The experience of reintroduction of western capercaillie (Tetrao urogallus) and hazel grouse (Tetrastes bonasia) in the Novosibirsk Region, Russia

Aim. Evaluation of the effectiveness of reintroduction methods of western capercaillie ( Tetrao urogallus ) and hazel grouse ( Tetrastes bonasia ) born and raised in aviaries in the conditions of the West Siberian plain. Birds were released into nature from a collection that had been kept in aviaries for several generations. There were 6 mature females aged 1–3 years among the capercaillies. Four of those females were released in broods with chicks aged 2–5 days (2, 4, 5 and 6 chicks per brood). Adult females with broods were tagged with radio transmitters. In addition, older capercaillie chicks aged 3–4 months were released without adult females (40 individuals in total). All released grouse were chicks over the age of 3 months or mature birds. A total of 63 capercaillie and 28 grouse were released. Radio tracking, visual observations, surveys and reports from the local population about individual sightings were used to track their movements. Of the 4 capercaillie broods, the vital activity of one in its entirety was traced for 42 days. Six encounters of single capercaillie occurred 10–227 days after their release. They happened mostly near human habitation at a distance of up to 70 kilometres from the place of release. A female encountered in May of the year following the release was laying eggs. Eight visual encounters of grouse at a distance of up to 1100 m from the place of release were noted 2–139 days after release. Released aviary birds adapt to their natural habitat and are able to survive the most difficult winter period. Chicks with females can safely grow up in a natural environment until the brood break-up. The revealed range of the released capercaillie did not significantly exceed that for wild young birds. All the discovered released capercaillie showed attraction to human habitation areas and structures. In released grouse, the detected departure from the place of release is less than the comparable range for wild populations. All of their sightings were in forest areas characteristic of the species. The furthest movements of birds raised in aviaries are directed towards the same aviaries where the birds grew up.