Orange flowers

Yet another 'gift' from Mother Nature... I have no idea what these are, but they have self-seeded at the back of the garden. I've watched first the leaves and then the flower stalk grow as I've been feeding the birds each day and finally this morning there were a couple of the flowers open wide. So this is my blip for today in the hope that one of you kind people can tell me what it is growing at the back of my garden.