a younger bear to feed on the remains while it's learning to hunt. I too have high hopes and do think it's possible for him to have survived.

renegade8: Thinking about the polar bear cub in the Alcatraz show, could a cub like that be transported to a zoo? I am curious where or how zoo polar bears become zoo polar bears.
Peter Gros: Polar bears reproduce very well in zoos and captivity now, so generally captive-bred polar bears were born in a zoo environment and that's all they really know. There have been cases in the past where bears have become too acclimated to people; they keep wandering into villages and lose their fear of humans. I believe there have been successful introductions to zoos in the past of these habituated bears.

Once a cub like the one in the Polar Bear Alcatraz special has moved off onto the pack ice, it still has a chance of survival depending on the success of the ring seal population. There is a chance that that bear did survive.

»» Continued on Page 5 «« saintsbaseball19: I was wondering what physical adaptations enable the polar bear to hunt prey as large as walruses and beluga whales.
Peter Gros: To begin with, it's sheer size, weighing almost half a ton. They have a long gap between their functional canines and their molariform teeth. That gap allows the powerful canines to penetrate deeply into the bodies of seals and other large prey without interference from adjacent cheek teeth. These teeth are well-suited to the task of grabbing and holding prey and shearing meat from the hide. Also, the claws of the polar bear are short and more strongly curved, which is good for clamoring over blocks of ice and snow, and securely gripping huge prey animals.

jessh44: I am curious as to the motivations and outcome of the research of the polar bears on the island. Aside from stating the mildly obvious fact that the bears are starving and cannibalizing one another, what exactly was done with the research in regards to the welfare of the bears? What overall effect do you believe broadcasting the slow, suffering of a young bear cub had in showcasing your research? Parallels to the overall suffering of the entirety of the bears on the island could be made, however, wasn't that shown enough through other footage of the bodies of bears on the island and in better taste?
Peter Gros: I believe the research is still ongoing, and is shared throughout the scientific community to help further understand this magnificent species.

I agree that the realities for wildlife survival in the natural world are very hard to view. The goal is to tell as truthful and as accurate of a story as possible, and hopefully affect public opinion about the plight of some of the world's species.

Peter Gros: Thanks so much for all your terrific questions. Sorry, but we've run out of time. I look forward to hearing from you again!