Have you ever looked up at a bird sleeping on a tree branch and wondered how it does not simply tumble off? The bird may look completely relaxed, its eyes closed and its body resting quietly, yet its ...

The benefits of sleep are shared across the animal kingdom. Sleep saves energy by slowing down the metabolism and allows animals to avoid high-energy activities. For vertebrates, sleep is an essential ...

A few weeks ago when I was out cycling with some friends, we saw a few birds who looked like they were sleeping. Someone asked me what they were doing, and I said they were resting or sleeping but I'd ...

Editor’s note: This story was originally published in February 2018. Free time is dangerous for me. I ponder imponderable questions, like “Do birds sleep?” Well, yes, but not the same way we do, and ...

What new research on the avian brain and REM sleep in birds might reveal about our own dream lives. By Maria Popova I once dreamed a kiss that hadn’t yet happened. I dreamed the angle at which our ...

Forbes contributors publish independent expert analyses and insights. I write about biodiversity and the hidden quirks of the natural world. Frigatebirds can remain airborne for days at a time without ...