I've made a great start on all the endemic birds and added a lot of introduced ones too (many already very familiar to me as a Dutchman, I didn't realize so many of our common birds were brought over there).
Next up is vagrants, but there's just so many of them and it seems like a lot have just been recorded a handful of times over the past decades. Hardly worth studying for.
What are some more regularly visiting vagrants that I should definitely know how to recognize?
Looking forward to an amazing birding experience by the end of the year!