Pallas’s squirrel is a tree-dwelling squirrel native from Taiwan and southern China through parts of Southeast Asia.
It has large eyes and strong claws on its fingers and toes. It grips branches and trunks as it moves through trees.
Formosan squirrels, also called Pallas’s squirrels, were introduced to Kanagawa, Japan, in the 1950s. Over 52 years they became established in fragmented suburban forests, and their mapped range reached 304 km². Researchers used seven years of capture–recapture data to estimate population parameters and study the expansion.
Because reproductive females hold exclusive home ranges, the researchers expected the females’ distribution to grow as their number increased. The observed expansion curve fit well with a model of exponential population growth. The Kanagawa records connect breeding-female numbers with the spread of an introduced squirrel population.
An extinction-risk assessment has not been added yet.
In Kanagawa, Formosan squirrels spread through fragmented suburban forests. Mapping where they occur and returning to the same areas can help local managers understand range expansion and plan responses.