<P> Kiwi are shy and usually nocturnal . Their mostly nocturnal habits may be a result of habitat intrusion by predators, including humans . In areas of New Zealand where introduced predators have been removed, such as sanctuaries, kiwi are often seen in daylight . They prefer subtropical and temperate podocarp and beech forests, but they are being forced to adapt to different habitat, such as sub-alpine scrub, tussock grassland, and the mountains . Kiwi have a highly developed sense of smell, unusual in a bird, and are the only birds with nostrils at the end of their long beaks . Kiwi 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 using their keen sense of smell, without actually seeing or feeling them . </P> <P> Once bonded, a male and female kiwi tend to live their entire lives as a monogamous couple . During the mating season, June to March, the pair call to each other at night, and meet in the nesting burrow every three days . These relationships may last for up to 20 years . They are unusual among other birds in that, along with some raptors, they have a functioning pair of ovaries . (In most birds and in platypuses, the right ovary never matures, so that only the left is functional .) 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, except for the great spotted kiwi, A. haastii, in which both parents are involved . The incubation period is 63--92 days . Producing the huge egg places significant physiological stress 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 . </P> <P> Lice in the genus Apterygon and in the subgenus Rallicola (Aptericola) are exclusively ectoparasites of kiwi species . </P> <Table> <Tr> <Td> </Td> <Td> This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . (September 2013) (Learn how and when to remove this template message) </Td> </Tr> </Table>

The greatest threat to the endangered great spotted kiwi of new zealand is introduced predators