On this beautiful calm, sunny day with temperatures near 40 degrees, a British Broadcasting Company TV crew accompanied Lynn Rogers to Blackheart's den to film a segment for the new BBC Series "Extreme Animals."  The program focus is on extremely cold weather.  The 5-10 minute segment with Blackheart will be about black bear's ability to endure cold for five to seven months without eating, drinking, urinating, or defecating, while giving birth and nursing cubs in the den.  During the filming, Rogers ascertained that Blackheart's cute cub with the white V on its chest has its eyes fully open and is a female.  Another cub was earlier ascertained to be a male, leaving the sex of one cub in question.  Whether they are males or females is important to the research because males leave the study area at about two and a half years of age, while females stay for life.  Hopefully, this little female will survive and become a valuable part of our study of coexistence.  She already is providing footage that will endear bears to people.  She was front and center in the picture a couple times when Blackheart allowed Rogers to put a tiny infra-red camera on the end of a pole and record images that normally are beyond human view.  Blackheart sniffed the familiar camera and basically ignored it sliding under her chest to view the cubs underneath her.  While the camera was in place, Blackheart tucked her head under her chest, and the camera showed Blackheart licking the cubs as they nursed and possibly defecated.  Mothers eat the cubs' feces and lick up any urine, keeping the den fresh.   This also efficiently recycling any nutrients that could be of value during this period of fasting.  Blackheart hasn't eaten since September 16 (six months) and probably won't emerge for another 12 to 30 days.