Winter is the best time of year to view the American Marten (Martes americana)! Don't let looks fool you, this adorable weasel is an incredibly agile and avid hunter. The Marten can climb down trees head first thanks to special joints in it's ankles, a relatively rare trait among mammals. Consider possible adaptations to a climbing lifestyle: "one challenge for mammals is climbing downwards on a tree trunk or other surface in a way that does not leave them vulnerable. Descending head first is im