The rollers are medium-sized Old World birds of open woodland habitats. They have brightly coloured plumage and a hooked bill. Most are found south of the Sahara. The genus Coracias contains eight species of sit-and-wait hunters. The European roller is similar in appearance and behaviour to the Abyssinian roller, which appears to be its closest relative. These two birds and the lilac-breasted roller seem to share a common ancestry and could possibly be considered to form a subspecies.
This site contains full information about European Roller Bird.