BBC America: The start of the year is a time of extremes across Earth. From the realm of the Polar Bear the Arctic winds plunge the Northern Hemisphere into winter. While in the tropics, animals and humans have a different response to the season.
BBC America: May is a time of seasonal gear shifting and powerful forces of nature. In the heart of North America tornadoes tear across the plains as wild mustang herds gather. The end of the Dry in Southern Africa claims victims amongst the elephant herds.
BBC America: Summertime triggers some of the planet's great seasonal migration events: including thousands of Sock Eye Salmon reach the end of their journey to spawn in rivers attracting Brown Bears in a feeding frenzy.