Page 209 - Atlas Of The World's Strangest Animals

NARWAL 209

The ice here is thinner. If she uses her cushioned forehead like Success! The female takes a much-needed breath. By returning
a battering ram, she may break through. to the hole regularly, she’ll keep it open for others to use.

The English naturalist Charles Darwin (1809–1882) Then, in 2005, Harvard School of Dental Medicine
believed that the narwhals’ tusks were a sexually selected researcher Martin Nweeia made a surprising discovery.
characteristic. Darwin is famous for his Theory of Working with Frederick Eichmiller at the National
Evolution, which he proposed in his 1859 publication On Institute of Standards and Technology and James Mead of
the Origin of Species. In it, he notes that many species the National Museum of Natural History of the
develop unusual physical characteristics, which have no Smithsonian Institution, he examined a narwhal tusk
obvious practical use but which them to attract a mate. through an electron microscope. It was seen to contain
Lion’s manes and peacock’s tails are other examples of millions of nerve endings, which radiated out from the
‘secondary sexual characteristics’.The ritual of tusking, core.This led them to suggest that the tusk is a unique
when male narwhals’ rub each other’s tusks up, seemed to sensory organ, capable of detecting changes in water
support this view.Tusking is not a matter of fighting – and temperature and pressure. It may also be able to pick up
narwhals have rarely been seen to fight – but rather it seems changes in the salinity of the water and particles associated
to be the method by which males establish rank. with prey – all of which are vital to the narwhals’ survival.

Comparisons

Narwhals share their chilly Arctic waters with a close relative –the their own, equally odd, claim to fame.They have been nicknamed
beluga whale (Delphinapterus leucas). Although both species have a ‘sea canaries’ on account of the high-pitched squeaks, squeals and
similar shape and grow to a comparable size, belugas are famously whistles that they produce
snowy white in colour.While narwhals have horns, beluga have

Narwhal Beluga

(c) 2011 Marshall Cavendish. All Rights Reserved.