This is BirdNode.

In the UK for years, milk was delivered to your front door in bottles with foil caps.

Great tits, a common songbird in the UK, learned how to peck through the foil to get

at the cream, a skill spread, but how?

To find out, researchers launched a series of experiments.

Males from different subpopulations were captured, trained in one of two different, but equally

effective ways of opening a box to get food, and re-released into the wild.

Knowledge of how to open the box spread rapidly within 20 days, and most of the birds that

learned the trick did it the same way the trained bird in their group did.

Clearly, they learned how to open the food box by observing others that already knew

how to do it.

What's more, when birds moved between different cultures, they learned the prevailing way to

open the box in their new community.

Social conformity is a powerful force for birds as well as people.

But when the researchers did a follow-up experiment and changed one method of opening the box

to be more effective, nearly half of the birds switched to the more effective method in

just 14 days, it seems that great tits can stand up to peer pressure if they see there's

a better way of doing things.

For Birdnought, I'm Michael Stein.

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