crepuskulära

Crepuscular refers to organisms that are primarily active during the twilight periods of dawn and dusk. The term comes from Latin crepusculum, meaning twilight. In ecology, crepuscular activity describes a pattern that lies between diurnal (daytime) and nocturnal (nighttime) activity, and it can vary with season, weather, and life stage.

Crepuscular behavior is often an adaptation to balance several ecological pressures. Twilight hours offer milder temperatures and lower exposure to predators, while still providing sufficient light for foraging and navigation. For some species, these hours also coincide with the availability of specific resources, such as certain plants, insects, or prey that emerge at low light. Animals may exhibit two activity peaks around dawn and dusk, with resting periods during the brighter daytime or darker nighttime.

Examples of crepuscular organisms span many groups. Mammals such as white-tailed deer, rabbits, and raccoons are commonly described as crepuscular. Insects like moths and mosquitoes show crepuscular or dusk-active activity, while various bird species may be more active during twilight in certain habitats. Reptiles and some small mammals also display crepuscular patterns in response to temperature and predation risk.

Physiological and sensory adaptations support crepuscular life. Species often rely on vision suited to low light, such as a higher proportion of rod cells, and may possess enhanced hearing or tactile senses. Human activity and habitat modification can influence crepuscular patterns, causing shifts toward more diurnal or nocturnal activity in some populations. Crepuscular behavior is one of several overlapping temporal activity strategies used by organisms to optimize survival and reproduction.