The San Diego Zoo’s Avian Propagation Center is caring for a Brown Kiwi chick for the first time in more than a decade. The female chick hatched from its egg March 11, and as is typical of this species, it didn’t eat for the first six days. The chick began eating and gaining weight, and on April 5, 2016, it weighed 11.8 ounces (333.6 grams).
It is typical for this bird species to lose weight for two weeks after it has hatched. San Diego Zoo animal care staff report the female chick lost 26 percent of her body weight before she began gaining weight the last week of March.
The Kiwi has several unique and unusual traits: it does not fly, the mothers do not feed their chicks, and the egg is four times the expected size for a bird of the Kiwi’s proportions.
Animal care staff will continue to monitor the Brown Kiwi chick, measuring its weight and observing the young bird in a brooder over the next several weeks.
The San Diego Zoo successfully reared its first Brown Kiwi in 1983, and the recent hatching marks the Zoo’s 11th chick. The San Diego Zoo is one of just six zoos in the United States working with these endangered birds.
The North Island Brown Kiwi (Apteryx mantelli; Apteryx australis or Apteryx bulleri) is a species of Kiwi that is widespread in the northern two-thirds of the North Island of New Zealand and, with about 35,000 remaining, is the most common Kiwi. This bird holds the world record for laying the largest eggs relative to its body size.
Females stand about 40 cm (16 in) high and weigh about 2.8 kg (6.2 lb). Males weigh about 2.2 kg (4.9 lb). Their plumage is streaky red-brown and spiky. The North Island Brown Kiwi is the only species of Kiwi found internationally in zoos.
They feed on invertebrates. They have two-three clutches a year with two eggs in each clutch. Chicks are fully feathered at hatching and leave the nest and can fend for themselves within one week.
The North Island Brown Kiwi is classified as “Endangered” on the IUCN Red List of Threatened Species. Their major threats come from predators, such as dogs, cats, and stoat Mustela erminea.
Nationwide studies show that, on average, only five percent of Kiwi chicks survive to adulthood. However, in areas under active pest management, survival rates for North Island Brown Kiwi can be far higher.
Bringing species back from the brink of extinction is the goal of San Diego Zoo Global. As a leader in conservation, the work of San Diego Zoo Global includes on-site wildlife conservation efforts (representing both plants and animals) at the San Diego Zoo, San Diego Zoo Safari Park, and San Diego Zoo Institute for Conservation Research, as well as international field programs on six continents. The important conservation and science work of these entities is made possible by the San Diego Zoo Global Wildlife Conservancy and is supported in part by the Foundation of San Diego Zoo Global.