THE sound of birdsong and a wolf's howl couldn't be more different – but what if that isn't always the case? Can a bird make more terrifying sounds than just chirps and actually let out a wolf's howl?

The term mid-size terror bird sounds kind of bizarre at first, as though terror birds, whatever they might be, come in a range of sizes, all of them a bit scary ...

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. A bird watching app is suddenly popular ...