The National Zoological Park’s youngest brown kiwi (Apteryx mantelli), Areta (pronounced AH-reh-tah), died in the early morning of Feb. 14. She had not exhibited any warning signs of clinical illness. A full postmortem examination was conducted, and a final pathology report may provide more information in a few weeks.

Although she was not on exhibit in the Bird House, visitors to the Zoo’s website could watch Areta and Hiri, her older sister, forage in their nest box via the Zoo’s Kiwi Cam. Their parents are Māori (father) and Nessus (mother).

Areta was the second female brown kiwi to hatch at the Zoo, which has had success breeding these birds since 1975. The Zoo has contributed greatly to the Brown Kiwi Species Survival Plan; Māori and Nessus produced four chicks from February 2006 to June 2010. The two most recent hatchings—two females—marked a significant milestone for the species as well; currently there are only 14 female brown kiwi in zoos outside New Zealand, including eight in the United States.

In July 2010, the Zoo’s Smithsonian Conservation Biology Institute in Front Royal, Va., established a new kiwi breeding science center with the arrival of Tamatahi (ta-ma-TA-hee), a male, and Hinetu (hee-nay-TOO), a female. Both birds came from the Ngati Hine people in New Zealand and will be valuable breeders because their genes are not well-represented in the North American population.

Kiwi are native to New Zealand and have been there for more than 60 million years, making them New Zealand’s most ancient bird species. Brown kiwis are nocturnal, flightless birds whose adaptations more similarly resemble those of mammals than birds. They lay the second-largest eggs of all birds in relation to their body size. The International Union for Conservation of Nature lists the brown kiwi as an endangered species.