In New Zealand, aerial culling had the greatest effects on red deer abundances in open habitats such as grasslands and subalpine shrublands [120, 21]. However, the aerial control of deer in tall forests has been less successful [20, 22]. In Australia, aerial culling was used to remove the last remaining goats from Kangaroo Island [23] and has been an effective control method for goats in arid environments [24]. However, in forested and rugged terrain, aerial culling of goats was ineffective, with only 31% of known animals culled [19]. Similarly, aerial culling for pigs can reduce populations rapidly and extensively where there is good visibility [16, 25, 26, 27]. Yet, pigs frequently take cover in thick vegetation, limiting the effectiveness of aerial culling [18]. Low probability of visual detection during aerial culling can result in the mistaken assumption that populations have been reduced to acceptably low numbers, premature cessation of control, and higher risk of population recovery [17, 19, 28, ].