In June of 2022, Adé Ben-Salahuddin worked as a volunteer research assistant on a tiny island off the coast of Maine at a Common Tern breeding colony. Every once in a while, the colony would suddenly go dead silent as all the adult terns took flight and dove over the rocky cliffs, returning soon afterward. This strange behavior is called a “dread,” and sometimes occurs without a predator nearby. It remains unclear why terns do it.
Dreading the Terns
Written by Adé Ben-Salahuddin
This is BirdNote.
[Common Tern calls]
I’m Adé Ben-Salahuddin, and in June of 2022, I worked as a volunteer research assistant on a tiny island off the coast of Maine with the National Audubon Seabird Institute. This was during peak hatch, the busiest time of year at these breeding colonies. Common Terns are the predominant species here, and thousands of them were emerging from their eggs. It’s a very noisy place.
[Common Tern colony calls]
But every once in a while, particularly in the evenings, the chorus would suddenly go dead silent
[Common Tern colony calls fade]
as every adult tern dove over the rocky cliffs, deserting their young. Then, rising on air currents, they’d return.
[Common Tern colony calls return]
This strange behavior is called dreading, and it’s not clear why terns do it. At first I thought it was a response to a predator, but often there’s no threat to be seen. Some researchers have suggested it’s a form of social bonding for the flock, to help them coordinate flight patterns for long-distance migratory journeys. Or maybe, it’s just for fun.
If that’s the case, it must be pretty entertaining, because terns will stop whatever they’re doing to join the dread [sounds die off again] – even if that means their hungry chicks will have to wait a few extra seconds for dinnertime.
Learn more about dreading at BirdNote.org.
Senior Producer: John Kessler
Content Director: Allison Wilson
Producer: Mark Bramhill
Managing Editor: Jazzi Johnson
Managing Producer: Conor Gearin
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Common Tern ML98873 recorded by Robert W. Grotke, and Common Tern ML221687541 recorded by Parker Davis.
BirdNote’s theme was composed and played by Nancy Rumbel and John Kessler.
© 2023 BirdNote February 2023
Narrator: Adé Ben-Salahuddin
ID# dreading-01-2023-02-28 dreading-01