Left: hybrid Graylag goose, Anser anser
and Canada goose, Branta canadensis
Right: Graylag goose, Anser answer
The thing about knowing you don't know all the answers, but also knowing that nature is amenable to reason, is that when you see something that makes you curious, you know you will probably find the answer if you look hard enough. With nature, that answer will be interesting, thought-provoking and will mean you will understand nature just a little better.
We saw these two wild geese on on lake near Oxford the other day when we went for a long country walk with our grandson and his parents. My grandson would much rather talk about Minecraft and wasn't even interested when I showed him the hole where the little gall wasp came out of an oak-apple gall - how can that not be interesting? He'll soon be old enough to have that copy of Richard Dawkins' "The Magic Of Reality" I bought him when he was about 4.
Anyway, what we noticed about these geese was that, while they are obviously a pair and the one on the right is a perfectly normal-looking graylag goose, the other was a slightly odd-looking Canada goose. Canada geese are an alien species in Britain but have spread very rapidly throughout the Thames Valley and beyond.