Historical changes in mortality patterns of diurnal and nocturnal raptors in the Czech Republic, Central Europe: 1913–2017

Abstract

Raptors are apex predators and essential environmental indicators of ecosystem changes, with anthropogenic mortality heavily influencing their population trends. However, mortality factors can change over time, potentially diverting attention from the underlying drivers of raptor declines. Therefore, a broader perspective beyond studying contemporary mortality patterns for individual species is necessary to prioritize conservation efforts across raptor species. Our study analyzed data from six databases spanning 1913–2017 for the recoveries of 24,443 dead birds, including 24 diurnal and nocturnal raptor species in the Czech Republic. Our results showed that direct persecution historically dominated raptor mortality, but contemporary patterns are shaped by different sources of anthropogenic mortality. Mortality due to vehicle collisions, electrocution or collision at powerlines, and other anthropogenic sources gradually increased from 1913 until 2000 but began to decline in the last two decades. After 2000, vehicle collisions caused higher mortality rates than mortality linked to powerlines and other anthropogenic causes. Natural mortality was lower than average anthropogenic mortality during 1913–1990 but prevailed over anthropogenic mortality after 2000. Species-specific variation in raptor mortality causes was also detected. Direct persecution was the most common mortality factor for diurnal species with higher human-wildlife conflict. Powerline mortality affected mainly farmland and larger raptors, while vehicle collisions were the most significant mortality factor for most owl species and other anthropogenic mortality for barn owls Tyto alba. Raptor conservation efforts should prioritize reducing direct persecution, but coordinated actions to mitigate vehicle collision mortality are also necessary for nocturnal raptors.