It might make it to Dorset, but quite a long way from Somerset:
https://www.thesun.co.uk/uncategorized/5648451/6ft-ostrich-like-bird-at-large-in-devon-has-locals-in-a-flap-after-menacing-kids-and-horses/

Mike

Sorry for an out of county post, but a Rhea is on the loose in Devon and can run at speeds of 40mph so those in the south of the county could be lucky. I have seen many of these birds in the wild in Brazil but not in UK.