Estimation of normal tear production in free-living Eurasian black vultures (Aegypius monachus) and griffon vultures (Gyps fulvus) in Dadia National Park, Greece.

The aim of this study was to record the Schirmer tear test I (STT I) measurements in free-living vultures in order to estimate normal values. The Eurasian black vulture (Aegypius monachus), which breeds in the Mediterranean region and Asia, is listed as near threatened; it is also classified as vulnerable at the European level and endangered in Greece. The griffon vulture (Gyps fulvus), once widespread across the continent, has undergone a dramatic decline which has led to its extinction in many regions.