Rodents in Agriculture: A Broad Perspective

The largest taxonomic group of mammals is rodents, with over 2200 species known around the world [1]. More recently, it was stated that over 2500 species exist [2]. Many species exist on all continents, with the exception of Antarctica. Rodents have adapted to all ecosystems of the world, including tundra, alpine, temperate forests, grasslands, arid regions, and aquatic systems. They provide many ecosystem functions, including soil aeration and mixing, seed and spore dispersal, vegetation succession, and being an important food source for predatory animals. Some species of rodents are even consumed by people in some parts of the world. Most rodent species are small, secretive, nocturnal, adaptable, and have a keen sense of touch, taste, and smell. Most species have incisors that grow continuously throughout their lifespan, requiring constant gnawing to keep them sharp and at an appropriate length. Many species are active year-round, while some hibernate during the cold winter months, and some estivate during hot and dry summers. Rodent species vary in terms of their reproductive potential, but most are highly prolific, bearing a litter of several young every year with some even producing several litters per year. Some rodent species live relatively long lives (k-selected species), but most live short lives (r-selected species). Some species maintain stable populations, but some show peaks and valleys in population sizes [3]. This occurs with vole (Microtus) populations in the northern hemisphere, which peak every 3–5 years and crash thereafter. This is often related to weather and vegetation conditions, but also predatory pressures [4]. While most rodent species are relatively small and non-descript, they can vary widely in size from mice that weigh 10 g to capybara (Hydrochaerus) which can weigh 70 kg. A much broader background on rodents, including their evolution, morphology, diversity, social organization, behaviour, and ecology, has been reviewed [5]