22 September 2012

A GRASPING TONGUE


Above is a photomicrograph of a hummingbird's tongue (click to enlarge).  Like bees, hummers are nectivores, feeding on the sweet nectar of flowers.  In the process, they help to cross-pollinate between flowers, enhancing genetic variabillity.  Such a mutually beneficial arrangement is one example of a symbiotic relationship.

The two halves of a hummingbird's beak have a pronounced overlap, with the lower half (mandible) inside the upper half (maxilla).  When hummingbirds feed on nectar, the beak is usually only opened slightly, allowing the tongue to dart into the interior of flowers.

Here's what surprised me as I researched the surprising image above ~ though the long-held belief was that hummingbirds drink via capillary action, high-speed photography has revealed that the hummingbird's tongue's tubes open down their sides, and close around nectar.  This is as counter-intuitive as learning that when cats drink, they do not lap water up over the tongue and into the mouth.  Rather, cats form the tongue into an upside-down U, and lap water in beneath the tongue.

The world is full of wonders, waiting to be discovered.

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