The cuckoo has joined Britain's "red list" of endangered birds, researchers said Thursday. Boasting an unmistakable two-note call and noted as a traditional harbinger of spring, the cuckoo has joined 51 other species of birds considered to be in danger of dying.

The assessment comes from the Royal Society for the Protection of Birds that added the cuckoo to the endangered for the first time along with such birds as the lapwing, tree pipit, wood warbler, yellow wagtail and herring gull. Conservationists blamed the situation on loss of habitat caused by intensive farming techniques, climate change and development.