This is bird note.

When birds swallow berries,

when birds swallow berries, they also ingest the seeds within the pulp. After just half an hour

or so, they dispose of the seed by passing it through their digestive system or regurgitating

it. Either way, the hard seeds wind up on the ground. There's an

evolutionary reason for this. Plants that evolved fruits with edible flesh

could attract birds to eat them.

Then the birds transport the hard seeds within the soft fruits

to new spots for them to take root. But birds do more than just carry the seeds. Their digestive system,

including their muscular gizzard, grinds away the hard outer

coating on seeds, making them more likely to germinate once the birds deposit them. What's more, seeds in a bird's droppings are prepackaged in

nutrient-rich fertilizer when they hit the soil.

Birds... soil. The benefits are mutual. A fruit-eating bird sows more fruit-bearing plants,

leading to more fruit for birds to reap in the future.

It's a relationship developed over millennia of co-evolution.

For Bird Note, I'm Michael Stein.

Today's show brought to you by the Bobbink Foundation.