https://apnews.com/c450660899dc47e9bf8b47d814644c3d

NEW ORLEANS (AP) — Scientists are using fake eggs to spy on whooping cranes in hopes of learning why some chicks die in the egg, while others hatch.

Data gathered by the spy eggs could help biologists in Louisiana and Canada preserve the endangered long-legged birds, which have made a tenuous rebound after dwindling almost to extinction in the 1940s.