New Zealand is globally recognized for its unique biodiversity, a result of millions of years of ecological isolation that fostered an environment dominated by birds and insects rather than terrestrial mammals. This distinctive natural history makes the country’s mammalian fauna particularly sensitive to outside influence, a lesson learned through the introduction of various pests in the 19th century. Understanding the country’s ecological profile provides the context for questions about species like squirrels, which are widespread across continents but noticeably absent in the New Zealand wilderness.
The Definitive Answer: No Established Squirrels
The simple answer is that no established wild populations of true squirrels, belonging to the family Sciuridae, exist anywhere in New Zealand. This includes the common tree squirrels, ground squirrels, and flying squirrels found throughout North America and Eurasia. “Established” means a self-sustaining, free-ranging population that breeds successfully without human intervention. Historical attempts to introduce various exotic species never resulted in a permanent, successful colony.
History of Failed Introductions and Strict Biosecurity
The current absence of squirrels is not due to a lack of effort during New Zealand’s 19th-century “acclimatisation” period, when many non-native species were introduced, often with disastrous results. Any minor attempts made during this era failed to establish a viable population, possibly due to a lack of suitable habitat, insufficient founder numbers, or swift eradication. The country’s natural environment, previously lacking native land mammals other than bats, proved highly susceptible to invasive species like the brushtail possum and various mustelids.
Learning from this devastating impact, New Zealand implemented some of the world’s strictest conservation policies. The legal framework, enforced under the Biosecurity Act 1993, classifies all squirrel species, such as the American Grey Squirrel (Sciurus carolinensis), as “unwanted organisms.” This classification is based on the potential harm they could inflict on native forests and agriculture, particularly through bark stripping and seed predation. The Ministry for Primary Industries (MPI) maintains rigorous border controls to prevent the entry of any squirrel species, and any sighting of a wild animal triggers an immediate eradication response.
The Eastern Chipmunk: A Small Distinction
While true tree squirrels are absent, a single, highly localized population of a close relative, the Eastern Chipmunk (Tamias striatus), is sometimes cited as an exception. The chipmunk is a member of the squirrel family (Sciuridae) but is a distinct genus. This tiny, isolated group is confined to a small area in the South Island, specifically near Lake Wanaka, originating from a private introduction that persisted.
Chipmunks are physically and ecologically different from the larger arboreal squirrels. The Eastern Chipmunk is a small, striped rodent, typically weighing between 66 and 150 grams, and is primarily a ground-dwelling species that uses its cheek pouches to carry food back to underground burrows. Unlike the larger tree squirrels, the chipmunk’s ecological impact remains minimal and highly localized to its contained range in the Otago region.