Kiwi are flightless birds endemic to New Zealand, in the genus Apteryx and family Apterygidea. Kiwis, shy, greyish brown nocturnal birds the size of a chicken are odd in many respects: the egg is, relative to the size of the bird, the largest of any living species; kiwi have a highly developed sense of smell and are the only birds with nostrils at the end of their long beak; the rudimentary wings are not evident exteriorly. The kiwi as a symbol first appeared in the late 19th century in New Zealand regimental badges. The kiwi has since become the most well-known national symbol for New Zealand. There are five recognised species- all of which are endangered.