Naked Legs
The brown, Circaetus cinereus, and black-chested, Circaetus pectoralis, snake-eagles are common large raptors in the Lowveld and distinguished immediately by their large yellow eyes and square-shaped heads.
Unlike other eagles, the snake-eagles have naked legs, which are covered in robust scales. This is an adaptation to handling snakes as the scales provide some protection from the strikes of snakes inaccurately grasped or not killed on impact.
Snake eagles lead a relatively solitary existence outside of the breeding season.
Head First
The brown snake-eagle is often seen prominently perched at the top of a tree from where it will descend on its prey. It drops onto a snake and crushes its spine with its powerful talons biting at the same time to crush the head. The snake is swallowed head first and may be regurgitated and re-swallowed several times until it is comfortably accommodated in the stomach.
Snake-eagles swallow their prey directly into their stomachs and unlike other birds, they don’t store snakes in their crops first. These eagles do take prey other than snakes including lizards, rodents, insects, birds and even fish and these items may be stored in the crop. Interestingly, the crop (a pre-digestion storage sack in birds) wraps right around the neck of raptors while in other birds it sits in the front of the neck. The black-chested snake-eagle exhibits a great deal of resourcefulness in catching reptiles fleeing fires by aerial perching at the edge of burning areas.
Aerial Perching
The black-chested snake-eagle is an aerial soarer and locates prey on the ground by hovering intermittently, more correctly called aerial perching as true hovering involves the ability to move forward or backwards which the snake-eagle can’t. The black-chested snake-eagle will descend on prey from 450 m up striking a snake behind the head which is crushed in the talons. Snake-eagles that don’t position their grip correctly are at risk of attack and even death by the venomous snakes that they hunt.
Snake-eagles feed their nestling chicks on snakes. These are taken to the nest already swallowed bar a section of the tail which is gripped and pulled by the chick and then swallowed with some contortions of its neck, which is believed to allow the snake to seat itself in the stomach.
By Megan Emmet