House Mouse (Mus musculus)

Family: Muridae
Brief description: A mammal of the order Rodentia, it has a body between 6-11 cm in length, and the tail is between 6 and 9.5 cm long. Adults weigh between 12 and 24 g.
Biology and ecology: In what is believed to be its original native range- central Asia from south-western Russia to Iran – it is found in steppe and rocky areas. In the far wider range where it has been introduced by humans or followed them, it prefers inhabited areas or those heavily impacted by man, such as agricultural areas; nevertheless, it is often found in natural habitats as well. On islands, it tends to occupy all available habitats and can reach very high population densities, especially where rats Rattus ssp. are absent. Individual territories can vary greatly in size – from a few dozen square kilometres to 8 hectares - depending on habitat characteristics. House Mice have an extremely high reproductive potential: they achieve sexual maturity 8-10 weeks from birth, gestation lasts about 20 days, and a single female can give birth to a litter of 4-8 between 5 and 10 times a year.
Distribution and impact on biodiversity: Although its original native range was relatively small (the steppes of central Asia), the House Mouse is now one of the world’s most widespread mammals, having followed in man’s footsteps to colonize all continents and most oceanic islands. Its range expansion began several thousand years ago, and it is known to have occurred in ancient Egypt. While the impact of House Mice on island ecosystems is generally less significant than that of rats, it has recently been proven to harm countless species of plants and animals, so much as to impact the entire balance of the ecosystem, and to affect unexpectedly large vertebrates, such as albatross chicks weighing several kg, which are literally eaten alive by mice.