Don't know, as I mentioned in the thread I didn't get anything confirmed so could be incorrect, but there was two bears this size that were keeping close together as if they are siblings, and there was also a 'full sized' bear resting nearby. We only saw the two bears this size, we saw a further 3 at least that were all the size of your average American black bear
From the news on the Woburn threads, they have recently imported five new young animals to add to the existing Bears.So Javan Rhino's observation about siblng behaviour may well still probably be correct- they just weren't born at Woburn(or in the UK).