Deep Look

🍄BEHIND-THE-SCENES: BIRD’S NEST FUNGUS

Added 2025-03-08 02:16:26 +0000 UTC

Hey Deep Peeps! Ever heard of bird’s nest fungi? If you’re a mushroom forager, they’re not likely to be on your radar. We filmed these curious mushrooms two years ago. They’re not poisonous, but they’re small (two can fit on your thumbnail) and don’t have much taste or nutritional value. They look like the tiniest of bird’s nests, with even tinier eggs laid by the tiniest of birds, all in service of their unusual reproductive strategy. The part that looks like a nest is a cup that holds sacs with millions of spores just waiting for a raindrop to launch them far and wide. Find out more about how we filmed them below.

And, if you missed seeing our bird’s nest fungus episode you can watch it here: This Mushroom Can Fly. We're highlighting this episode because it's still mushroom foraging season in the San Francisco Bay Area. )

Deep Look’s lead producer and cinematographer Josh Cassidy films a type of bird’s nest fungus called Cyathus olla growing in the mulch in a Menlo Park backyard. (Photo: Gabriela Quirós/KQED)

We used a high-speed camera for this episode, in order to film the mushroom’s egg-shaped spore sacs hurtling away. When we use a high-speed camera, whatever we’re filming needs to be very well-lit. Josh pointed four lights at the tiny bird’s nest fungi growing in the mulch. The brown-colored fungi are smaller than a thumbnail and blend in with the mulch. (Photo: Gabriela Quirós/KQED)

We set up a burette full of water so that the tip was 1.2 meters (4 feet) above the fungi. The burette allowed us to drip water onto the mushrooms below so that we could film their spore sacs flying away, propelled by the drops. (Photo: Gabriela Quirós/KQED)