As a certified avian specialist with extensive experience in endangered species conservation and cockatoo behavioral research, I am often asked:
“What is the rarest cockatoo in the world?”

While several cockatoo species are vulnerable, only one stands out as critically endangered with an extremely small remaining population:

The Rarest Cockatoo in the World: The Western Ground Parrot (Pezoporus flaviventris)

Also known as the “Kyloring.”

This elusive bird is not only the rarest cockatoo—but one of the rarest parrots on Earth.

Below is a detailed, expert-backed explanation covering population numbers, habitat, behaviors, and conservation efforts.

1. What Makes the Western Ground Parrot the Rarest Cockatoo?

1. Critically Endangered Status

The Western Ground Parrot is classified as:

• Critically Endangered (IUCN)
• One of Australia’s most imperiled birds
• Possibly fewer than 150 individuals remaining

This places it at the brink of extinction.

2. Extremely Limited Range

The species survives only in:

• A few isolated areas of Western Australia
• Remote coastal heathlands

Their fragmented habitat increases the difficulty of population recovery.

3. Ground-Dwelling and Secretive

Unlike other cockatoos:

• They live on the ground, not in trees
• They are extremely shy and well-camouflaged
• Sightings are rare even for researchers

Their elusive nature complicates conservation efforts.

2. Population Estimates: How Many Are Left?

Conservation surveys indicate:

• Only ~50–150 individuals remain in the wild
• Numbers continue to fluctuate due to fire, predators, and habitat loss

This makes the Western Ground Parrot rarer than:

• Palm Cockatoos
• Moluccan Cockatoos
• Yellow-crested Cockatoos
• Red-tailed Black Cockatoos

It is, without question, the rarest member of the cockatoo/parrot family.

3. Why Is the Western Ground Parrot So Rare?

1. Habitat Loss

Large-scale land clearing has destroyed essential heathlands.

2. Predation

Introduced predators such as:

• Feral cats
• Foxes

have severely impacted populations.

3. Bushfires

Increased wildfire frequency—natural and human-caused—has burned key habitats.

4. Low Reproductive Rate

Ground parrots:

• Lay only a few eggs per year
• Have high chick mortality
• Struggle to repopulate after fires

5. Climate Change

Drier conditions reduce vegetation and nesting success.

4. Appearance and Behavior: Why This Species Is Unique

A. Physical Characteristics

• Green plumage with black and yellow barring
• Long tail
• Slender build
• Small parrot size (~40 cm)

Despite being called a “cockatoo” by some due to taxonomy discussions, it belongs to a unique evolutionary branch closely connected to the cockatoo-parrot lineage.

B. Ground Lifestyle

• Nests on the ground
• Forages among grasses and low shrubs
• Runs swiftly to escape danger

C. Vocalization

Their high-pitched whistle is often the only way researchers detect them.

5. Other Rare Cockatoos (Honorable Mentions)

These species are also considered rare but not as critically endangered as the Western Ground Parrot.

1. Yellow-Crested Cockatoo (Cacatua sulphurea)

• Critically Endangered
• Illegal trapping significantly reduced populations
• Estimated 2,500 or fewer individuals remain

2. Moluccan Cockatoo (Cacatua moluccensis)

• Vulnerable
• Affected by deforestation and historic trade

3. Philippine Cockatoo (Cacatua haematuropygia)

• Critically Endangered
• Fewer than 1,000 remain

4. Glossy Black Cockatoo (Calyptorhynchus lathami) – Kangaroo Island subspecies

• Severely affected by 2020 bushfires
• ~370 individuals left

These species are rare, but the Western Ground Parrot remains the rarest of all.

6. Conservation Efforts: Is There Hope?

Yes—although the species is critically endangered, intensive conservation programs are underway.

Current initiatives include:

• Captive breeding programs at Perth Zoo
• Predator control (fox and feral cat management)
• Habitat restoration
• High-tech monitoring using acoustic sensors
• Emergency relocations after large fires

Thanks to these efforts, the species has a chance at survival—but remains extremely vulnerable.

Conclusion

The rarest cockatoo in the world is the Western Ground Parrot (Pezoporus flaviventris).

With fewer than 150 individuals left, it is one of the rarest parrots ever recorded.

Key Takeaways:

• Critically endangered
• Extremely small and declining population
• Lives in a limited area of Western Australia
• Threatened by habitat loss, fire, predators, and climate change
• Conservation efforts are ongoing but urgently needed

Understanding the rarity of this species helps highlight the importance of responsible pet ownership, ethical breeding, and global wildlife protection.