Nest Boxes Offer Hope for Endangered Yellow-Crested Cockatoos in Urban Hong Kong

Published Time: 09-18-2025, 15:45 EDT

Hong Kong’s skyline may be dominated by skyscrapers, but in its urban parks a rare and endangered species—the yellow-crested cockatoo—has found an unlikely refuge. These snow-white parrots, easily recognized by their golden crests, are critically endangered, and conservationists are now stepping in to help them overcome a housing crisis of their own: a lack of nesting spaces.

New research shows that while Hong Kong is home to a significant share of the global population, the birds face major survival challenges. A project to install artificial nest boxes is giving them a better chance to breed, sustain their numbers, and perhaps even contribute to global conservation.

A Species Struggling to Survive

The yellow-crested cockatoo (Cacatua sulphurea) is native to Indonesia and East Timor, where wild populations have collapsed. According to the International Union for Conservation of Nature (IUCN), as much as 90% of the population has disappeared since 1978, primarily due to poaching for the illegal pet trade.

Today, fewer than 2,000 mature individuals are estimated to remain in the wild. Hong Kong’s population—around 200 birds—represents roughly 10% of the global total.

Despite their resilience in adapting to the city’s parks and neighborhoods, their numbers in Hong Kong have stagnated. The birds nest in tree cavities, but typhoon damage, aging trees, and government trimming for public safety have left them with fewer suitable homes.

Nest Boxes: A Conservation Solution

In response, conservationists are installing artificial nest boxes designed to mimic the natural hollows the birds prefer.

Astrid Andersson, a postdoctoral researcher at the University of Hong Kong, has led the initiative. She confirmed that a pair of cockatoos had already settled into one of the first boxes installed on the university’s campus.

Her goal is to have at least 10 boxes in place by the end of this year and expand the project to 50 across Hong Kong Island in the coming years.

“And then they can continue to live in the city,” Andersson said.

The nest boxes are filled with wood chips and carefully placed in trees across urban parks. Conservationists hope that, combined with ongoing monitoring, they will provide the safe breeding sites these cockatoos desperately need.

Global Threats in Indonesia

While Hong Kong’s population is stable, the species’ survival in its native range is far more precarious. Once common across Indonesia’s islands, the cockatoo has disappeared from most of them.

The pet trade remains a serious threat. Despite a 1994 export ban in Indonesia, weak enforcement has allowed illegal trafficking to persist. In 2015, police arrested a man for attempting to smuggle 20 cockatoos stuffed into plastic water bottles.

Deforestation adds another layer of risk. Data from Global Forest Watch shows that Indonesia lost 107,000 square kilometers (41,300 square miles) of rainforest between 2002 and 2024—roughly the size of Iceland. Climate change compounds these threats, drying forests and fueling fires triggered by volcanic eruptions.

“The fires are humongous,” said Bonnie Zimmermann, director of the Indonesian Parrot Project, a nonprofit focused on parrot conservation.

The Role of Hong Kong’s Bird Market

Hong Kong’s wild cockatoos may have unusual origins. Some researchers suggest they descend from pets released during World War II, while others believe they are escapees from the local pet trade.

Although the city bans the sale of wild-caught cockatoos, it permits trade in captive-bred birds registered under CITES (the Convention on International Trade in Endangered Species). However, no such breeding operations exist in Hong Kong.

A 2017–2018 survey led by Andersson found 33 cockatoos for sale in local markets, three times higher than official import figures since 2005. This suggests that some birds may have been trafficked or bred locally without proper oversight.

One Hong Kong resident, Dreamy Cheung, said she unknowingly purchased a yellow-crested cockatoo in 2021 for 20,000 Hong Kong dollars ($2,570). After learning of the species’ endangered status, she expressed concern about her pet’s origins.

“It’s like taking away someone else’s baby,” Cheung said.

To address these concerns, Andersson has developed a forensic DNA test to differentiate wild cockatoos from captive-bred individuals, a tool she hopes will eventually be used in local markets.

Government Response

In a statement to the Associated Press, Hong Kong’s Agriculture, Fisheries and Conservation Department said it conducts regular inspections of bird markets and remains committed to protecting endangered species. The agency reported no confirmed cases of cockatoo poaching in the past five years but pledged to investigate any reports.

It also noted that it advises on bird conservation during tree trimming operations, which can affect nesting habitats.

Coexistence in a Dense City

Conservationists say Hong Kong’s cockatoos demonstrate how endangered species can survive alongside people in heavily urbanized environments.

Some scientists even suggest that the city’s population may hold unique genetic traits absent in their original habitats, potentially playing a role in the species’ long-term survival.

Andersson’s team is now installing cameras inside nest boxes to study cockatoo reproductive behavior, which remains poorly understood.

Harry Wong, a conservationist who attempted a similar nest box project a decade ago without success, expressed optimism after seeing cockatoos quickly occupy the new boxes at the University of Hong Kong.

“We can create small things in the city that allow the animals who live here to coexist with us,” Wong said.

A Future for the Yellow-Crested Cockatoo

While challenges remain, the project signals hope that Hong Kong’s cockatoos could make a meaningful contribution to global conservation. By creating safe nesting spaces and addressing illegal trade, scientists and conservationists are working to ensure these striking birds will not vanish from the city’s parks—or the planet.

As urban residents continue to hear the cockatoos’ squawks echo through Hong Kong’s green spaces, the survival of this critically endangered species may depend on both scientific innovation and public awareness.