The house mouse, Mus musculus, is now one of the most widespread mammals globally, inhabiting nearly every continent alongside human settlements. While this small rodent is a familiar presence worldwide, it is not native to most places it currently occupies. The species successfully colonized the globe by forming a close association with human civilization. This article clarifies the house mouse’s specific native range and explains the historical process that led to its ubiquitous distribution.
The Ancient Homeland of the House Mouse
The ancestral origin of the house mouse is genetically traced back to Southwestern Asia, specifically the Iranian plateau and northern India, near the Himalayas-India-Pakistan junction. Genomic evidence suggests this vast area served as the center for the species’ evolutionary divergence approximately 333,000 to 134,000 years ago.
This early divergence resulted in three primary subspecies that spread across the Old World:
- The Southeastern Asian house mouse (Mus musculus castaneus) is native to southern and southeastern Asia, including the Indian subcontinent.
- The Eastern European house mouse (Mus musculus musculus) spread across northern Eurasia, including Siberia and Eastern Europe.
- The Western European house mouse (Mus musculus domesticus) established itself across the Middle East, North Africa, and Western Europe.
Historical Migration and Global Colonization
The global dispersal of the house mouse was directly dependent on the movement of human populations. The mice transitioned to a commensal existence, living in close association with people and benefiting from their activities. This behavioral shift allowed them to exploit human resources, such as stored grains and shelter.
The first major expansion began approximately 10,000 years ago, following the spread of early agriculture out of the Fertile Crescent and the Middle East. Neolithic farming settlements provided a continuous supply of food and reliable shelter, enabling the house mouse to expand rapidly across Eurasia. By the Iron Age, around 3,000 years ago, the Western European subspecies was established across Europe.
Maritime trade and exploration accelerated the colonization of distant lands. House mice traveled as stowaways on Viking ships as early as the 10th century, reaching North Atlantic islands like Iceland and Greenland. They were carried to the Americas, Australia, and Oceania with European migrants during the Age of Exploration. This ability to hitch rides with humans transformed the regional species into a globally distributed one, making it an introduced species on every continent except Antarctica.
Distinguishing Regional Native Rodents
In regions outside of Eurasia, such as North America and Australia, the house mouse is an immigrant that often coexists with small native rodents. Readers frequently confuse the invasive Mus musculus with these local species, which evolved independently. In North America, for instance, the most common native species is the Deer Mouse (Peromyscus maniculatus).
The Deer Mouse and the related White-footed Mouse are native to North America and belong to a different biological family. Unlike the House Mouse, which prefers human dwellings, these native species primarily inhabit outdoor environments like forests and fields. In Australia, the house mouse is often mistaken for marsupial species like the Antechinus or rodents like the Spinifex hopping mouse. Australian natives, such as the Antechinus, are distinguishable by features like a pointier snout, which contrasts with the House Mouse’s rounder head.