Editor of science news from the Year of the Great Tit Marko Mägi, firstname.lastname@example.org
Many know the various songs of great tits but few have heard the bird hissing like a serpent. Hissing can be heard when you come across a female bird sitting on her eggs in a nest box, elsewhere great tits will not use this call. It is caused by predators such as least weasel, stoat, pine marten, pygmy owl, stray cats that are threats to an adult bird in a tree hollow. Although a nest in a hollow is comparatively well protected from predators the hollow can become a mortal trap if the nest is discovered – the only escape route is controlled by the predator and in the worst case the predator may even be able to get into the hollow.