Ringers’ DigiGuide is based on photographs of birds caught in the ringing program at Ottenby Bird Observatory, SE Sweden. The website was opened to the public in February 2015. By then, the collection of digital photographs at Ottenby contained close to 70.000 images of 3.900 individuals representing more than 230 species. When released, the guide contained 34 species, but new additions are made continuously and eventually we hope to be able to reach c. 100 species, shown with complete sets of images of all age and sex categories during both autumn and spring.

Each image is accompanied by a caption in which a number is given within square brackets. This number refers to the unique number of the ring that was applied to that specific bird and was included here to give the reader an opportunity to separate and to refer to different individuals. Additionally, the number makes it possible for us to track biometrics, moult score and other data collected during the ringing. In a few cases we have used dead birds (found dead under the nearby light-house) in order to complete the photographic samples. When dead birds are shown, the number has been exchanged to the term ‘specimen’.

The birds caught at Ottenby are on migration, and we rarely handle birds where we have ‘tangible proof’ of the age or the sex (e.g. recaptures or breeding pairs). Hence, the age and sex given to the birds in this guide reflect our interpretation of present knowledge, but should be regarded as open for discussion.

The photo lab
The photographs in this guide have been shot with a Nikon D300 (up to spring 2015) and a Canon 7D Mark II (from autumn 2015 and onwards). The studio flashes have gone through some changes over the years, and that’s why we suffer from some variations in the light conditions in the images. The levels have been carefully corrected in Photoshop, but clear variations are still seen. In other words – some photos are good and some are bad, and the latter ones will be replaced as soon as better options are available. During autumn 2014 we installed a professional set with two Elinchrom flashes and the white-balance was fixed according to the 12% grey background. Because of this we have reasons to hope for better (and much more uniform) photos in the near future.

Acknowledgements

3.900 birds are not photographed without A LOT of hard work. We would like to express our deep gratefulness to our (voluntary based) staff that have worked with us during the years! We love you! Really! Further, we would also like to thank Gabriel Norevik for technical support in the photo lab as well as for developing our standard manual for handling and photo-views. Gabriel, together with Aron Edman and Simon S. Christiansen have also been invaluable discussion partners during much of the writing of this guide, and their deep knowledge on the subjects have been crucial. Finally, it must be acknowledged that Lars Svenssons’ Identification Guide to European Passerines together with Lukas Jennis’ & Raffael Winklers’ Moult and ageing of European Passerines are important sources for anyone learning the art of ringing, and much of what today is considered as ‘common knowledge’ originates from these two references.

Enjoy the birds!

/Magnus Hellström, director of Ottenby Bird Observatory