The European badger (Meles meles), a common, primarily nocturnal mammal across its continental range. Badgers spend daylight hours resting within complex underground tunnel systems known as setts. Their activity is heavily regulated by the cycle of light and dark, which dictates when they emerge to forage and socialize.
The Daily Activity Cycle
Badgers’ activity peaks around dusk and continues throughout the night. They typically emerge from their setts shortly after sunset, often pausing to sniff the air for any immediate danger before beginning their nightly routine. In one study, badgers were found to be active for an average of just over eight hours per night, traveling several kilometers in that time.
The trigger for emergence is ambient light levels rather than a specific clock time. This preference for darkness is an adaptive behavior that helps them avoid human activity and potential predation. They continue their activity until just before sunrise, at which point they retreat back into the sett to rest for the day.
Seasonal Changes in Activity Duration
The total amount of time badgers spend active above ground changes significantly with the seasons, largely driven by temperature and food availability. During the long summer and early autumn nights, badgers maximize their foraging time to build up reserves. This period of intense eating, known as hyperphagia, is necessary to accumulate the fat reserves they rely on when food is scarce.
In winter, particularly in northern regions with harsh conditions, their activity levels drop sharply, with above-ground movement reduced by up to 93% between November and February. Badgers do not truly hibernate, but they enter a state of torpor, or winter sleep, where they remain in the sett for days or weeks. Their body temperature decreases by several degrees to conserve energy, allowing them to metabolize the fat reserves built up in the autumn.
The duration of this winter inactivity is directly related to the severity of the cold, which affects the availability of their main food source, earthworms. In milder climates, badgers may remain active year-round, while those in harsher climates can stay inactive for up to six months, doubling their body weight in the active season to compensate. Badgers may still emerge briefly during warmer winter spells to forage, but their focus remains on energy conservation.
The Purposes of Nocturnal Activity
The primary purpose of the badger’s nightly emergence is extensive foraging to meet their substantial energy requirements. Earthworms form the core of their diet, often making up around 60% of their intake, and an adult can consume over 200 worms in a single night. They use their keen sense of smell, rather than their relatively poor eyesight, to locate these and other food sources like grubs, snails, and small mammals.
Beyond feeding, the nocturnal period is important for social maintenance and territorial communication within their clan. Badgers use scent glands, particularly those near the tail, to mark their territory and to “musk” or scent-mark each other, which helps tighten social bonds. They also engage in social activities near the sett, such as mutual grooming and play. Furthermore, they maintain their territory by using latrines—shallow pits for defecation—strategically placed on territorial boundaries to communicate with neighboring badger groups.