Bat whose giant tongue outslurps all rivals

The Times
December 07, 2006

A recently discovered species of bat has leapt into the record books on account of its having the longest mammalian tongue proportionate to body size.

The tube-lipped nectar bat’s tongue is so long that the creature has to store it in its ribcage when taking a break from using it to sup from flowers.

Relative to body size, the tongue of the tube-lipped nectar bat, Anoura fistulata, is longer than that of any other vertebrate except the chameleon. If cats’ tongues were of the same proportion they could lap milk from a bowl two feet away.

The tongues can stretch 50 per cent longer than the animal’s two-inch body length.

Tube-lipped nectar bats use their extra-long tongues to reach nectar in long-necked flowers. They have a close relationship with the flower Centropogon nigricans, because they are the only species of bat able to reach far enough to obtain the plant’s nectar. This high degree of specialisation has given rise to the belief that the flower and the bat co-evolved, with the plant dependent on the bat for pollination.

Two other nectar-drinking bats are found in the same tropical forest area of the Andes in Ecuador, but neither is able to reach far enough into the tube-shaped flower. Samples were taken from the three types of bat, and pollen from Centropogon nigricans was found only on the tube-lipped species.

The study, reported in the journal Nature, observed that the bat’s tongue was so long that the animal had developed an unusual storage technique. “In other nectar bats, the base of the tongue coincides with the base of the oral cavity [the typical condition for animals], but in A fistulata the tongue passes back through the neck and into the thoric cavity,” the report said.

The tube-lipped species is one of a number of nectar-drinking bats, and hundreds of plants rely on them for pollination, but this is the first example of a flower that depends solely on one type of bat.

The report noted that the bat “can extend its tongue twice as far as those of related bats”, and that the flower length exactly matches the reach of the bat’s tongue.

http://www.timesonline.co.uk/article/0,,11069-2490305,00.html