The Spurn Effect
The Spurn Effect. If you haven’t heard of it, it’s a phenomenon whereby a twitchable rarity is quickly followed up by the finding of one or more rarities at the same site. Such as the recent county-first Rustic Bunting at Ham Wall, Somerset, seen by birders visiting for the River Warbler. There are possibly many reasons for it, but it’s usually attributed to lots more visiting birders on site to see the initial rarity - more eyes mean more birds are likely to be found. It’s called the Spurn effect because the high concentration of birders in such a small area is bound to turn up great birds. But what else might be causing The Spurn Effect and what does this mean for our birding? Well one answer might be that the favourable weather system which brought the initial rarity was responsible for bringing the other(s). In other words, this really was an isolated incident and the site is undergoing a purple patch due to good conditions. But what about when the birds clearly have different or