The Columbus Zoo and Aquarium has achieved another significant first with the successful hatching of a North Island Brown Kiwi (Apteryx mantelli) on Mar. 23, 2011. The Columbus Zoo is only the third zoo in North America to successfully hatch a Kiwi chick since the first one hatched at Smithsonian’s National Zoo in 1975 and this chick is only the fifth kiwi to successfully hatch in as many years.
“The fact this egg successfully hatched is a testament to the amazing care and attention given by our staff in consultation with professional colleagues around the world” said Columbus Zoo and Aquarium President and CEO Dale Schmidt. “Like an expectant parent, kiwi expert Kathy Brader from Smithsonian’s National Zoo rushed to Central Ohio to be here and assist our team with the newly hatched chick.”
At the Zoo eggs are checked to see if they are fertile 30-45 days after they are laid. To maximize the potential of a successful hatching a fertile egg is placed in an incubator where it is monitored for temperature and humidity and turned slightly each day. Once the chick pips the egg it takes about four days for it to completely emerge and it survives on its yolk sac for 6-12 days.
Kiwi chicks are miniature versions of the adult kiwi and are about 1/8 of the size of an adult when they hatch. They are precocial, meaning they are completely on their own after hatching, and must find food and avoid predators without assistance. Most birds locate their food through sight and have a relatively poor sense of smell. Being nocturnal, the kiwi’s senses are just the opposite and they use their long beak to forage through leaf litter sniffing out earthworms and other invertebrates, fruits and berries.
Kiwis have a high mortality rate in the wild mostly due to predation by invasive species; 50% of kiwi eggs fail to hatch, 90% of chicks do not survive to six months of age and only 5% reach adulthood. Kiwi males are sexually mature at two years of age and females are reproductive at about three years old.
The five distinct species of kiwi are only found in New Zealand and zoos outside of New Zealand only manage the North Island brown kiwi. The kiwi is the unofficial mascot of New Zealand and despite having legal protection since 1896 their numbers are declining mostly due to predation by non-native species including dogs and cats.
The Columbus Zoo’s conservation program has supported projects to protect the kiwi including supplying funds to construct predator proof fencing around reserves and fitting kiwis with transmitters to enable regular monitoring.
The sex of the chick is determined through DNA testing and not known at this time. In addition to this chick, which is currently not on display, there are three other kiwi at the Columbus Zoo and Aquarium. There are now just 20 kiwis in three United States zoos.