Gray-breasted Wood-Wrens sing a duet. Each sings a different phrase, yet the phrases are so closely linked, it sounds like one song. Such singing is called antiphonal song. The pairs use song to stake out and hold breeding territories. Dueting is most typical of birds that live in dense…

Tropical biologists Alexandra and Ben Freeman are in Papua New Guinea, documenting the effects of a warming climate on birds that live on the slopes of a remote mountain. Birds like this King of Saxony Bird-of-Paradise. Often, their research puts them in touch with unexpected beauty…