Siberian Eagle Owl Project
After the 35 days’ quarantine period blood samples were taken from the trio for DNA sexing and they were found to be a male and two females – very good news for the breeding programme. We also sent blood samples for DNA analysis, weighed the birds and took measurements for research purposes.
An unexpected problem arose after their arrival. The male and one of the females looked different in colour, size and characteristics from the second female and also from our existing male Boris. Having all been injured in the wild in Siberia, they were undoubtedly Siberian eagle owls, but the big question for us was which sub-species?
After making extensive enquiries to the zoo in Siberia, and to other international organisations, and also studying Russian ornithological literature, we found that two sub-species of Bubo bubo live in the territory of the Tomsk area. These are Bubo bubo sibiricus and Bubo bubo yenisseensis.
The range of Bubo bubo sibiricus extends from the western foothills of the Ural Mountains to the valley of the Ob River in the east. The range of the Bubo bubo yenisseensis extends from the valley of the Ob River to the valley of the Tunguska River and Lake Baikal in the east.
The larger pale owl (Nadia) was found at the left riverside of the Ob, at the southwest of the Tomsk area. The other two darker owls were received from the right riverside of the Ob, at the southeast limits of the Tomsk area.
We discovered that we had a pair of western central Siberian eagle owls Bubo bubo sibiricus, and a pair of the Eastern variety Bubo bubo yenisseensis. We managed to verify this information after a visit and study of owl specimens held at the natural history museum in Tring, Hertfordshire.
The more unusual Siberian pair of Bubo bubo yenisseensis were named Olga and Tomsk. In March 2002 for the third year in succession Tomsk and Olga laid three eggs. However after the 35 days of incubation nothing appeared to hatch, so the eggs were removed and checked for fertility.
To our amazement two of the three eggs were in fact fertile, and heartbeats were recorded on our new digital egg monitor. The eggs were then rapidly placed in our incubator and six days later the first egg began to hatch.
We have discovered that the shell on Siberian eagle owl eggs is notoriously thick, having similar characteristics of a goose egg, and this required extra moisture to help the chick break out of the shell. Within 24 hours a beautiful chick emerged covered in soft white down and like very proud parents, we were so delighted to have our first Siberian eagle owl baby.
The second egg started to hatch shortly after, but this was a day premature, as the eggs are usually laid on alternate days. The chick broke out of the shell but the inner membrane failed to rupture and, very sadly, it died during hatching.
Our fluffy bundle was named Kansk after a geographical region near his parents home in Siberia, and we have established from DNA sexing that he is a boy. As you can imagine during the first few weeks of his life we were extremely anxious that this rare baby owl would survive, and it was nurtured day and night with love and care.
It would appear that this youngster is possibly the first to have been bred outside of the Russian federation, and Kansk will be retained for the future breeding programme.