Hello and welcome. This. The Science of Birds podcast is a lighthearted, guided exploration of bird biology for lifelong learners.

This episode, which is number 52, is all about giant birds. The vast majority of birds living in the world today qualify as small animals.

Most of them would fit in the palm of your hand, and they're so light that you'd hardly

notice the weight. But today, today we're talking about bird species that are way, way

bigger than your average chickadee or finch.

Notice that I said species there.

We're talking about entire species made up of extra large birds.

So this is not about a few individual birds that happen to have mythological proportions,

like the avian equivalents of Goliath in the Bible, the jolly green giant, Paul Bunyan, or the big friendly giant,

our focus will be on evolutionary lineages that spawned some very large bird species,

species whose ancestors had been much smaller, millions of years earlier.

We'll look at a bunch of interesting giant birds throughout history.

Then we'll talk about some scientific explanations for why these critters got so big in the first place.

Okay, without further delay, let's get into it.

Birds are dinosaurs, right? You know this, I know this, your dog knows this, but on the off chance that you didn't

know that birds are dinosaurs and you're currently going into a convulsive fit of shock and

disbelief, might I suggest you go back and listen to the very first episode of this podcast?

That might calm you down. Being dinosaurs,

birds had some pretty massive ancestors. When we look back into the Jurassic epic, we find that

some of the direct ancestors of living birds were theropod dinosaurs weighing over 500 pounds, which is about 227 kilograms.

These animals then evolved to become smaller and smaller through natural selection,

generation after generation. After 50 million years of this miniaturization process,

...