I came across this amusing bit in the last of the Jeeves novels, in which a birdwatcher plays a minor character. (He goes out seeking after Clarkson's Warblers in the vicinity of his beloved, so that he might catch sight of her through his binoculars.) This had me thinking—all these stories take place in a mythical stasis of Britain between the two Wars, but would birdwatching really have been that common in the 20s and 30s? Binoculars would have been pretty costly, would they not, before 'military surplus' and occupied-Japan entered the market? When did birdwatching really take off in the UK?'I had forgotten you were a bird-watcher till you reminded me just now. You went in for it at Oxford, I remember. It isn't a thing I would care to do myself. Not,' I hastened to add, 'that I've anything against bird-watching. Must be most interesting, besides keeping you' – I was about to say 'out of the public houses' but thought it better to change it to 'out in the open air'. 'What's the procedure?' I said. 'I suppose you lurk in a bush till a bird comes along, and then you out with the glasses and watch it.'
-Aunts aren't Gentlemen, P.G.Wodehouse