e. Polynesian Rat. The Polynesian rat accompanied Polynesians and
Micronesian voyagers from Southeast Asia as a self-replenishing source of food. It is
found in Hawaii.
f. Lesser Bandicoot. The lesser bandicoot, scourge of Southern Asia, gorges
in grainfields and granaries, hoarding in its burrow 4-8 times as much as it devours on
the surface. In recent years, the bandicoots have spread from the fields to become the
dominant rat in most of India's villages and cities.
1-6.
ENVIRONMENTAL DISTRIBUTION
a. General. Within their geographic range, the rats and mice are distributed
sporadically and are only abundant in certain environments. This distribution is due to
differences in the suitability of the various kinds of available environments and reflects
differences in the habits and needs of these three species.
b. House Mouse. The house mouse has the widest distribution of the three
commensal rodents and appears to be the least dependent on man over most of its
range. It nests close to its food supply and therefore usually more productive than the
roof rat or the Norway rat. It is found throughout the US. In some areas of the
Southwestern US, they are more abundant than any other species in cultivated and
recently abandoned fields. They have been captured in open tundra in Alaska miles
from any human settlement and have been found living 1,800 feet underground in a
coal mine.
c. Roof Rat. The roof rat is most common today through the Tropics. This is
true both in its native area and in areas where it has been introduced. In the US, it is
mainly confined to the warm southern states, along the Pacific Coast on into Western
Canada. They prefer rural areas and seacoast towns. It is only sporadically found in
the northern and central states. When the roof rat and the Norway rat compete for the
same area, the roof rat soon disappears from that area. The roof rat seems to be less
dependent on man than the Norway rat and it is common for them to live in wooded
areas away from man. The majority of the rural rats of the southeastern US are roof
rats.
d. Norway Rat. The Norway rat prefers the temperate areas, but if all the other
environmental needs are present in abundance, it will live in the tropic regions. It is big,
aggressive, tolerates cool weather, and prefers urban habitats. The Norway rat is
distributed throughout the US and southern Canada. There are areas within the
geographic range of the Norway rat where its numbers are very low. This is especially
true in the mountainous and arid regions of the West. Throughout most of its range in
North America, the Norway rat is closely associated with man and his buildings. In
certain situations, however, it can survive quite independently of man.
MD0173
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