Is the study of these animals really more important than their welfare? I can imagine this equipment -> https://img.atlasobscura.com/UC6CwEZZ85Acxf1_v1AK52TfEYf_ZWd... has a non-negligible impact on the animal's life.
As a practical matter, I imagine that white collar is less dangerous than the coloured tags which totally defeat their winter camo. (This is Canada, so colour is the correct spelling!) They would probably rather the collar than those tags be so easily seen by predators.
In most parts of Alaska, they have no bag limit on arctic hare, which are an abundant and renewable resource. This means it is legal for a hunter to go out and shoot 28 hares in a day.