This is Bird Note.

Poison ivy is the bane of many outdoor enthusiasts.

The plant's distinctive leaves are made up of three leaflets,

and starting in late summer, its branches are full of whitish berries that are toxic to humans,

but not to a gray cat bird.

They'll land on Flausen ivy and pluck off the berries one after another.

Just like its leaves, poison ivy berries are rich in an oil called Eurushial that can cause a serious allergic reaction in humans.

But catbirds and other bird species just aren't sensitive to euryushial. Poisoned ivy berries are one of many fruits that help birds

survive fall in winter once insects become scarce. Other wild fruits such as pokeberry,

Holly, and Virginia creeper are poisonous to humans, but not to birds.

So the old survival advice to eat the berries that birds eat turns out to be pretty misleading.

Well, you probably want to stay away from poison ivy. You can improve habitats for birds by planting native fruit

bushes and advocating for wildlife-friendly gardening in public green spaces.

Learn more on our website, birdnote.org. I'm Ariana Rimmel. Support for Birdnote is provided by

Jerry Tone and Martha Wyckoff from Seattle, Washington,

and generous listeners around the world.