Thursday, May 25, 2017


Two-egg clutch of Barn Owls (Tyto alba guttata) in a wall mounted nest box located in a green suburb of Zwolle, The Netherlands. An infrared camera connection showed that one of the two breeding birds disappeared during early egg-stage (halfway April), but the true cause of failure remains unknown. The box was installed over 20 years ago and became occupied by a single Barn Owl pretty much every winter and occasionally in summer. During summer 2015 a second bird appeared and a first breeding attempt was made the following year, which also failed during early egg stage. Today the box got cleaned out, the eggs were removed and 85 pellets were collected and will be used to identify prey items.

Sunday, May 21, 2017

Phylloscopus trochilus acredula

Northern Willow Warbler, but a very difficult ID… Captured, ringed, measured and released today @ VRS Hessenpoort, Zwolle, The Netherlands.

Wednesday, May 10, 2017

Training on Dutch andorinhas (May 10, 2017)

Capturing, ringing, measuring, bleeding and releasing Barn Swallows Hirundo rustica from a crowded barn in Hasselt, with Joop v.A. The cows were playing outside.

Sunday, May 7, 2017

A bit of twitching: Big Day Zwolle, The Netherlands (May 6, 2017)

1st prize: “Team Rocket (?; Jasper, Reinier & Tim)”. 120 bird species found during a 12 hour (06:00 – 18:00) bicycle ride. An equation of the previous record.