I was a hardcore twitcher. I understand why the Cocos booby has Australia’s birders in a frenzy | Andrew Stafford

Twitchers can be the subject of derision but they have greatly expanded our understanding of birdlife in the age of extinction

The discovery of a black-headed gull in Geraldton, Western Australia, has put Australian birders in a bit of a flap. Normal people might wonder why, considering it is abundant in the northern hemisphere – it is the ubiquitous resident seagull in London. But twitchers, the bucket listers of birding, are proudly not normal.

As a semi-reformed, semi-retired twitcher, you can trust me on this. Frankly, flying across the country for a black-headed gull is no biggie. Every year, Australian birding’s elite travel not just to every corner of the continent but our extralimital territories – Christmas, Cocos, the Torres Strait and Macquarie Islands – in search of birds to add to their Australian lists.