The kiwi bird, a national symbol of New Zealand, is facing increasing threats to its survival in the wild. Once widespread across New Zealand, kiwi populations have declined dramatically, with some subspecies now endangered. Understanding why the kiwi is at risk is key to protecting this iconic and unique bird.
What is a kiwi bird?
The kiwi is a flightless bird native to New Zealand. About the size of a domestic chicken, the kiwi has brown feathers, strong legs with no wings, and a long beak for probing the ground in search of food. Kiwi use their strong sense of smell to find prey like worms, insects, and other invertebrates in the soil and under brush.
There are five recognized species of kiwi:
| Species | Conservation Status |
|---|---|
| North Island Brown Kiwi | Endangered |
| Rowi | Endangered |
| Tokoeka | Vulnerable |
| Great Spotted Kiwi | Vulnerable |
| Little Spotted Kiwi | Vulnerable |
The kiwi is unique among birds for having nostrils at the tip of its long bill. The kiwi lays the largest egg relative to its body size of any bird species.
Why are kiwi populations declining?
Kiwi once ranged throughout both main islands of New Zealand, but habitats have diminished and populations have declined dramatically since human settlement. Several key factors put wild kiwi at risk:
Habitat loss
Deforestation by humans and browsing by invasive mammals have degraded and fragmented kiwi habitat. Kiwi require deep forest litter for foraging and nesting. With less old growth forest available, kiwi struggle to find suitable areas.
Predation
Kiwi chicks and eggs are very vulnerable to introduced predators like stoats, ferrets, cats, rats, and dogs. These mammals prey heavily on ground-nesting kiwi. Predation is the leading cause of mortality for young kiwi.
Long maturation
Kiwi take 3-5 years to reach sexual maturity. That long development combined with low hatching success limits reproductive rates. Stoats and similar mammals can kill adult kiwi too before they have passed on their genes.
Collision mortality
Being flightless, kiwi often fall victim to vehicle strikes when crossing roads. Mortality from vehicle collisions poses an additional threat.
How many kiwi are left in the wild?
The kiwi population is estimated to be around 68,000 total birds as of 2022. But some subspecies have seen stark declines:
| Species | Estimated wild population |
|---|---|
| North Island Brown Kiwi | 35,000 |
| Rowi | 400 |
| Tokoeka | 14,000 |
| Great Spotted Kiwi | 17,000 |
| Little Spotted Kiwi | 1,200-1,300 |
The Rowi subspecies has faced a dramatic decline to just a few hundred remaining in the wild. Other species have also seen their populations reduced and ranges contract. Without conservation efforts, kiwi may continue to decline.
Why save the kiwi?
Beyond national pride, saving the kiwi is important for ecological and evolutionary reasons:
Ecosystem role
As probes of the forest floor, kiwi help mix and aerate soil. Their foraging spreads seeds and spores that aid forest regeneration. Declining kiwi can impact soil ecology.
Evolutionary distinctness
Kiwi are in their own ancient genus _Apteryx_. Losing kiwi would mean losing a deeply unique branch of the avian evolutionary tree. Their survival preserves millions of years of evolution.
Umbrella species
The kiwi’s forest habitat houses many other native species. Protecting kiwi areas helps protect other flora and fauna too. By conserving kiwi, wider biodiversity benefits.
How can we protect kiwi?
Many conservation efforts are underway to protect wild kiwi populations:
Predator control
Traps, bait stations, and other methods to suppress invasive stoats, rats, ferrets, and cats in key habitat can reduce kiwi predation. For example, the Zero Invasive Predators program has removed predators from over 100,000 hectares of mainland New Zealand.
Captive breeding
Breeding programs at zoos and sanctuaries raise young kiwi in predator-free environments. These programs have helped supplement wild populations through careful release of sub-adults.
Habitat restoration
Local projects to restore native vegetation and expand protected areas create more usable kiwi habitat. Examples include community-led efforts to plant native tree corridors.
Road mitigation
Signage, reduced speed limits, and wildlife tunnels and culverts can reduce the risks of kiwi being hit on roads. Adjusting road layouts may also help steer kiwi away from traffic dangers.
Public education
Outreach campaigns remind people of steps they can take to protect kiwi, like keeping cats indoors, using predator-proof enclosures for small pets, and driving carefully in rural areas. Education bolsters conservation.
What is the future outlook for kiwi?
The kiwi still faces real threats, but its chance of survival is improving thanks to dedicated conservation:
Improved legal protections
All kiwi species are now protected under New Zealand’s Wildlife Act. This improves safeguards against overexploitation and habitat destruction. Stronger legal shielding benefits kiwi.
Expanded sanctuaries
More predator-free conservation zones are being established, like Zealandia sanctuary in Wellington. These protected areas allow kiwi populations to recover in safety. There are now at least 18 mainland kiwi sanctuaries.
Community stewardship
Initiatives like the Kiwis for Kiwi Trust engage the public in hands-on kiwi protection through activities like predator control, habitat restoration, and observation surveys. This community guardianship boosts kiwi outlooks.
Climate change impacts
Climate change may increase storm damage, fire risk, and pathogens that could stress kiwi. But conservation groups are working to enhance habitat connectivity and build kiwi resilience to looming changes.
Conclusion
The kiwi faces real threats from habitat loss, invasive species, vehicle strikes, and climate change. But robust conservation efforts focused on predator control, breeding programs, habitat restoration, road mitigation, community engagement, and climate resilience are helping protect the national icon. With active stewardship and expanding sanctuaries, the distinctive kiwi still has hope for the future. This flagship species anchors wider New Zealand conservation. Saving the kiwi means protecting New Zealand’s natural heritage.
