On Saturday 12 October 2019 Karen Vaartjes photographed a grey non-descript bird in her garden in Wijdewormer NH. She sent the pictures to a friend who was a birder and he sent it to Maarten Hotting, on of the regional admins of waarneming.nl (and also the one who discovered the Eurasian Crag Martins in 2006 in Hoorn NH). He made it publicly known at around 16:00 hours and eventually six birders made it before dark to look for the bird in the garden, but nothing was found. The next morning a second attempt was made at first light and now the bird was rediscovered. It moved to the garden at the house opposite of Karen's house. In stayed in that particular garden till Monday 14 October.
Identification was quite difficult. At first it was thought to be an abberant Icterine Warbler Hippolias icterina, than ID moved to Olivaceous Warbler Iduna pallida to an audacious bald ID of Upcher's Warbler Hippolais languida as suggested by Nils van Duivendijk, Dick Groenendijk and Diederik Kok. Help from abroad (most notably from Killian Mullarney who was involved in the ID of this bird) made clear the ID of the bird fitted Upcher's Warbler best, but some loose ends need to be solved, like the strange bill shape, the light culmen, lack of a light wing panel and lack of a loral spot. Most striking was the movement of the tail, up and down and from left to right. Also good were the white spots at the top of the tail feathers, the wing formula and - to lesser extent though - the tertial spacing.
Several good pictures by Jaap Denee were obtained on 14 October and a footage by Leo Boon (see below). Several droppings were collected and analysed and on 4 November 2019 it became publicly known the DNA matched Upcher's Warbler perfectly!
