Scientists used to think birds were split into two groups: those that learn or imitate sounds, and those that can't. But a tiny wren from Aotearoa New Zealand bridges the two.

But even the fiercest groups of birds have diminutive members, little wide-eyed eaters of insects and small rodents like the 4-ounce American kestrels and saw-whet owls.

Small birds spice up the already diverse diet of spotted hyenas in Namibia. Your friend's email. Your email. I would like to subscribe to Science X Newsletter. Learn more. Your name. Note.