Join host Jeff Corwin as he connects with a collection of amazing mammals that face difficult conservation challenges. First, Jeff travels into the remote forests of New England to help care for a

Join host Jeff Corwin as he connects with a collection of amazing mammals that face difficult conservation challenges. First, Jeff travels into the remote forests of New England to help care for a rowdy group of orphaned baby black bears. Jeff learns about bear conservation and discovers the unique and friendly behaviors bear cubs have towards each other. Later, Jeff travels to Florida to meet orphaned baby manatees. Jeff learns about the threats to manatee habitat and what biologists are doing to save them. Finally, Jeff assists veterinarians to help two adorable opossums heal from their wounds and return to the forest. Video Transcript: Jeff Corwin: Mammals come in splendid variety, from the massive blue whale to the tiny deer mouse. Nearly all mammal mothers have live birth and all produce milk for feeding their young. At least some part of their bodies are typically covered with hair or fur at some point in their lives, and all mammals are endotherms, which means they can generate heat to maintain their warm-blooded body temperatures. Jeff Corwin: But tragically, today, nearly one quarter of all mammals are threatened with extinction, including at least 65 species in the United States alone. Scientists have estimated the total mass of all mammals on earth. They discovered that human beings make up 34% of this biomass, domesticated mammals account for 62%, which means only the remaining 4% are wild species. In the forests of New England, wild American black bears live in close proximity to humans. These bears are constantly threatened by pollution, vehicles and habitat loss, and black bear cubs are increasingly becoming orphaned. Jeff Corwin: Today, I'm visiting the Kilham Bear Center, where some of these bear cubs are given a second chance of survival.   Jeff Corwin: So this very precocious, absolutely adorable black bear cub is Marlow. This is Ethan Kilham and essentially Ethan, you are Marlow's stepmom, aren't you? Ethan Kilham: Yes. I'm the primary caregiver for the cubs, so basically I'm trying to be the best facsimile to a mother bear that I can be, so I'm feeding them, I'm introducing them to wild foods, wild things from the environment, stuff that they can play with. Jeff Corwin: Hi Marlow, no nibble. No, that's not... No, please. No, Marlow, no. So your instinct is to interact, but we don't want to interact. We want this bear to discover that human beings aren't a  part of his future success in life, right, Ethan? Ethan Kilham: Right. Jeff Corwin: We want him to be wild. Ethan Kilham: He'll be released at about 18 months of age and then he'll have all the tools to be a perfectly wild bear. Jeff Corwin: Marlow, what are you doing? Marlow, please get off the cameraman. Jeff Corwin: Marlow is still too young to be released, but today is a special day for two cubs named Flower and Dover. Today, they're going back in the wild and that's what we are about to do right now. For both our safety and the safety of these cubs, Flower and Dover will need to be sedated. To do this, Ryan will use a long pole fitted at the end with a small syringe of fast-acting sedative. Jeff Corwin: So what Ryan needs to do is get close to these bears, give them a quick poke, they'll go to sleep and all will be good. Jeff Corwin: No one likes getting a shot, especially a bear cub. Jeff Corwin: Success, Ryan? Ryan Smith: I think so. Jeff Corwin: Going to wait until he starts to get a little tipsy, which he is right now. We want to be there so when the bear goes to sleep, he doesn't fall and hurt itself.  Jeff Corwin: The sedative works very fast and makes Flower a little dizzy, but don't worry. We won't let him get hurt.  Jeff Corwin: There we go. There we go.  Jeff Corwin: We take Flower outside where the wildlife team will give him his final checkup. Jeff Corwin: So our first bear is nicely situated. Now let's go get the next bear. Jeff Corwin: All right. Okay. Now it's time for bear number two. Ryan's going to get in position. Thankfully, Dover's found a little corner to curl up in, so getting him outside will be much easier. Jeff Corwin: All right, if you just lower it down. Okay. I got him. All right. They are just such beautiful, beautiful creatures, so precious, such an important part of our wild legacy and to be a part of this program, it's amazing. Jeff Corwin: So what we have to remember is that these bears are no longer in control in the way their head is angled, their airway has opened or closed, and we have to constantly be vigilant to make sure these creatures aren't overheating, aren't stressed and are sleeping safe and sound. The team carefully records the cubs' temperatures, heart rate and size, what we call biometrics. Finally, it's time to give these cubs a small tag on each ear so they can be identified in the future... We've hit our character limit. Please leave us a comment for the rest of the transcript.

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