In their global review of raptor-wind farm interactions \citet{Watson_2018} found few studies that had simultaneously assessed population level effects outside recording fatalities at the wind farm itself. Those that did, found no population reductions for Golden Eagles Aquila chrysaetos breeding in the vicinity of the Altamont facility in California (Katzner et al. 2017) where migratory eagles suffered high mortalit\cite{b2008}), nor directly for Griffon Vultures Gyps fulvous (Martinez-Abrain et al. 2012) who found local effects on fertility and survival. However, Rushworth and Kruger (2014) modelling two species of vulture populations under threat of wind farms in Lesotho, (South Africa) found that even small increments in fatality rates due to wind farms would accelerate extinction of both threatened species. This highlights the need for population level assessments of highly impacted species, beyond merely recording fatalities at wind farm. It further highlights the need because high impact wind farms may act as sinks, that may not exhibit local population declines if spaces are quickly filled by floaters seeking high quality territories (cf Katzner et al. 2017).