Predation by human or animal is certainly a possibility. Old age or sickness may also be possibilities. In any case, she may or may not re-pair with another male. If she is on a flyway, she may be able to find another mate. If not, then she will do fine living on her own. Widllife is not afforded the opportunity to grieve for long periods of time like humans. Otherwise, this would be detrimental to their and their offspring's welfare.

However, if you think that she is in distress, please call the Swan Lifeline in Eton and they may be able to offer some assistance on who to call for a rescue. The Regal Swan