Burchell's zebra stallions, Rietvlei Nature Reserve, South Africa

© Richard Du Toit/Minden Picture

Happy World Laughter Day

Even though these Burchell's zebras are probably fighting, to us it kind of looks like they are sharing a laugh. And since today is World Laughter Day, we've been trying to imagine what kind of joke would make a zebra laugh. Why did the lion spit out the clown? Because he tasted funny. Maybe. Anyway, World Laughter Day is celebrated on the first Sunday of May to remind people of the very real physical and mental health benefits of laughter. It's no joke that laughter has a clinically proven positive effect on your well-being. And experts (yes, there are experts) agree that laughing lowers blood pressure, releases endorphins, works your abs, reduces stress hormones, and even boosts T cells that fight infection. Faking it still works, even if you're not feeling it.

The Burchell's zebra is named for William John Burchell, an English naturalist and explorer who in the early 1800s traveled extensively in South Africa, where he studied these and many other animals. The Burchell's zebra is distinguished by one or two faint stripes on its haunches that appear to shadow the bold stripes, but otherwise it strongly resembles other plains zebras. The social structure of Burchell's zebras is based on a stallion leading a herd of mares—the whole group is called a harem. A young stallion may attempt to lead one of the mares away to his own harem, an effort that may result in a rough confrontation with the resident stallion.