How common is hybridization really? Probably more common than you think. Some estimates suggest that at least 9% of all bird species have interbred in the wild. A case-in-point is this apparent male hybrid between a Great Sparrow and Cape Sparrow that Ursula Franke-Bryson ringed in Namibia. I hope that this short guest blog from Ursula will entice birders to keep an eye open for the unusual – even with birds as everyday as sparrows!