What If Gone

Species → Kakapo

Kakapo

Strigops habroptilus

235 individuals (all individually named and tracked)
Extinction risk Critically Endangered
ConservationNear-extinctionUmbrella species
Kakapo (Strigops habroptilus)
Photo: Department of Conservation NZ, Wikimedia Commons (CC BY 2.0)

What if it disappeared?

Impact Moderate
Over 15 years

Introduced rats, stoats, and cats drove the kakapo down to just 51 individuals by 1995 — of the 12 chicks born in the preceding years on refuge islands, only 3 survived to adulthood.

Documented
Detail

Department of Conservation (Nouvelle-Zélande). History: Kākāpō Recovery.

Rats proved to be the main predator of newly hatched chicks, preventing enough young from being raised to offset adult mortality; stoats alone destroyed the Resolution Island population within six years of arriving, and cats caused the rapid decline of the Stewart Island/Rakiura population, forcing the complete evacuation of surviving birds to sanctuary islands between 1980 and 1997.

Hypothesized mechanism

The kakapo breeds at scale only in years when the rimu tree, its main food source, fruits abundantly — a synchronization researchers attribute to chemical compounds in the fruit that trigger egg-laying, though the exact mechanism remains unconfirmed.

Extrapolated
Detail

Fidler, A.E., Lawrence, S.B. et McNatty, K.P. (2008). An hypothesis to explain the linkage between kakapo (Strigops habroptilus) breeding and the mast fruiting of their food trees. Wildlife Research, 35(1), 1–7.

The authors propose that exposure to low doses of phytochemical compounds from rimu fruit, combined with a form of liver 'memory' in females, sensitizes egg-yolk protein genes to estrogens — ovarian follicles would only develop to ovulation in years when this pre-sensitization has occurred. This is an explicit mechanistic hypothesis, presented as such by its own authors, not a demonstrated fact.

What's missing to confirm it: Direct physiological confirmation of the proposed mechanism, rather than an observed correlation between rimu fruiting years and kakapo breeding years.

Breeding record

An exceptional rimu fruit harvest triggered the best breeding season on record: at least 95 chicks hatched in 2026, compared with 73 in the previous record year of 2019 — out of a total population of just 235 individuals.

Documented
Detail

Department of Conservation (Nouvelle-Zélande), rapporté par Mongabay (avril 2026).

A single exceptional breeding season can thus grow the population by dozens of individuals at once — but it depends entirely on a natural fruiting cycle that is unpredictable from year to year, one the recovery programme cannot trigger at will, only support once it happens.

Not measured to date

The kakapo is a nocturnal, ground-dwelling, browsing parrot, but no study measures what its presence or absence would change for vegetation or forest regeneration on the sanctuary islands where it now survives exclusively under intensive management.

Insufficient

Documentation

Last verified: August 14, 2026