Hawks steer attacks using a guidance system tuned for closepursuit of erratically manoeuvring targets

Aerial predators adopt a variety of different hunting styles, with divergent flight morphologies typically adapted either to high-speed interception or manoeuvring through clutter, but how are their sensorimotor systems tuned in relation to habitat structure and prey behavior? Falcons intercept prey at high-speed using the same proportional navigation guidance law as homing missiles. This classical guidance law works well in the open, but performs sub-optimally against highly-manoeuvrable targets, and may not produce a feasible path through the cluttered environments frequented by hawks and other raptors. Here we identify the guidance law of n = 5 Harris’ Hawks Parabuteo unicinctus chasing erratically manoeuvring artificial targets. Harris’ Hawks use a mixed guidance law, coupling low-gain proportional navigation with a low-gain proportional pursuit element. This guidance law promotes tail-chasing and is not thrown off by erratic manoeuvres, making it well suited to the hawks’ natural hunting style, involving close pursuit of agile prey through clutter.Hunting styles and flight morphologies of aerial predators are adapted to their habitat structure and prey behaviour. Here, the authors reconstruct flight trajectories of Harris’ Hawks Parabuteo unicinctus and find that these follow a mixed guidance law that is not thrown off by erratic manoeuvres of prey.