thick/thin on the ground
thin on the ground
Not plentiful or abundant; scarce. Primarily heard in UK, Australia. That type of bird is thin on the ground these days—I hope it's not going extinct.
thick on the groundBRITISH
If people or things are thick on the ground, there are a lot of them. As buyers are not thick on the ground at the moment, this could be a good time to get a good deal. Jobs are not exactly thick on the ground in these parts.
thin on the groundBRITISH
COMMON If people or things are thin on the ground, there are very few of them. Good players are thin on the ground and clubs are having to recruit abroad. Yacht facilities are a bit thin on the ground in the remote Falkland Islands.