Sloths urinate and defecate around once a week because their bodies take that long to digest the food they eat.
Bees, butterflies, moths and beetles are on the decline in Europe. Flying insects are essential pollinators for food security and agriculture.
Photojournalist Brent Stirton has been named Wildlife Photographer of the Year 2017 for his shocking image of a black rhino killed by poachers for its horns.
Over millions of years, large herbivores such as certain dinosaurs may have played a crucial role in dispersing vital nutrients across continents.
Over 110 generations, males who had to compete with other males for female attention were able to produce more seductive melodies.
The stunning helicopter footage shows two of the huge marsupials punching and kicking at each other as another watches nearby.
The unusual behaviour is the first documented evidence of widespread interaction between the freshwater and saltwater animals.
Dolphin and whale societies are about as sophisticated as our own. They talk, have names, form allegiances, hunt together and work with other species. All they lack is thumbs.
Storm Ophelia is set to hit Ireland and parts of the UK with gusts of up to 80mph from the Atlantic, causing schools and airports to close.
The program at China Conservation and Research Centre for the Giant Panda has its most successful year ever, with 42 cubs born in 2017.
The gruesome "undertaking behaviours" were found to increase the chances of a new colony succeeding.
Fossils dismissed in the 1970s as a common species have now been identified as a new kind of ichthyosaur. Researchers made the discovery after exposing evidence of fakery.
Recent research suggests that around half of all dogs and cats in the UK are obese - and the problem is only expected to grow over the coming years.
Photographers are invited to submit wildlife, landscape, underwater and aerial images to National Geographic's 2017 Nature Photographer of the Year contest.
The survey documents the whereabouts of 31,000 vertebrates, highlighting regions around the world where biodiversity is particularly under threat.