Question: Why this bird?

St Kilda Wren answered on 11 Nov 2017:

If we study the St. Kilda wren, we can learn lots about how animals evolve on islands and how they’re affected by disease and weather. The great thing about studying this species is that we can compare it with wrens from the UK mainland and elsewhere in Europe, which will allow us to see what changed, and when. It could also allow us to look as far back as the Ice Age and try to understand how populations were connected (and then got cut off), and how the distribution of certain species, like the wren, was affected by the melting ice.