Images from The Center for Biological Diversity Talk about Call of the Wild. A new iPhone app from The Center for Biological Diversity puts the sounds of endangered animals on your cell phone. You can literally hear them howling (or screeching, or singing, or growling) for help. But what makes the app special is that you can respond. The Wild Calls app is possibly the very first app that uses "Push Notification" technology for environmental education and activism. Check out the animal calls you can get on your phone. ...Read the full story on TreeHugger