We see koalas as cute and cuddly symbols of their native Australia, but there's a lot more going on with these iconic — and in the wild, noisy and aggressive — animals than most people realize. Urbanization and deforestation is encroaching on their habitats and endangering their survival, a plight depicted in the documentary "Cracking the Koala Code" by filmmaker Tina Dalton, premiering May 16 on PBS "Nature."


"We are really moving into their areas, and so these small stands of forest are left there, and the koalas are having to move between these isolated islands or sanctuaries. The more they have to come down out of their tree and move across a road or through someone's backyard, they are really susceptible to attack from dogs and being hit by cars," says Dalton. "They depend on the eucalyptus that they have, and they depend on living life in a tree, and they depend on having other koalas around them. And that's become a very fragmented situation. They live a very marginal existence."


Dalton's documentary focuses on a colony in Brisbane, but the species is found throughout Australia, "and depending on which areas you are in decides what the plight of the koala is," says veterinarian Dr. Geoff Pye of the San Diego Zoo. "Overall, the conservationists and researchers have agreed that there's been a large decrease in the total number, but in some areas they are breeding so successfully that they are eating themselves out of food, and in other areas they're not doing nearly as well. Loss of habitat has been the biggest impact on them through housing development, particularly in Southwest Queensland. The result is small, isolated populations of koalas that don't have the ability to travel to the next small koala population."


Earlier this month, koalas were placed on the threatened list by the Australian government, which will go a long way to protect the species. The next step, as depicted in the documentary, is to understand koala communication and mating habits to figure out how they adapt — or don't adapt. "As these population numbers dwindle and they get fragmented, trying to ensure reproductive success is really important," explains Dye, whose zoo has the largest population of koalas outside of Australia. Its Institute for Conservation Research is studying koala vocalization and the role of scent glands in the mating process. "We're trying to understand the cues for male choice so we can match the correct koalas together."





NBC's "Grimm" was presented with the "Green Award" at the 33rd Annual Travel Portland Tourism and Hospitality Industry Awards on May 10 for its environmentally friendly practices. In line with the network's Green is Universal initiative, the Portland-shot "Grimm" has implemented on-set programs to reduce waste and energy, such as composting refuse and using biodiesel fuel. "Grimm," which has its season finale May 18, returns to production for its second season later this month.




Tune in: On May 30, Nat Geo Wild's Big Cat Special Event "Puma!" follows the elusive titular predator, a female and her cubs, in their southern Chile habitat. "Bones of Turkana," a PBS National Geographic Special premiering May 16 and repeating May 21, focuses on paleontologist and conservationist Richard Leakey and his work in Kenya, Africa over four decades of exploration and discovery. Shot in HD, the documentary features music by Paul Simon and the Kenya Boys Choir.


Photos courtesy PBS and Scott Green/NBC


Check out our celeb section and watch Ecollywood videos.