No, I'm not in England for today's wedding of the decade - I'm at home watching out for one of our native sparrows, the White-crowned Sparrow.
Its relative, the White-throated Sparrow, arrived in mid-April; that's when I know to start watching for the white-crowned, typically a couple weeks later. But I do look over each and every White-throated Sparrow I see to make sure it's not a White-crowned Sparrow. That has been quite a job lately - yesterday, I had 29 white-throateds in the yard and the yard is swarming again today.
Here's what I look for to tell them apart:
1) The white-throated has a delineated white throat. The white-crowned sparrow does not, though the feathers directly below the bill may be a little more lightly colored. The throat on the White-throated Sparrow is sometimes very bright white like pictured below, but sometimes it's duller, even greyish. The white-throated's throat is often bordered with a little black trim.
2) The white-throated has yellow lores (the space between eye and beak). On the white-crowned, this space is black or brown. Sometimes the white-throated's lores are very bright yellow, sometimes they're more pale. On tan-morph white-throateds (bottom picture), they can be very pale. But if you see yellow, bright or not, it's not a white-crowned.
3) The top of head is a little flatter on the white-crowned, while the white-throated's head is more rounded. But as if to make things confusing, sometimes the white-crowned will raise the feathers on the head, giving it a more rounded look.
4) The bill of the white-crowned is pink to orangish; white-throated beak is more gray.
Use these clues in this order to help pick out those White-crowned Sparrows amongst the white-throateds in your yard. Have fun looking!