Long-term population changes of high-bog avifauna in Latvia

High bogs as habitat for birds have experienced dramatic changes due to peat extraction in Northern Europe. The methods of peat extraction have changed since the 19th century. We classified bogs in three categories: (1) intact (no peat extraction); (2) old (renaturalized) peat extraction bogs; (3) bogs with active peat extraction. Old peat extraction sites have revegetated and naturalized, while extraction sites have little space for biodiversity. We studied bird population changes in Latvian bogs by analysing data from four national bird atlases: 1980 to 1984, 1985 to 1989, 2000 to 2004 and 2013 to 2017, as well from transect counts on 13 plots to assess quantitative changes over the years 2003 to 2014. Red Grouse Lagopus lagopus was not confirmed to be breeding in Latvia during the period of the study and has practically disappeared; it was observed in a single locality in Latvia. Steep declines within bog habitats in Latvia were observed for two species: Curlew Numenius arquata (bogs are the primary habitats for Curlew in Latvia) and European Cuckoo Cuculus canorus. Several bird species showed moderate declines in bogs over the study period e.g. Wood Sandpiper Tringa glareola, Common Crane Grus grus and Chaffinch Fringilla coelebs. One species (Skylark Alauda arvensis) showed a strong increase.There are considerable differences of avifauna due to peat extraction history.