A Birds-Eye View

There are a lot of sayings about eyes.  When I 'googled' it, I found a list of 432 quotes having something to do with eyes--

Eyes are the windows to the soul.  Bright-eyed and bushy-tailed.  Beauty is in the eye of the beholder.  A sight for sore eyes.  

(I could go on... according to the list there are 428 more!)  Obviously, eyes are important.  When we think of birds though, we are more apt to think of their beautiful feathers and pretty songs than their eyes.  But birds eyes are interesting... let's take a look at some of them.

Here's a male Cardinal - of course we notice his red feathers, but if we look with 'eagle eyes' we'd see more details.

How about a Chickadee? Doesn't it look 'bright-eyed'? (not bushy-tailed though!)

Some birds are named for their eyes.  Here's a Red-eyed Vireo:

While it's pretty easy to see why that vireo would be called Red-eyed to distinguish it from the 13 other vireos listed in my Sibleys Field Guide to Birds of Eastern North America, I wondered about another bird named for their eyes --  Dark-eyed Juncos.  Yes, their eyes are dark-- but so are many other birds.  So I looked up Juncos, and found out there is a Yellow-eyed Junco (they mostly live in Mexico so I don't have a photo but you can see one by clicking here) and it made sense!

We do have some yellow-eyed birds here though, such as Grackles and Rusty Blackbirds.

Just like human eyes, some birds' eyes change color as they age.  Notice the young Grackle on the left - its eye is not yellow like the parent on the right.  Of course it's feathers are a lot different, too.

Other birds eyes change color as they get older as well.  Red-bellied woodpeckers eyes are more brownish when they are young and get redder with age.

This Killdeer parent has red eyes, too.

We can't see the baby Killdeer's eyes in that photo because it's so well hidden underneath its mommy.  'What the eye doesn't see the heart doesn't grieve over' (the baby isn't scared of the lady with the camera if it can't see me!)

Someday it will grow up and be able to 'keep an eye on the sky' like this:

Scientists know quite a bit about the anatomy of birds eyes.  They know that birds have 3 types of photoreceptors (rods, cones, and double cones) while humans have only the first two kinds.  So birds may see colors better than we do.  While scientists know this, of course they can't be sure exactly what birds see.  It is thought that they may even be able to see ultraviolet light!  

I wonder how this male Indigo Bunting would look to a female Indigo Bunting?  He might be some real 'eye candy' and turn out to be the 'apple of her eye".

Birds eyes are larger than our eyes relative to the total area of our heads, which is another advantage.  That probably allows them to see better than we do, too.  A starlings eye is 15% of its head mass while the average humans is less than 2%.  The cone cells in a humans retina number about 200,000 per square millimeter, while a sparrow has 2 times that many and a hawk has 5 times!  Hawks can see details at distances 2 to 3 times further away than us.  So if you say someone has 'eyes like a hawk' that is a really good thing.

Birds have some advantages over humans in sight, but we have something they might 'give their eye teeth for' (if they had teeth).  That's the fact that we can move our eyes around in our heads and they can't.  To make up for it, they can move their heads quite a lot.  Of course we think of Owls, which have the most head-turning ability, but most birds have a fair amount -- like this Northern Flicker:

This time of year, we mostly have to get our bird-fix by watching the birds at our feeders.  So I've been 'keeping one eye' on the windows.  When I saw this Evening Grosbeak, I almost 'could not believe my eyes'. 

Of course, Blue Jays are quite common in comparison.  Though there is more to them than 'meets the eye' when you see the intricacy of their facial feathers!

Though our birds eat a lot, I'll keep putting seeds and suet out for them.  Sometimes 'their eyes are bigger than their stomachs' - like the Titmouse with this chunk of suet.

The price of bird food is worth it because the birds are 'a sight for sore eyes', especially this time of year.