Corvo, or the Corsican Nuthatch: A Tale of Two Twitches

In birding, the difference between a rarity and an everyday species is also relative. What is common in one location can be exceedingly unusual elsewhere. For the bird, this most likely means being lost — a wayward soul at the mercy of the wind or weather, exhausted and forced to choose a flightpath beyond its control. A Rose-breasted Grosbeak in Ontario is certainly a pleasure to behold, but displaced to Shetland it might draw in hundreds of camera-toting enthusiasts like the gravity of a superdense star. Alternatively, a rare species could also be an incomer in search of better places to live. The endemic birds of many islands started out this way, when a small population self-introduced and evolved to its locality. Such is the case of the Corsican Nuthatch, a bird found only in the high mountains of its namesake isle.