Large, poisonous rats roam the Earth. It sounds like a post-apocalyptic scene from a B movie, but it’s not. Jonathan Kingdon, who mammalogists will know as the author of the The Kingdon Pocket Guide to African Mammalsand many other books on African mammals, and his colleagues discovered one of the most interesting and unusual behaviors in mammals.
You may have heard of freshwater sharks, but what about freshwater cetaceans? Pods of gregarious white belugas leave the ocean and move up large rivers (e.g. St. Lawrence River) in the summer months to feed on fish and benthic invertebrates. However, these beautiful whales are only temporary visitors to riverine environments. River dolphins are the true freshwater cetaceans.