Efektywność projektów reintrodukcji głuszca (Tetrao urogallus) w Europie

The study focuses on capercaillie (Tetrao urogallus) and other Galliformes birds reintroduction projects carried out in Europe since the 1950s. In Germany alone, there have been eleven projects involving the release of a total of ca. 5,000 caprcaillies, mainly obtained from the closed breeding centres. The majority of birds died shortly after release. The high mortality was caused by great pressure from predators and the poor adaptation of the birds bred in captivity to the wild−life conditions. The high mortality among the birds from artificial breeding is associated with changed morphology (e.g. shorter digestive tract, less−developed pectoral muscles), physiology, and behaviour (insufficiently developed social and anti−predatory behavioural mechanisms). Survival rates among the birds released into the wild were primarily affected by the method of breeding and release, quality of habitat, and pressure from predators. The survival rates of translocated birds were higher than those obtained from traditional breeding in aviaries. Better results were also obtained with the 'born to be free' method of breeding and release based on social contact between the mother and chicks. The following actions are obligatory in reintroduction projects: predators reduction, evaluation and improvement in the quality of environment, as well as long−term monitoring of birds. The factors crucial for the effectiveness are: the total number of birds released, the number of released birds in subsequent years, and the overall duration of the project.