Crepuscular animal

"Crepuscular" redirects here. For the atmospheric optical effect, see Crepuscular rays. For a definition of the term "crepuscular", see the Wiktionary entry crepuscular.
Photo of a red fox standing outdoors among forest understory
A red fox at dusk
Photo of a cat sitting on a balcony ledge. Its coat is grey with black stripes and some white in its undercoat.
A domestic cat under low light

In zoology, a crepuscular animal is one that is active primarily during the twilight period: being matutinal (active around dawn), vespertine/vespertinal (active around dusk), or both. This is distinguished from diurnal and nocturnal behavior, in which an animal is active during the daytime or at night, respectively. Some crepuscular animals may also be active by moonlight or during an overcast day, under lower-light conditions.

A number of factors affect the time of day an animal is active. Predators hunt when their prey is available, and prey try to avoid the times when their principal predators are at-large. The temperature may be too high at midday or too low at night. Some creatures may adjust their activities depending on local competition.

Etymology and usage

The word crepuscular derives from Latin crepusculum, 'twilight'. Its sense accordingly differs from diurnal and nocturnal behavior, which respectively peak during hours of daytime and night. The distinction is not absolute, because crepuscular animals may also be active on a bright moonlit night or on a dull day. Some animals casually described as nocturnal are in fact crepuscular.

Special classes of crepuscular behaviour include matutinal, or "matinal", animals active only in the dawn, and vespertine, only in the dusk. Those active during both times are said to have a bimodal activity pattern.

Adaptive relevance

Photo of a forest path with fireflies in flight
Fireflies at twilight, long exposure

The various patterns of activity are thought to be mainly anti­predator adaptations, though some could equally well be predatory adaptations. Many predators forage most intensively at night, whereas others are active at midday and see best in full sun. The crepuscular habit may both reduce predation pressure, increasing the crepuscular populations, and offer better foraging opportunities to predators that increasingly focus their attention on crepuscular prey until a new balance is struck. Such shifting states of balance are often found in ecology.

Some predatory species adjust their habits in response to competition from other predators. For example, the sub­species of short-eared owl that lives on the Galápagos Islands is normally active during the day, but on islands like Santa Cruz that are home to the Galapagos hawk, the owl is crepuscular.

Apart from the relevance to predation, crepuscular activity in hot climates may be the most effective way of avoiding heat stress while capitalizing on available light.

Crepuscular flight activity is preferred by some animals, such as the walnut twig beetle, due to warmer temperatures, moderate wind speeds, and low barometric pressure.

Crepuscular activity can be influenced by the lunar cycle due to the change in nocturnal light levels. This creates changes in animal sleep, reproduction, and foraging behaviours; crepuscular animals often become less active during periods of low light.

Migration

Animal patterns of activity sometimes change during migration due to changes in environmental conditions. Mule deer are crepuscular, but they are only active at dusk before and during migration. In the spring, they are only active at dawn because the snow is at its hardest, so it is easier for the deer to move without sinking in the snow.

During migration, some types of swallow are active primarily during daytime hours with some activity during twilight hours.

Human impact on crepuscular behaviour

Crepuscular animal activity is affected by human activity, because humans are diurnal (active during day). Crepuscular animals are less likely to participate in typical foraging or reproductive behaviors and experience increased stress and mortality when humans are present.

Animals may change their usual activity patterns in response to the presence of humans. For example, Asian black bears may avoid areas with high human activity during the day, but go to these locations during twilight or night­time hours.

Light pollution impacts crepuscular behaviour because it mimics natural light conditions, leading crepuscular animals to behave as they would on nights with more moonlight.

Occurrence of crepuscular behaviour

Photo of an ocelot at night crouching on a tree branch
Ocelots are active at night, especially during dawn and dusk.

Many familiar mammal species are crepuscular, including the endangered Amazon river dolphin, some species of bats, hamsters, housecats, stray dogs, rabbits, ferrets, rats, jaguars, ocelots, bobcats, servals, strepsirrhines, red pandas, bears, deer, moose, sitatunga, capybaras, chinchillas, the common mouse, skunks, squirrels, foxes, wombats, wallabies, possums and marsupial gliders, tenrecs, and spotted hyenas.

Snakes, lizards, and frogs, especially those in desert environments, may be crepuscular.

Crepuscular birds include the common nighthawk, barn owl, owlet-nightjar, chimney swift, American woodcock, spotted crake, white-breasted waterhen, and European nightjar.

Many moths, beetles, flies, and other insects are crepuscular and vespertine.[citation needed] For example, Coprophanaeus ensifer, a South American necrophagous beetle, is most active at dusk and dawn.

See also

References

  1. ↑ "Glossary". National Museum of Natural History. North American Mammals. Smithsonian. Archived from the original on 25 May 2017. Retrieved 16 July 2017.
  2. 1 2 3 4 5 6 7 "Crepuscular". Macmillan Science Library: Animal Sciences. Macmillan Reference. 2001–2006. Retrieved 11 July 2011.
  3. ↑ Winn, Philip (2001). Dictionary of Biological Psychology. Taylor & Francis. ISBN 0-415-13606-7.
  4. ↑ Caro, Tim (2005). Antipredator Defenses in Birds and Mammals. University of Chicago Press. ISBN 978-0-226-09436-6.
  5. ↑ Frederick, Prince (15 April 2006). "Night herons in the day!". The Hindu. Retrieved 15 January 2012.{{cite news}}: CS1 maint: deprecated archival service (link)
  6. ↑ Merck, John. "The community of terrestrial animals". Field Studies II: The Natural History of the Galápagos Islands. University of Maryland Department of Geology. Archived from the original on 23 June 2012. Retrieved 15 January 2012.
  7. ↑ Chen, Yigen; Seybold, Steven J. (26 August 2014). "Crepuscular Flight Activity of an Invasive Insect Governed by Interacting Abiotic Factors". PLOS ONE. 9 (8) e105945. Bibcode:2014PLoSO...9j5945C. doi:10.1371/journal.pone.0105945. ISSN 1932-6203. PMC 4144967. PMID 25157977.
  8. 1 2 3 Evens, Ruben; Kowalczyk, Céline; Norevik, Gabriel; et al. (9 June 2020). "Lunar synchronization of daily activity patterns in a crepuscular avian insectivore". Ecology and Evolution. 10 (14): 7106–7116. Bibcode:2020EcoEv..10.7106E. doi:10.1002/ece3.6412. ISSN 2045-7758. PMC 7391349. PMID 32760515.
  9. ↑ Jakopak, Rhiannon P.; Sawyer, Hall; LaSharr, Tayler N.; et al. (1 October 2022). "Diel timing of migration is not plastic in a migratory ungulate". Animal Behaviour. 192: 51–62. doi:10.1016/j.anbehav.2022.07.008. ISSN 0003-3472. S2CID 251695259.
  10. ↑ Imlay, Tara L.; Taylor, Philip D. (22 July 2020). "Diurnal and crepuscular activity during fall migration for four species of aerial foragers". The Wilson Journal of Ornithology. 132 (1): 159. doi:10.1676/1559-4491-132.1.159. ISSN 1559-4491. S2CID 220714544.
  11. ↑ Nix, Joshua H.; Howell, Ryan G.; Hall, Lucas K.; et al. (1 January 2018). "The influence of periodic increases of human activity on crepuscular and nocturnal mammals: Testing the weekend effect". Behavioural Processes. 146: 16–21. doi:10.1016/j.beproc.2017.11.002. ISSN 0376-6357. PMID 29122640. S2CID 22906920.
  12. ↑ Ikeda, Takashi; Higashide, Daishi; Shichijo, Tomoya (1 December 2022). "Impact of human disturbance in Japan on the distribution and diel activity pattern of terrestrial mammals". Journal for Nature Conservation. 70 126293. Bibcode:2022JNatC..7026293I. doi:10.1016/j.jnc.2022.126293. ISSN 1617-1381. S2CID 252985684.
  13. ↑ Beck, Alan M. (2002). The Ecology of Stray Dogs: A Study of Free-Ranging Urban Animals. Purdue University Press. ISBN 978-1-55753-245-9. Retrieved 13 April 2012 – via Google Books.
  14. 1 2 Williams, David L. (2012). Ophthalmology of Exotic Pets. John Wiley & Sons. pp. 73, 88. ISBN 978-1-4443-6125-4. Retrieved 23 June 2017.
  15. ↑ Schaul, Jordan Carlton (6 April 2011). "The Kodiak Cubs Meet Their Neighbors, The American Black Bears". National Geographic Voices. National Geographic Society. Retrieved 15 July 2017.[dead link]
  16. ↑ "White-Tailed Deer". Animals. National Geographic Partners, LLC. 12 March 2010. Archived from the original on 23 October 2016. Retrieved 15 July 2017.
  17. ↑ Robertson, Jeanne M.; Bell, Rayna C.; Loew, Ellis R. (1 June 2022). "Vision in dim light and the evolution of color pattern in a crepuscular/nocturnal frog". Evolutionary Ecology. 36 (3): 355–371. Bibcode:2022EvEco..36..355R. doi:10.1007/s10682-022-10173-w. ISSN 1573-8477. S2CID 247812966.
  18. ↑ Audubon, John J. (1827–1838). "Plate 171: Barn Owl". The Birds of America.
  19. ↑ Boyes, Steve (7 October 2012). "Top 25 Wild Bird Photographs of the Week #23". National Geographic Voices. National Geographic Society. Archived from the original on 7 May 2017. Retrieved 15 July 2017.
  20. ↑ Endres, Ana Aline; Hernández, Malva Isabel Medina; Creão-Duarte, Antônio José (September 2005). "Considerações sobre Coprophanaeus ensifer (Germar) (Coleoptera, Scarabaeidae) em um remanescente de Mata Atlântica no Estado da Paraíba, Brasil" [Notes about Coprophanaeus ensifer (Germar) (Coleoptera, Scarabaeidae) in a remnant of the Atlantic Forest in the State of Paraíba, Brazil]. Revista Brasileira de Entomologia [Brazilian Journal of Entomology] (in Brazilian Portuguese and English). 49 (3). São Paulo: Brazilian Society of Entomology: 427–429. doi:10.1590/S0085-56262005000300014. eISSN 1806-9665.