New research says long-billed curlews listen to alarm barks from prairie dog colonies to protect themselves from predators. The curlews nest in grasslands, where prairie dogs also live. Experts say previous studies showed birds often eavesdrop on other bird species, but that there aren’t many instances were birds are documented eavesdropping on mammals. The research was published Thursday in the journal Animal Behavior. The long-billed curlew nests in short-grass prairie and incubates eggs on a ground nest. Curlews press their head, beak and belly close to the ground when they hear prairie dog alarm calls.