Placer sheep

A placer is a sheep whose mother died while it was a lamb, and which has subsequently bonded to an object which it will not leave.

For placer behavior to occur, the ewe must die when her lamb is old enough to support itself from grazing; otherwise, the lamb will die as well.

Placer sheep are particularly difficult for farmers to muster in for shearing, since they will not go with the flock in the normal manner.

Also sometimes called a 'hermit sheep', although that term can have a broader meaning, including sheep which have become solitary as a result of other stressful events in their lives.

References

Oxford Dictionary of New Zealand English: 'placer, n., Farming'