At Adelaide Zoo, in full view of the staff, a clutch of bright green, almost fluorescent eggs appeared — the first in 34 years. A ten-year-old female southern cassowary named Martina laid the eggs after a carefully planned introduction to a thirteen-year-old male named Geoffrey. The event was an unexpected victory in a long history of attempts to breed these rare birds in captivity.
Southern cassowaries are large, solitary and sometimes aggressive birds that live in the rainforests of Australia and New Guinea. About four and a half thousand individuals remain in the wild, and the main threat is habitat loss due to logging, roads and dog attacks. Breeding these birds in zoos is especially difficult: males and females usually keep apart and show tolerance toward each other only during the breeding season. Zoo staff spent months observing the pair's behavior — listening to their low "boom" calls and watching them eat near each other by the mesh — before bringing them together in August.
The introduction went well: Geoffrey first approached cautiously, then began preening Martina's feathers, and they mated that same day. Mating has continued since then. Martina may now lay another two or three eggs — the usual clutch size is three to five. The green color of the shell, caused by the pigment biliverdin, serves as natural camouflage among the foliage of the tropical forest. At the zoo the eggs lie at the very front of the enclosure, so the keepers added extra fabric for privacy.
The male will take on incubation — by the tradition of the species, it is he who sits on the eggs for about fifty days and then raises the chicks. It is not yet known whether the eggs are fertilized, and the appearance of chicks cannot be guaranteed. The last successful hatching in Adelaide was in 1992, and the first chick hatched back in 1968. For the breeding program run by the Australasian Zoo Association, every such clutch is an important step toward preserving genetic diversity.
Cassowaries play a key role in the ecosystem: they disperse the seeds of hundreds of plant species, fertilizing the soil with their droppings. Their disappearance from the forests would mean the loss not only of a magnificent bird but also of an entire mechanism for renewing tropical biodiversity. Zoo programs will not replace the wild, but they offer the species a chance at survival while the struggle to conserve its habitats continues.
The success of Martina and Geoffrey shows how delicate and patient work with solitary, demanding animals must be: the right moment, attentive observation and a willingness to give the birds space.
