Later, he undertook similar studies on British mouse and vole populations.
The vole population in a given area can vary greatly from year to year.
As a result of this exponential growth, vole populations can grow very large within a very short period of time.
Fencing for livestock has been installed downstream to help to provide connectivity with the nearest water vole population.
In years when the vole population is high, the numbers of their main predator, the owls, increase correspondingly and spread out.
There have also been positive effects on the rates of transfer and interbreeding in vole populations.
He has reported that the vole population at his study sites in summer and fall of 2004 was the lowest since 1992.
It will also wander nomadically in search of better food supplies during years when vole populations are low.
Cyclic fluctuations in vole populations have been variously interpreted as the result of intrinsic or extrinsic factors by different workers.
Despite the mutation rate, the vole population was booming.