Voles are small, mouselike rodents often confused with mice, moles, or shrews. They have stocky bodies, short tails, small eyes, and ears obscured by fur. Their fur is typically brown, gray, or tan. These rodents inhabit various environments across the Northern Hemisphere, including grassy fields, gardens, orchards, and woodlands, favoring dense ground cover. Voles construct intricate tunnel systems and visible surface runways.
Understanding Vole Activity Cycles
Voles remain active year-round and do not hibernate. Their activity is commonly crepuscular, peaking during dawn and dusk. However, voles show considerable flexibility, active during the day (diurnal) or night (nocturnal) depending on various circumstances. They might be observed moving or foraging at any time.
Activity often occurs in short, synchronized bursts across a population. Foraging might happen throughout the day, with some studies noting increased activity during specific nighttime hours for certain food types, alongside brief bursts in the mid-morning. Amargosa voles show the highest activity during crepuscular periods, followed by nocturnal and then diurnal times, with pronounced seasonal variations influencing these patterns. Diurnal activity tends to be higher in winter, while nocturnal activity increases during the summer months.
Key Influences on Vole Behavior
Voles adjust their activity to avoid predators, often becoming more active when predation risk is lower, such as during crepuscular hours or new-moon phases. Conversely, an increase in predator presence can drive voles to become more nocturnal. They stay near dense vegetation or other cover, providing quick concealment from aerial predators like hawks and owls.
Food availability is another factor shaping vole behavior. As primarily herbivores, they consume grasses, seeds, roots, and bark. When food is abundant, they forage more frequently, but in winter, when green vegetation is scarce, their diet shifts to bark, roots, and stored bulbs. The nutritional quality of available food also influences their dietary choices.
Weather conditions also influence their activity, with voles altering their schedules to avoid extreme temperatures. For example, some species may adopt a crepuscular pattern to mitigate intense heat or cold. Wet and cold weather can directly influence their typical activity rhythms. In winter, voles continue to be active beneath snow cover, constructing tunnels that provide insulation and access to food sources.
Population density also affects how and when voles are active. An increase in the number of individuals within a given area can lead to more diurnal activity, potentially due to heightened social tensions in crowded habitats. Such high densities can also impact reproductive rates, sometimes decreasing reproductive output.