The similarity of cats and herons on eye color and behavior is so striking that that alone is enough to suggest that more than chance is at work. Cats are the lightest eyed of mammals with 14 of 15 species in my database (93%) having yellow or yellowish eyes. Among families of birds, herons have the lightest eyes with 56 of 61 species (92%) having yellow or yellowish eyes. The close similarity in behavior of the two has often been pointed out with each family master specialists of hunting by means of ambush. Cats and herons patiently wait for prey to come near or they slowly stalk prey. They are prime examples of my contention that predators that specialize in ambush tend to have yellow eyes.
In one study [See Worthy (1978) in the annotated bibliography] I asked 15 ornithologists to make (blind) ratings of “quick vs. deliberate” behavior for all large families of birds. Herons were rated as the most deliberate family of all. If mammals were rated on the same scale, cats would surely be rated as one of the most deliberate families of mammals. [If you are thinking of “quick as a cat,” see my entry titled “Quick vs. Sudden.”]
Those species in these two families that do not have yellowish eyes appear to not use ambush as much as do the yellow-eyed species. Three of the species of herons that do not have yellowish eyes are night herons. Night herons tend to be more active hunters and rely less on vision than do other herons. This is especially true of the Boat-billed heron which is also the darkest-eyed of all herons. Among the species of cats, the ocelot has darker eyes (reddish brown) than does the typical cat. One observer states that ocelots typically hunt, “not by ambushing, but by running down their prey.” [Bauer, E.(1988) Predators of North America. New York: Outdoor Life Books p.63.]
June 15, 2006
Cats and Herons
Our Blog
