The bachelor thesis is focused on the evaluation of contemporary trends in birds monitoring in the countries within European union which shared their data from 2019 in the Pan European Common Bird Monitoring Scheme. In the thesis I accurately described the methodologies of birds monitoring and assessed them in terms of obtaining, evaluating and data processing. The methodological framework was extracted from the academic databases such as Web of Science, Springer etc. and simultaneously we completed and updated the information with the help of coordinators for national bird survey. The basis of thesis is the discussion about advantages and disadvantages of particular counting methods of common birds, the opportunities for improvement and their predominant contribution at the Pan European level in the data-assembling in the Pan European common bird monitoring scheme which provides us the accurate information for establishing the causality of negative population trends of common birds and more importantly the utilization of these trends as bio-indicators of contemporary state of nature.