We estimated adult Black Harrier annual survival probability to be \(0.692\pm0.152\) (SE) from the survival analysis of \citet{Garcia_Heras_2019} GPS tracking data. Using \citet{Collingham_2014} model for Southern African birds adult survival we obtained slightly higher estimates of 0.75 (using female body mass) and 0.76 (using male body mass). For both these estimates we used a mean clutch size of 1.65 \citep{Garcia_Heras_2016}. We finally settled in taking the average of the highest and lowest values used an average annual survival probability of 0.72.
The parameters used for the simulation of population dynamics are presented in a table.
Considering the baseline scenario, (i.e. no birds killed by wind farms, a natural annual decline of 1% and adult survival set at 0.73, Black Harrier populations are expected to survive over 500 years (Figure ......). Population trajectories  change rapidly from this natural mortality scenario when fatalities at South African wind farms increase to five adults per year. At such rates population extinction would be expected in just over 100 years (figure \ref{459965}).