The number of migrating raptors counted at established watch-sites is used to study raptor migration ecology and to determine the conservation status of migratory populations of raptors. Among the behavioural and ecological studies, counts have been used to determine daily and seasonal timing of migration (phenology), species diversity, influence of weather conditions, flight patterns (e.g. soaring versus flapping flight), and to study flock behaviour and interspecific interactions.
Raptors are secretive, low-density birds, whose populations can be logistically difficult and financially prohibitive to monitor. A particularly cost-effective method for population monitoring of these birds is to sample regional, and even continental populations, at established migratory bottlenecks and concentration points. Long-term migration watchpoint databases have been used to track changes in raptor populations and migration behaviour, also in relation to climate change. In Europe, there are different projects and ornithological stations conducting long-term monitoring of migrating raptors, such as Falsterbo (Sweden), Tarifa (Spain), Lindus (France), Batumi (Georgia).