Researchers have once again mounted tiny cameras on the heads of hawks to study exactly how they hunt, and the resulting videos are extraordinary.
Previous research using similar techniques has already supposed that raptors use rapid head movements to gain a visual fix on their target of prey, allowing them to swoop down with pinpoint accuracy in one of the most dramatic hunting actions in the animal kingdom.
With this new research published in The Auk, a journal of the American Ornothology Union, biologists have a great understanding of just how these head movements react when the bird is searching for prey.
“The strategies by which foraging predators decide when to redirect their gaze influence both prey detection rates and the prey’s ability to detect and avoid predators,” the study’s authors report.
In one of the videos, a goshawk is perched on a tree in The Netherlands as he scans the ground for rodents. The hawk scans the ground but not by panning. Instead, it uses quick head movements in succession to almost take snapshots.
When a small animal is seen walking along the river, the snapshots still occur but each time its head angle changes with the rodent still in frame. That’s when it gets a fix and swoops in for the kill.
The biologists involved in the recent study went into a lot more detail into the exact ways in which the raptors move their heads to affect their vision and how it compares to other animals, especially primates.
“Unlike models that have assumed an average pause time or a fixed search rate, a stochastic decision-making strategy based on accumulating sensory inputs allows a balance between these multiple constraints without providing prey with predictable feedback,” they wrote.
Read the study in its entirety at The Auk.