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Nightjars - medium-sized nocturnal or crepuscular birds

Jamaican anole

The bright display of the Jamaican Tortoise Anole

Crepuscular animals are defined as animals that are most active at dawn and dusk (Davies, 2010).  While their eyes are often specialized for optimal vision in these low-light conditions, they also often have other senses that are increased such an acute sense of smell or hearing (Davies, 2010).

The word "Crepuscular" is derived from the Latin word crecpusculum, meaning "twilight." Crepuscular animals, in addition to being active at dawn and dusk, may also be active on very bright moonlit nights.   Within the definition of crepuscular are the terms matutinal (or "matinal") and vespertine, denoting species active only in the dawn or only in the dusk, respectively (Monkeyland, nd.)

Crepuscular actviity is thought to have evolved as an antipredator adaptation due to the fact that a large number of predators forage during the times that crepuscular animals are not active. Additionally, being active during these times of day assist the animals with the avoidance of intense heat.

The following is a nonexhaustive list of some crepuscular animals:  cats, dogs, rabbits, ferrets, guinea pigs, rats, prosimians, red pandas, deer, moose, chinchillas, the common mouse, skunks, wombats, quolls, spotted hyenas, bobcats, tenrecidae, capybaras, Common Nighthawk, Chimney Swift, American Woodcock, and Spotted Crake.

According to Davies, many adaptations are heightened due to the time of day these animals are active. Crepuscular animals frequently trade visual acuity for heightened light sensitivity. Owls are an excellent example of this adaptation. Many species also take advantage of a very acute sense of hearing, most notably bats. Color displays tend to be very bright, as seen in the crepuscular Jamaican Tortoise Anole Lizard who displays very brightly during dusk. 


Davies, Ella. (2010). The twilight zone: Where animals battle for dominion. Retrieved on

November 30, 2013 from http://news.bbc.co.uk/earth/hi/earth_news/newsid_9125000/9125617.stm. What are crepuscular animals?. (n.d.). Retrieved from http://www.monkeyland.co.za/index.php?comp=article&op=view&id=1922

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