Newsletter / Blog
2011-09-10 New Zealand’s national bird - Brown Kiwi or Kiwi – Apteryx australis
Brown Kiwi or Kiwi –Apteryx australis – is endemic to New
Zealand and is New Zealand’s national bird. It is New Zealand’s
most unique bird and it is also its most ancient.
The Kiwi is a
brown bird with unique feathers that have a hair like quality and is a
flightless bird with rudimentary wings and no tail. It is about the size of a domestic
chicken, kiwi is by far the smallest living member of the ratite family of
birds which include the Ostrich, Emu, Cassowary and the Rhea. It has a long
extended grey bill with nostrils at the end. It has four toes compared to the
other ratites which have two or three.
They are found on
both North and South Islands, Stewart, Little Barrier and Kapiti Islands.
The male bird
call is a “ah-el ah-el” uttered many times, while the female call is a louder,
hasher call “aarh aarh” or “ah-eh ah eh”. They start calling about 40 minutes
after sundown and are very vocal for up to two hours and will call
intermittently throughout the night.
Kiwi’s have a
highly developed sense of smell, unusual in a bird, and are the only birds with
nostrils at the end of their long grey beaks. They eat small invertebrates,
seeds, grubs, and many varieties of worms. They also may eat fruit, small
crayfish, eels and amphibians. Because their nostrils are located at the end of
their long beaks, Kiwi can locate insects and worms underground without
actually seeing or feeling them, due to their keen sense of smell.
During the mating
season, June to March, the pair call to each other at night, and meet in the
nesting burrow every three days. Once bonded, a male and female kiwi tend to
live their entire lives as a monogamous couple. These relationships may last
for up to 20 years. They are unique among other birds in that they have a
functioning pair of ovaries. Kiwi eggs can weigh up to one quarter the weight
of the female. Usually only one egg is laid per season. The kiwi lays the
biggest egg in proportion to its size of any bird in the world, so even though
the kiwi is about the size of a domestic chicken, it is able to lay eggs that
are about six times the size of a chicken's egg. The eggs are smooth in
texture, and are ivory or greenish white. The male incubates the egg, for a period
of between 63 to 92 days. Producing the huge egg places a lot of demands on the
female. For the thirty days it takes to grow the fully developed egg the female
must eat three times her normal amount of food. Two to three days before the
egg is laid there is little space left inside the female for her stomach and
she is forced to fast.
Introduced
mammalian predators, namely dogs, stoats, ferrets and cats are the number one
threat to kiwi. Other threats include habitat modification/loss and road
strike. The restricted distribution and small size of some kiwi populations
increases their vulnerability to inbreeding.
Conservation Status – Endangered. |