Nocturnal animals are those who become active in the night hours. Owl, red fox, skunk and bats come under this category. The behavioral patterns exhibited by animals and birds are similar to man. The word ‘nocturnal’ refers to the preference of sleeping throughout the day and remaining awake and active at night.
According to the sleep pattern, animals have been broadly classified into three categories — Diurnal means those animals who remain active during the day, Crepuscular implies those animals who are very active at dawn and dusk, and finally the Nocturnal animals are those who are awake in the night hours and also stay active during that time. While most of the animals fall in the first category, some of them, like flying squirrel and mink, are quite active during dawn and dusk.
The nocturnal behavior exhibited by certain animals is due to the reason that it firstly adds a variety to the animal kingdom and secondly, they are meant for bringing ecological balance to the environment. Nocturnal behaviors are usually seen in the animals of the desert regions because nocturnal activities increase osmoregulation.
There are some of the nocturnal animals such as sea turtles and sea birds that prefer to make trips to the breeding grounds at night to lessen the chances of predation. These animals adapt to the nocturnal pattern in order to safeguard themselves and their offsprings. Otherwise, these are diurnal animals.
Most of the nocturnal animals’ senses are very strong. Their senses of smelling, hearing and also sight are especially heightened to meet the night illumination requirements. There are some exceptional nocturnal animals whose sense of sight is easily adapted to day as well night illumination, whereas there are some like bush-babies and bats whose night vision is only strong at nights making them active only during the night hours. They usually burrow deep and sleep in these burrows during the whole day and then wake up at night to hunt.