I have a series (c. 400) of point-counts of breeding birds, taken in the same localities in 1992-1995 and 2022-2023 periods. My aim is to obtain spatial information from the comparison between these two periods, possibly obtaining spatial indices, with the corresponding standard errors, permitting to compare the bird populations in this 30 year period.

Obviously, the ultimate aim of this work is to obtain information linkable with climate change and/or land use change in the corresponding periods.