The question of “what animals eat kiwi” involves two distinct subjects: the native, flightless bird of New Zealand and the fuzzy, commercially grown fruit. The kiwi bird (Apteryx species) is an ancient avian species that evolved without ground-dwelling mammalian predators. This lack of evolutionary defense mechanisms makes the bird acutely susceptible to introduced threats. Conservation efforts focus on mitigating the impact of these non-native predators on the bird’s survival.
The Major Mammalian Predators of Kiwi Birds
The survival of the kiwi bird population is threatened by mammalian predators introduced to New Zealand following human settlement. These non-native species cause the vast majority of kiwi deaths. Four species—stoats, feral cats, ferrets, and domestic dogs—account for nearly all predation events, taking advantage of the kiwi’s ground-dwelling, nocturnal lifestyle.
Stoats (Mustela erminea) are the most damaging predator overall. These small hunters were introduced in the late 1800s to control rabbits but quickly turned to defenseless prey. They are adept at locating and killing kiwi chicks, even those several times their own weight. Feral cats, which are widespread, also contribute significantly to the predation of young and smaller kiwi.
Ferrets (Mustela putorius furo), the largest mustelid in New Zealand, and domestic dogs (Canis familiaris) pose the primary threat to adult kiwi birds. Ferrets prey on adults, and population increases, often linked to rabbit numbers, can severely affect breeding populations.
Uncontrolled domestic dogs are the most frequent cause of death for adult kiwi, often reducing the average lifespan from over 60 years to less than 15 years in some areas. The kiwi lacks a bony sternum to protect its large internal organs, meaning even a playful nudge or bite from a dog can be fatal.
Predation Risk by Life Stage
The vulnerability of a kiwi bird changes dramatically as it matures, which is a key consideration for conservation strategies. Kiwi chicks are disadvantaged due to their size and inability to defend themselves. This results in a survival rate of only about five percent to adulthood in areas without active predator control. The primary killers of these young birds are smaller mustelids and feral cats.
A chick remains highly vulnerable to stoats until it reaches a body weight of approximately 1 to 1.2 kilograms. At this weight, it is large enough to fight off or deter the smaller predator. Because the early months are high risk, conservation programs often use techniques like “Operation Nest Egg.” Eggs are hatched in predator-free facilities, and sub-adults are released only after they reach a protective weight. Once a kiwi reaches adulthood, its size and powerful legs allow it to defend itself against stoats and cats.
However, the adult bird’s size does not protect it from larger predators, particularly dogs and ferrets. The force and size of these animals overwhelm the adult kiwi’s defenses, leading to a high mortality rate among the breeding population. Predator control must be multi-faceted, targeting smaller species to save chicks and controlling dogs and ferrets to protect the long-lived adults.
Animals That Consume Kiwi Fruit
The kiwifruit (Actinidia deliciosa) originated in China and is now cultivated globally, where it faces agricultural pests. Animals that consume the fruit are typically classified as pests by commercial growers, causing economic damage to the harvest. These include insects and generalist mammals attracted to the fruit’s sweetness and soft interior.
Various insect species cause direct damage to the fruit, particularly the larvae of moths known as leafrollers, which feed on the fruit’s surface and foliage. Other insect pests include armored scale insects and mealybugs, which attach to the fruit and vines to feed. Mammalian pests, such as deer browsing on leaves or rodents attacking roots, can also damage the plants even if they do not consume the fruit directly.
In cultivated settings, generalist feeders like rats and possums may eat the fruit. However, the most problematic pests often cause blemishes or structural damage that reduces the fruit’s commercial value. Managing these animals requires specific integrated pest management strategies.