Diurnal, Nocturnal and Crepuscular


Diurnal animals are most active during the day, and sleep at night.

Most animals first evolved to be diurnal (including nocturnal creatures). Advanced colour and vivid vision is an adaptation of diurnal animals. Animals that mainly rely on vision to hunt for food are usually diurnal. Diurnal prey have the advantage of easily spotting predators from a distance.

Most birds are diurnal, however, many species migrate at night to avoid predation.

Animals known to be diurnal include most reptiles (Australian snakes are both diurnal and nocturnal), emus, pollinator insect species, and primates (including humans).


Nocturnal animals and birds are active during the night and sleep during the day. Nocturnal creatures evolved adaptations for being active at night in order to avoid predators and reduce competition with other species.

Nocturnal creatures generally have highly developed senses of hearing, smell, and specially adapted eyesight. Many nocturnal creatures have large eyes in comparison with their body size to compensate for the lower light levels at night.

Nocturnal birds include owls, frogmouths, night parrot, and nightjars. Nocturnal animals include the bandicoot, bilby, cane toad, crocodile, dingo, fly fox, kangaroo (most, a few are crepuscular), koala (mostly), platypus, possum, quokka, quoll, Tasmanian devil, wallaby, wombat, woylie. Australian snakes are both nocturnal and diurnal.


Crepuscular animals are those that are active primarily during twilight. This is distinguished from Diurnal (daylight) and Nocturnal (hours of darkness). The term is not precise, however, as some crepuscular animals may also be active on a moonlit night or during an overcast day. The term Matutinal is used for animals that are active only before sunrise, and Vespertine for those active only after sunset.

The time of day an animal is active depends on a number of factors. Predators need to link their activities to times of day at which their prey is available, and prey try to avoid the times when their principal predators are at large. The temperature at midday may be too high or at night too low. Some creatures may adjust their activities depending on local competition. Therefore, for many varied reasons, crepuscular activity may best meet an animal’s requirements by compromise.

Many familiar mammal species are crepuscular, including some bats, hamsters, cats, dogs, rabbits, ferrets, and rats. Australian crepuscular mammals include wombats, kangaroos (some), wallabies, quolls, possums and marsupial gliders.

Many moths, beetles, and other insects are crepuscular and vespertine.

Crepuscular is derived from the Latin term for twilight.


Vespertine indicates something of, relating to, or occurring in the evening.

In botany, a vespertine flower is one that opens or blooms in the evening.

In zoology, the term is used for a creature that becomes active at dusk, such as bats and owls. Strictly speaking, however, the term means that activity ceases during the hours of full darkness and does not resume until the next evening. Activity that continues throughout the night is nocturnal.

Vespertine behaviour is a special case of crepuscular behaviour. Like crepuscular activity, vespertine activity is limited to dusk rather than full darkness. Unlike vespertine activity, crepuscular activity may resume in dim twilight before dawn. Matutinal refers to activity limited to the dawn twilight.

The word vespertine is derived from the Latin word vesper which means evening.


In ecology, matutinal crepuscular animals are those that are significantly active during pre-dawn or early morning hours. During the morning’s twilight period and shortly thereafter, these animals partake in important tasks, such as scanning for mates, mating, and foraging. Matutinal behaviour is thought to be adaptive because there may be less competition between species, and sometimes even a higher prevalence of food during these hours. It may also serve as an anti-predatory adaptation by allowing animals to sit between the brink of danger that may come with Nocturnal and Diurnal activity.

The word is derived from late Latin matutinalis which in turn comes from early from Latin matutinus and means of or occurring in the morning.

NOTE: Vespertine and Matutinal species are commonly considered as special cases of being Crepuscular.


Cathemeral animals have sporadic and irregular active spurts during parts of both day and night.

Lions and some species of lemur are known for being cathermal.