Najin, a female northern white rhino, gets a pat from keeper Mohamed Doyo. Najin, who lives at the Ol Pejeta Conservancy in Kenya, is one of only five of its subspecies left in the world. Ben Curtis/AP hide caption

itoggle caption Ben Curtis/AP

This sea otter, about to eat a crab in the Elkhorn Slough National Estuarine Research Reserve, is cute, sure. But more importantly, it's indirectly combating some harmful effects of agricultural runoff and protecting the underwater ecosystem. Rob Eby/AP hide caption

itoggle caption Rob Eby/AP

A horse-drawn carriage operator waits for riders near Central Park in New York on October 20, 2014. Mayor Bill de Blasio is backing legislation that would ban such carriages in 2016. JEWEL SAMAD/AFP/Getty Images hide caption

itoggle caption JEWEL SAMAD/AFP/Getty Images

Frederic Cesbron (right) and Maxim Durand walk on the street outside the Hyatt Regency O'Hare hotel in Rosemont, Ill., on Sunday. Thousands of people were evacuated earlier after a chlorine gas leak at the hotel, which is hosting the 2014 Midwest FurFest convention. Nam Y. Huh/AP hide caption

itoggle caption Nam Y. Huh/AP