All birds have a tongue just like Mammals but the tongue of a bird has a different use. While Mammals primarily us their tongue for tasting purposes , hence they have thousands of taste buds , the birds have a few hundred of taste buds only. The Birds eat their food by swallowing it as a whole and the food rests in the mouth only for a few seconds . The taste buds of the birds are very elementary in nature and are use only to detect any poisonous or unpalatable food that might make them sick.
So what do the birds use their tongues for ?
There are many different uses of tongue across different species and this also make the shape of tongue different.
Muscular Tongue :
Parrots have large Muscular tongues that help them hold and manipulate the seeds and nuts that they feed on. Same can be seen in Barbets and other frugivorous birds. This tongue dexterity also help the birds like Parrots to Mimic various voices.
“Piston Like ” Tongue :
Birds like Doves and Pigeons have a unique way of drinking water. They drink water directly like mammals and donot tilt their head backwards to push water in. This is because their tongue performs a piston like action to pump water inside their mouth.
This can also be seen in Flamingos where their beaks suck in lot of water with help of its thick tongue . Post filtering of water for their food using Lamallae , the small backward facing spines on the tongue will push the filtered food into the throat.
The remaining water is pushed out of the beak by the tongue. This is repeated as the flamingos feed on the Micro plankton in water.
Grooved Tongue :
This can be seen in Vultures and eagles espl that scavenge like the Steppe Eagle. When a kill is sighted a lot of different kinds of Vultures and scavenging birds arrive at the sight. There is a hierarchy they follow in terms of eating the carcass and each vulture species has a limited time to fill its stomach and then vacate the place . These birds fill their ” CROP” a special organ in their throat and also grab a mouthful and clawful before flying to a safe place and eat in peace. Here they regurgitate the food stored in crop and this is properly eaten in peace. But to fill the crop in limited time requires special skills and tools.
The grooved tongue of these birds help push the smooth, slippery fleshinto their throats at a faster speed . The beaks are not able to hold on to these slippery flesh and the tongue does this job efficiently. This helps to fill the crop quickly.
The Bearded Vulture that feed on bones uses its grooved tongue to suck out the bone Marrow from the broken bones that it drops on rocks.
Nectarine Tongues :
The Oriental White Eye has a thin tongue with Brush like tip to dab on the flowers and absorb the nectar, while the Sunbirds have a long tubular tongue with 2-3 branches ( Furcated) at the tip. This helps them suck in the Nectar.
Sticky Tongues :
The Woodpeckers, Tree creepers and other birds that grab their prey from Crevices and holes have a sticky barbed tongue. The woodpecker listens to the movement of insect and its larvae inside the tree trunks and then makes a hole , sticks its tongue in and the insect is stuck to the sticky barbed tongue.
Wood pecker also uses its tongue as a Cushion to protect its brain from damage when it pecks the tree surface ..( To know more on woodpeckers pls visit http://ogaclicks.com/wordpress/woodpecker-adaptation-ka-boss/)
Tongues of the young :
The tongue also plays an important role in the development of the chicks. The chicks have brightly coloured tongue that have spots and bars on them. These act as stimulants to the parents that feed the chick whenever its mouth is opened.
The chicks of the larger birds like Herons and storks push their beacks right into the mouth of the Parent. They hit a spot in the throat that makes the parent regurgitate the food into the young ones mouth.
Tongues are also use by birds to regulate their body temperature. Lot of birds can be seen with mouth open on perches during the day. The tongues are usually erect and exposed to the cool air so that the moist tongue can effectively do the evaporative cooing of blood supply in the mouth and face. Like The Bee-eaters
Thus the birds have adapted a part of their body in different ways compared to what the Mammals use it for. Looking at them I think there is hardly any organ that they don’t use and their levels of adaptations are the best in animal kingdom
Source : Wikipedia, Beat About the bush -Birds by Trevor Carnby
Photographs : Saravanan Janakarajan