I want to know the answer to the following question:
Why do mountain and moorland breeders move only altitudinally?
All the background I'm provided with is that "Thus mountain and moorland breeders, such as wallcreeper Tichodroma muraria and white-throated dipper Cinclus cinclus, may move only altitudinally to escape the cold higher ground.". Is that enough to answer the question?
Answer: yes