Wednesday, January 22, 2014

Eyes on Ears and Mouth on Toes

Despite the clever if misleading title, we will not be talking about mouths on toes today (although many creatures such as butterflies can taste with their feet).  I just said that to make it sound like the line from the classic song "Head, Shoulders, Knees and Toes" by Bob Dylan.  Instead, we are going to be talking about eyes on ears: eyespots, at least!
A picture of one of the Amur tigers at the Denver Zoo.  See those white bars surrounded by dark fur on the ears of the cat?  Those are the topic of today's discussion.
On the cover of the August/September issue of the National Wildlife magazine, there was a picture of a drinking bobcat, its ears folded back in the posture that some refer to as "airplane ears."  On both of its ears were two white bars that made the ears look a lot like eyes.  I never really paid attention to this pattern on the coat, but once my friend Aidan Cook pointed it out, it got the proverbial gears going.  I remembered that servals also had the eyespot-like patterns as well, but did other cats?  Turns out a lot of them do, with just a few shared throughout the post.  Notice how defined the eyespot is in both the bobcat (top) and the serval, below.

To learn more, I consulted my "Wild Cats of the World" book by Mel and Fiona Sunquist.  The authors state that many cats have this pattern on their ears, "almost as many species" have the ear eyespots that are "poorly defined or absent."  One of the many examples that they include is the lion.  As you can see in the pictures below, lions do have this pattern to a certain degree, but nowhere near as derived as in the serval or the bobcat.  Below we have pictures of a young adult male lion, two of females, and one of a cub, and you can see that none of them have a very well defined eyespot.
Mountain lions also generally don't have it as well defined.  It seems like some mountain lions really don't have that much black on their ears at all, and some have a higher degree of black and white.  Presumably, whatever the function the eyespot serves in other species, it is not as important for the mountain lion, and natural selection therefore does not favor it highly one way or another.
It's a little tough to tell in the picture below, but the sand cat is another one of those cats that has a poorly defined eyespot.
Cheetahs also don't have terribly well defined eyespots.
Yet another cat that does not have very well defined eyespots, the ever fantastic Pallas cat!
I thought I had read somewhere that the eyespots served to help communicate between individuals when they were hunting.  This doesn't make that much sense, though, because most cats are solitary individuals, with the main exception being lions, and we already noted that their eyespots are not quite as specialized.  The Sunquists state in their book that the exact function of the eyespots is unknown, although some scientists believe that they serve as a "follow me" signal to their young, which "may be especially important in low-light conditions."  I assumed that this might mean that the young cats wouldn't have the eyespots, but this is clearly not true, as you can see the photograph of Sochi, the new male Amur leopard cub at the Denver Zoo.  There, you can see that Sochi (named after the Russian city that is holding this years Olympics) also has the ear spots.  So while this doesn't necessarily support the idea of a "follow me" signal to the young, it doesn't really not support it either: it's just something interesting that I wanted to point out.
We already talked about how tigers have a pretty well developed eyespot, but here are two more pictures of tigers to drive the point home.
I can't remember for certain if the picture below was a bobcat or a lynx, but I am pretty certain it is a bobcat, looking at the size of the feet.  (Lynx spend a lot more time in the snow, and therefore have larger feet, a snowshoe-like adaptation to keep them from sinking in.)  This cat, one of many at the Wild Animal Sanctuary, seems to have much smaller feet in proportion to the rest of the body.  Regardless, you can see the well defined eyespots.
The snow leopard, one of my favorite cats, has well defined eyespots as well, which you can kind of see in both of these pictures.
Photo Credit: Masaki Kleinkopf 
The fishing cat is another cat that has these well defined eyespots.
And finally, the Canadian lynx, much like its bobcat relative, also has pretty well defined eyespots!

Works Cited:

Sunquist, Mel, and Fiona Sunquist. Wild Cats of the World. Chicago: University of Chicago Press, 2002. (accessed January 20, 2014).

Tolmé, Paul. "Wildlife Feels the Heat." National Wildlife, August/September 2013.

1 comment:

  1. We visited a sanctuary yesterday and had a discussion about the eyespots. My friend who went with me is part of the zoo keeping family and said it was a way to blend in well hunting although to me they stand out more than blend in. It is hard to find anything on this topic and I've had to domesticated cats with eyespots not as defined but definitely there which got me curious. Thank you for the post !

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