Biologists on Twitter are trying to find the most impressive animal butt.
Gabriella, a 26-year-old biologist from the University of Edinburgh, told BuzzFeed News that it all started on Thursday evening with a photo of a musk duck bum.
"It started innocently enough," she said. "[It] was born out of all of those photos where no matter how hard you try you end up with a blurry shot or a bum shot of the animal."
"For each decent photo there will be dozens, sometimes hundreds of misses - and a lot of them are bum shots."
Biologists started sharing their own pictures, and the #WildBum competition was born.
Some bums were magical looking, like this sea urchin's.
Some bums were really big.
And some were really small.
Other bums were hard to miss.
Some animal bums were probably best to admire from a distance.
But doesn't mean they were any less bootylicious, like the toned bum of this Sitatunga.
And this spiky Turtle backside.
Other bums were cute and fluffy.
This Marmot had a nice round one.
Some biologists couldn't wait to share their favourite animal bums...
Like the flamboyant backside of the red shafted northern flicker.
And the beautiful blue bum of this Steller's Jay.
The Antarctic fur seal pup has a cute and squidgy one.
Thank you, biologists, for sharing such fabulous booty!
Fiona Rutherford is a reporter for BuzzFeed News and is based in London.
Contact Fiona Rutherford at firstname.lastname@example.org.
Got a confidential tip? Submit it here.