After leaving the others, Evale quickly made her way towards the cabin. While she tried her best to sneak and find a good spot to rain down arrows on the enemies, she did not manage this. While most of the undead in this horde consisted of beasts of prey such as Direwolves and Arkbeasts, some were deers or even birds.
Both of whom seemed much more alive as the undead were careful when killing them, something not so easy to do against beasts who could fight back. In this case, it was not the seemingly healthy deers who betrayed Evale's location, but rather the birds.
While they lacked a way of communicating with others, they could still let loose a shriek born from hell. The decomposing throat of these birds robbed them of their beautiful songs, and this shriek embodied their anger at this fact.