The birds are native to Indonesia. The zoo studied and recreated the special conditions they need to successfully incubate.
What do they look like? Zoo curator Nancy Clum describes them on a YouTube video posted by the Wildlife Conservation Society.
To her, a maleo resembles a chicken with a fan tail, a pink belly - and a football helmet on the back of its head.
A maleo shown in a close-up also has an orange beak and big brown eyes ringed with orange and yellow.