Collaboration: Dr. Reuven Yosef from the Ben-Gurion University in Negev, Israël, Dr. Piotr Tryjanowski and PhD student Anna Kubicka from the Life Science University of Poznan, Poland

Scientists discovered my project and collection BCP (Black Code Project); they found data in the feathers of ‘my’ Great Grey Shrikes (Lanius excubitor) about the condition of the individual birds: whether they are strong, weak, young or old. According to the Israeli and Polish Shrike researchers, something can be learned from the feather patterns about the fitness of the birds and even about sexual selection for Great Grey Shrikes. This has to do with the degree of symmetry of the patterns, combined with data about the speed at which the feathers grow. The more symmetry, the fitter the bird, and the greater its chances of reproductive success, is in any event what I picked up from this.

In 2014 Dr. Reuven Yosef and I worked at the Naturalis Biodiversity Center in Leiden. He applies his ptilochronological research on the same individual Great Grey Shrikes which I observed and drawn in the BCP.
Ptilochronology is a cost effective tool for determining the nutritional condition of birds. The technique uses the daily growth of feathers to decipher diet and habitat quality as well as contaminant load. The growing bars are best seen under very good lightning conditions.Dr. Reuven Yosef wanted to investigate if there is a coherence between the results of his ptilochronological research and the symmetric / asymmetric patterns of the BCP. Anna Kubicka provides assistence by using Tps dig 2 program to measure these patterns with landmarks.

Prof. Reuven Yosef pricking with a needle between the growing bars of the T1


Fault and growing bars on the tailfeathers

3 tails fault bars

Image by Anna Kubicka using Tps dig 2 program.