Science

Crocodile Eyes are Designed for Lurking and Hunting

Crocodile eyes are watching you. The thought of being stalked by a crocodile is enough to make anyone sweat profusely. In some parts of the world nipping to the waters edge for a quick drink is not good advice. Crocodiles aren’t just scary to most people simply because they have huge teeth and a fierce bite, though. Crocodiles lurk and pounce on their prey in a violent attack appears to come from out of the blue. The crocs you see will lurk just beneath the water, with only their devious mean looking eyes keeping a lookout for something delicious — like one of us for example.

In a recent study it has been shown that a crocs eyesight is pretty decent indeed. The new research shows that, while a crocodile may not have as good eyesight as you or I for example, it’s vision is well adapted for craftily lying in wait at the water’s surface for the perfect moment to strike and lunge at it’s unsuspecting prey.

Crocodile Eyes are Designed for Lurking and Hunting

Nicolas Nagloo and his academic colleagues from the University of Western Australia in Crawley recently investigated the eyes that were taken from three young saltwater crocodiles and also two young freshwater crocodiles.

“Both Australian species of crocodile possess a bright yellow iris, a slit pupil and a relatively large lens,” the team notes. Such features in the crocodiles eyes, that were known before this study, are useful for seeing prey and other objects in low light. (The animals, though, don’t have great vision underwater.) Crocodiles also possess a “mobile slit retina” which assists the crocs in controlling just how much light reaches the eye during the day time.

A study of the cells and dissections of the crocodile eyes revealed three types of single cones. This suggest that the crocodiles can see colors in their field of vision pretty well. However the freshwater crocs appear to be a bit more sensitive to the color red than their saltwater cousins. These crocs which are known as salties in Australia may help the freshies see better in streams and rivers.

Each species of crocodile further have a horizontal streak of high spatial acuity. This acuity is what enables the crocs to search for their prey without ever having to move their heads. Meaning that they do not have to make any movement that might give the game away.

That the two species of crocodile have eyes that are so strikingly  similar is somewhat interesting given that these are crocodiles and reptiles separated by some 12 million years of independent evolution. They live in different habitats and prefer to hunt for different prey. for example the freshwater crocs prefer smaller animals and more marine life. Yet each species of crocodile have developed a similar style of hunting their prey.

A style in which the crocs lurk menacingly just beneath the water line and scan the immediate surroundings for a suitable tasty meal. The crocodiles, this research demonstrates have eyes that are specialized to aid in such attacks. Beware the next time you head down to the waters edge. You never know what might be there just under the surface of the water.