The European roller breeds in the temperate zone. It is predominantly a lowland species, preferring altitudes up to 400-600m in central Europe, however it ascends up to 2000m in the High Atlas mountains, and up to 800-1000m in the Caucasus region.
The estimated global population is between 200,000-700,000, and 50-74% of these (i.e. 55,000-117,000 pairs) breed in Europe, with approximately 13,000-25,000 breeding pairs in the 27 EU member states.
Following a moderate decline during 1970-1990s, the species continued to decline by up to 25% across Europe during the following decade. It is now extinct in Germany, Denmark, Sweden, Finland, the Czech Republic, Croatia and Slovenia, and there are only a few breeding pairs left in Austria and in Slovakia.
The Hungarian population (roughly 1000 pairs) is stable, and remains an important part of the European roller population. Until the 1950s, the roller was a common breeding bird in Hungary, it was widespread throughout the country, including the Transdanubian region (the western part of the country).
The population decline accelerated from the mid-1970s, and all breeding pairs disappeared from the Transdanubian region by the early 1980s. Recent monitoring shows, that they have disappeared from the major part of their former breeding areas, only remaining on the Hevesi plain and Borsodi meadowlands, the Jászság and Kiskunság territories, and in South-east Hungary. The Hungarian breeding population was estimated between 400-700 pairs during 1995-2002, but by 2007, approximately 1000 pairs were recorded. The population growth was mainly due to nestbox installations.
The species is still quite common outside the Carpathian ranges. It is a regular breeder in the Dobrogea and in the Bărăgan areas, occupying all suitable habitats. South Romania (Olténia and Munténia) remains a stronghold for the species, and the Moldva area on the east host significant populations of breeding rollers. Few breeding pairs and small scattered populations have been recorded in the Bánság and Párcium areas.
Rollers used to nest across many regions of Transylvania too, however these breeding sites have become extinct over time.
Romania never had a complete census on rollers to date, so information on population changes and exact distribution data are currently unavailable.
The roller is a protected species both in Hungary and in Romania.
European roller distribution / Map: http://www.iucnredlist.org/details/full/22682860/0