We are currently waiting on tenterhooks to see whether Spring has arrived. It looks like it has, it feels like it has, but we have here before in other years and its not even March yet.
Birds are singing; new songs to challenge identification. In most case being alerted means that a view is possible to aid Id. This is when size comes into play. Just as we have all identified a large white object as a Swan or a small blue one as a Kingfisher, we can get it wrong with smaller birds. Here we see two finches, both sporting yellow and green plumage and sometimes misidentified. But, the Siskin on the left is much smaller than the Greenfinch on the right. Side by side - easy peasy; in the field less so. Other clues will help - Siskin may be feeding in Larches or Alders whereas Greenfinch might be at the top of a pine tree giving the sneezy call. Happy hunting.