The Brown bears at Ouwehands are all rescued bears ( dancing bears from Eastern Europe, circus bears ) and it could be that these are still marks from the chains they used to wear...
@FunkyGibbon No but a Russian brown bear is very possible, there is even a subspecies called collaris and there is a lot of variation between individuals whether they have this white ring and to which extent. If you google you can find some pictures that show this for other Russian bears, but this collar is indeed quite extensive.
