Red-breasted goose (Branta ruficollis)

The red-breasted goose is an endangered bird. I only saw one at Regent's Park, so I don't know if they are breeding here, but it's a non-native beautiful goose that normally lives in parts of Northern Europe. What I also find interesting is that there doesn't seem to be the volume of information on them that other birds have on Cornell's website or on the RSPB site, for example. It's not like they're a mystery bird, but most of the information seems to be demographic, little being given about their behaviours or nesting practices and what not. It makes it a little more special to have seen one, and I do hope there is a pair of them so they can create more!