These Big, Fierce Birds Found Love in Australia—and Laid the First Southern Cassowary Eggs at the Adelaide Zoo in 34 Years

Zoo staffers don’t know whether the bright green eggs are viable and will ultimately hatch into chicks. However, the eggs themselves are a major win, because breeding the birds in captivity is tricky

Sarah Kuta | Daily Correspondent

October 23, 2026 11:42 a.m.

Finding love isn’t always easy—especially if you’re a southern cassowary, a massive, solitary bird with an aggressive reputation. But conservationists in Australia seem to have cracked the matchmaking code: A female cassowary recently laid two eggs after being paired with a potential mate.

The large, bright green orbs are the first southern cassowary eggs laid at Adelaide Zoo in South Australia in more than three decades—and their arrival is an encouraging bright spot for a species facing an uncertain future.

“This is really exciting news for us because it has been 34 years since we’ve had successful cassowary chicks here at Adelaide Zoo, so the team and myself included are very excited,” says Erin Kasteliz, team supervisor for birds at the zoo, in a statement.

Native to Australia, southern cassowaries are huge flightless birds found primarily in Queensland’s Wet Tropics and Cape York Peninsula; they also live in New Guinea and eastern Indonesia. Weighing up to 175 pounds and standing more than five feet tall, they’re the third-largest birds in the world, trailing behind emus and ostriches.

Beyond their imposing size, southern cassowaries are known for their striking appearance. Inky-black feathers cover most of their bodies, contrasting with vibrant blue necks, two dangling red wattles and a Mohawk-like casque—a raised, bony structure—atop their heads.

Southern cassowaries have been recorded eating more than 200 different kinds of plants, and they play an important role in maintaining rainforest diversity by dispersing seeds via their droppings. They’re mostly solitary creatures, but they aren’t afraid to use their powerful legs and sharp claws to defend their turf when necessary.

The International Union for Conservation of Nature considers southern cassowaries a species of least concern, but Australia lists them as endangered, with an estimated 4,400 individuals remaining on the continent. Their survival has been threatened primarily by habitat loss and fragmentation resulting from forest clearing for agriculture and infrastructure, but the species is also vulnerable to vehicle strikes, poaching, dog attacks and competition with feral pigs.

Some Australian zoos have captive populations, which are part of a breeding program managed by the Zoo Aquarium Association Australasia (ZAA). The organization maintains a studbook to help determine which birds should breed, with an overarching goal of maintaining genetic diversity.

Earlier this year, staff at the Adelaide Zoo got the go-ahead to try breeding their resident southern cassowaries: 10-year-old Martina and 13-year-old Jeffrey. Though the two birds seemed like a good match on paper, there was no guarantee sparks would fly when they met in person.

Chad Crittle, the zoo’s director, compared the team’s matchmaking efforts to online dating, where it “might look like everything lines up really well. We like the same things and you might like the same food, but when you actually meet, it doesn’t always work,” he tells the New York Times’ Jennifer Sinco Kelleher. “And the same can be for animals in a zoo setting as part of these programs.”

Fortunately, Martina and Jeffrey seemed to hit it off right away. When they were officially introduced in August, Jeffrey started preening Martina—and, later that same day, they copulated. After that, staff members saw them mating on "multiple occasions," Kasteliz says in the statement.

Bright Green Cassowary Egg Laid at Adelaide Zoo After 34 Years

This month, caretakers were overjoyed when they spotted two, fluorescent green eggs in the birds’ enclosure. And, they say, more could be on the way, as cassowary clutches typically contain three to five eggs. Whenever Martina is done laying eggs, it will be Jeffrey’s job to incubate them.

According to Kasteliz, the eggs’ neon-green color helps them blend in with their surroundings.

“That color comes from pigment in the shell and helps camouflage the egg," she says in the statement. "In the wild, cassowaries live in dense rainforest and will find a safe area amongst the leaves to lay, so that green helps keep the eggs hidden from predators.”

Zoo staffers don’t know whether the eggs are viable and will ultimately hatch into chicks. However, the sheer fact that Martina laid the eggs is a major win, since breeding southern cassowaries in captivity is so tricky. If the eggs do end up being viable, the zoo expects to have chicks in about 50 days—and Jeffrey would be responsible for rearing them.

For now, the team is cautiously optimistic. They’re keeping an eye on Jeffrey and Martina, while also trying to give them their space. They plan to be largely hands-off to let Jeffrey “have his first go at doing this so he can learn,” Crittle tells the Times.