Wednesday, September 17, 2014

The Hummingbird Tongue

If you didn't know any better, you would think a hummingbird had a tubular bill with a hole in the end of it for sucking up nectar. That would appear to be true from observing them, but those would be completely false conclusions. Their bills are divided - and this may be surprising because it is not commonly seen - into upper and lower parts like most other birds. There is no hole in the beak through which their tongue can pass nor do they suck up nectar like sucking on a straw.

Instead, they lap nectar like a dog would lap water. Their tongue is controlled by a very long muscle which extends around the lower part of their jaw and up the back of their skull. This allows them to extend their tongue beyond the bill almost as far as their bill is long

I saw a little comedy on the river one morning that had me laughing. Trumpet flowers, with their long, tubular orange blossoms are common on the shore of the river. It is not unusual to see hummingbirds stopping to sample the nectar. I don't know that I had ever watched one sampling these flowers, but one that was very close caught my eye one morning.

The tubular portion of a trumpet flower is so long that, even with it's extremely long tongue, the hummingbird couldn't reach the interior of the bloom where the nectar was residing. So, it was having to dive into the flower and push in as far as it could.  Once it did, another problem was created because the bird was unable to use it's wings in the tight quarters and the weight of the bird caused the flower to descend several inches like a down elevator. The blossom would dump the bird out and the flower would return to it's previous position, and the bird would start over again.

Another feature about a hummingbird tongue is that it has structures on the side that hold the liquid. When they are drinking at a feeder, they are actually lapping nectar at several times a second. Tiny grooves on the tongue allow the bird to take advantage of capillary action and easily drink the fluid.

Finally, the tongue is split and divided to about half it's length, but this is hardly ever visible. Who knew this small bird could have a tongue with so many unusual features? Since it is so integral to it's survival, maybe it is not all that surprising.

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