Wikipedia

Leporidae

Rabbits and hares[1]
Temporal range: 53–0 Ma Eocene-Holocene
Arctic hare (Lepus arcticus)
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Lagomorpha
Family: Leporidae
Fischer de Waldheim, 1817
Type genus
Lepus
Linnaeus, 1758
Genera

Pentalagus
Bunolagus
Nesolagus
Romerolagus
Brachylagus
Sylvilagus
Oryctolagus
Poelagus
Caprolagus
Pronolagus
Lepus
†Aztlanolagus
†Nuralagus

Skeleton of Alaskan hare on display at the Museum of Osteology

Leporidae (/ləˈpɔːrɪdiː, -daɪ/) is the family of rabbits and hares (Lepus), containing over 70 species of extant mammals in all. Together with the pikas, the Leporidae constitute the mammalian order Lagomorpha. Leporidae differ from pikas in that they have short, furry tails and elongated ears and hind legs.

The common name rabbit usually applies to all genera in the family except Lepus, while members of the genus Lepus (comprising nearly half the species) are usually called hares. Like most common names, however, the distinction does not match current taxonomy completely; jackrabbits are members of Lepus, and members of the genera Pronolagus and Caprolagus are called red rock hares and hispid hares respectively.

Various countries across all continents except Antarctica and Australia have indigenous species of Leporidae. Furthermore, the European rabbit, Oryctolagus cuniculus, and the European hare, Lepus europaeus, have been introduced to Australia and to many other islands, where they pose serious ecological and commercial threats due to their adaptability and lack of natural predators.

Description

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Leporids are small to moderately sized mammals, adapted for rapid movement. They have long hind legs, with four toes on each foot, and shorter fore legs, with five toes each. The soles of their feet are hairy, to improve grip while running, and they have strong claws on all of their toes. Leporids also have distinctive, elongated and mobile ears, and they have an excellent sense of hearing. Their eyes are large, and their night vision is good, reflecting their primarily nocturnal or crepuscular mode of living.[2]

Leporids are all roughly the same shape and fall within a small range of sizes with short tails, ranging in overall length from the 21 cm (8 in) long Tres Marias cottontail to the 76 cm (30 in) long desert hare. Female leporids are almost always larger than males, which is unusual among terrestrial mammals.[3] It has been noted that the humerus bones of all leporids are extremely similar.[4]

The dental formula of leporids is 2.0.3.31.0.2.3 = 28, meaning that they have two pairs of upper and one pair of lower incisors, no canines, three upper and two lower premolars on each side, and three upper and lower molars on either side of the jaw.[5][6] Many leporids are classified by the characteristics of their teeth, and dental fossils, particularly the third upper premolar ("p3"), are often invaluable in identifying species.[7] The Amami rabbit is unique among the leporids in that its generic name, Pentalagus, is derived from the fact that it is often found without its third upper molar,[8] thus having 5 (penta-) total molars.[9]

Distribution, ecology, and behavior

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Diet

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Both rabbits and hares are almost exclusively herbivorous, although some hare species are known to eat carrion,[10][11] and some leporids will eat fungi as well.[12] Leporids feed primarily on grasses and herbs, although they also eat leaves, fruit, and seeds of various kinds. Easily digestible food is processed in the gastrointestinal tract and expelled as regular feces. In order to get nutrients out of hard to digest fiber, leporids ferment fiber in the cecum (in the GI tract) and then expel the contents as cecotropes, which are reingested (in a process known as cecotrophy). The cecotropes are then absorbed in the small intestine to utilize the nutrients,[13] and the undigestible portion is expelled as pellets that are not eaten. This process is comparable to the cud-chewing behavior of ruminants.[14]

Distribution

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Leporids are found worldwide and have adapted to a remarkable range of habitats, from desert to tundra, forests, mountains, and swampland. Some rabbits dig burrows for shelter, the exact form of which varies between species. Other rabbits do not dig burrows but use forms, usually under a bush. Hares rarely dig shelters of any kind, instead using forms, and their bodies are more suited to fast running than to burrowing.[2]

The adapatability of leporids has led to some species becoming invasive species upon introduction to exotic regions. Twelve species have been introduced outside of their native range, and three are considered to be invasive: the European rabbit, the European hare, and the eastern cottontail.[15] The introduction of the European rabbit and European hare to Australia and remote islands is a major factor in the leporids' global distribution.[16]

Ecology

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Rabbits are near the bottom of the food chain in many ecosystems, being prey for a wide array of predators. These include weasels, birds of prey, snakes, dogs, coyotes, feral cats, and many other carnivores. Some wild cats, such as the Iberian lynx, are specialists, relying heavily on native rabbit populations for their food.[17] Hares, too, have many predators, and rarely live past one year of age in the wild, though they have a potential lifespan of up to 12 years.[18] Leporids, wherever they are found, inevitably end up as part of human diets as well, being considered as bushmeat.[19]

Reproduction

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Leporids are typically polygynandrous, and some have highly developed social systems. Their social hierarchies determine which males mate. Rabbits are induced ovulators (ovulate during mating).[20] Species nesting below ground tend to have lower predation rates and have larger litters.[21]

The gestation period in leporids varies from around 28 to 50 days, and is generally longer in the hares. This is in part because young hares (called leverets) are born precocial (eyes and ears open, fully furred), while young rabbits (called kits) are born altricial (eyes and ears closed, no fur).[2] Higher latitudes correspond to shorter gestation periods.[22] Leporids can have several litters a year, which can cause their population to expand dramatically in a short time when resources are plentiful. Gestation period and litter size correspond to predation rates as well.[23]

Evolution

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The oldest known leporid species date from the late Eocene, by which time the family was already present in both North America and Asia. Over the course of their evolution, this group has become increasingly adapted to lives of fast running and leaping. For example, Palaeolagus, an extinct rabbit from the Oligocene of North America, had shorter hind legs than modern forms (indicating it ran rather than hopped) though it was in most other respects quite rabbit-like.[24] The last common ancestor of the leporids likely had features not present in the last common ancestor of the lagomorphs, according to a 2022 study of the extant and extinct known lagomorphs—an intercranial joint and a facial tilt, specifically.[25] Two as yet unnamed fossil finds—dated ~48 Ma (48 million yr) ago (from China) and ~53 Ma (53 million yr) ago (India)—while primitive, display the characteristic leporid ankle, thus pushing the divergence of Ochotonidae and Leporidae yet further into the past.[26]

The following cladogram is based on work done by Matthee and colleagues in 2004 and clarifications from Abrantes and colleagues in 2011, and is based on nuclear and mitochondrial gene analysis:[27]

Leporidae

Nesolagus (striped rabbits)

Poelagus (Bunyoro rabbit)

Pronolagus (red rock hares)

Romerolagus (volcano rabbit)

Sylvilagus (cottontails)

Brachylagus (pygmy rabbit)

Bunolagus (riverine rabbit)

Oryctolagus (European rabbit)

Caprolagus (hispid hare)

Pentalagus (Amami rabbit)

Lepus (hares)

Taxonomy

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Main article: List of leporids

Family Leporidae (rabbits and hares):[1]

See also

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Notes

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  1. ^ a b Hoffmann, R.S.; Smith, A.T. (2005). "Order Lagomorpha". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 194–211. ISBN 978-0-8018-8221-0. OCLC 62265494.
  2. ^ a b c Chapman, J.; Schneider, E. (1984). MacDonald, D. (ed.). The Encyclopedia of Mammals. New York: Facts on File. pp. 714–719. ISBN 978-0-87196-871-5.
  3. ^ Ralls, Katherine (June 1976). "Mammals in Which Females are Larger Than Males". The Quarterly Review of Biology. 51 (2): 245–276. doi:10.1086/409310. PMID 785524. S2CID 25927323.
  4. ^ Sen, S.; Pickford, M. (2022). "Red Rock Hares (Leporidae, Lagomorpha) past and present in southern Africa, and a new species of Pronolagus from the early Pleistocene of Angola" (PDF). Communications of the Geological Survey of Namibia. 24: 67–96.
  5. ^ Elbroch, Mark (2006). Animal Skulls : A Guide to North American Species. Mechanicsburg, PA: Stackpole Books. pp. 249–259. ISBN 978-0-8117-3309-0.
  6. ^ Pintus, Kathryn; Bourne, Debra. "Sylvilagus aquaticus - Swamp rabbit". Wildpro. Twycross Zoo. Archived from the original on 21 January 2018. Retrieved 31 March 2025.
  7. ^ Pelletier, Maxime (2021). "Morphological diversity, evolution and biogeography of early Pleistocene rabbits (Genus Oryctolagus)". Palaeontology. 64 (6): 817–838. doi:10.1111/pala.12575. ISSN 1475-4983.
  8. ^ Yamada, Fumio (2008), Alves, Paulo C.; Ferrand, Nuno; Hackländer, Klaus (eds.), "A Review of the Biology and Conservation of the Amami Rabbit (Pentalagus furnessi)", Lagomorph Biology, Berlin, Heidelberg: Springer Berlin Heidelberg, pp. 369–377, doi:10.1007/978-3-540-72446-9_25, ISBN 978-3-540-72445-2, retrieved 20 February 2025
  9. ^ Lyon Jr., Marcus Ward (1904). "Classification of the Hares and their Allies" (PDF). Smithsonian Miscellaneous Collections. 45: 428–431.
  10. ^ Best, Troy L.; Henry, Travis Hill (1994). "Lepus arcticus". Mammalian Species (457). American Society of Mammalogists (published 2 June 1994): 1–9. doi:10.2307/3504088. JSTOR 3504088. OCLC 46381503. S2CID 253989268.
  11. ^ "Snowshoe Hare". eNature: FieldGuides. eNature.com. 2007. Archived from the original on 16 January 2009. Retrieved 23 March 2008.
  12. ^ Maser, Chris; Maser, Zane; Molina, Randy (1988). "Small-mammal mycophagy in rangelands of central and southeastern Oregon". Journal of Range Management. 41 (4): 309–312. doi:10.2307/3899385. hdl:10150/645237. ISSN 0022-409X. JSTOR 3899385.
  13. ^ "Exploring a Rabbit's Unique Digestive System". Rabbits for Dummies. Retrieved 14 August 2013.
  14. ^ Pintus, Kathryn; Bourne, Debra. "Sylvilagus aquaticus - Swamp rabbit". Wildpro. Twycross Zoo. Archived from the original on 21 January 2018. Retrieved 31 March 2025.
  15. ^ Feldhamer, George A.; Merritt, Joseph F.; Krajewski, Carey; Rachlow, Janet L.; Stewart, Kelley M. (2020). Mammalogy: adaptation, diversity, ecology (5th ed.). Baltimore: Johns Hopkins University Press. pp. 359–360. ISBN 978-1-4214-3652-4. LCCN 2019017733.
  16. ^ Smith, Andrew T.; Johnston, Charlotte H.; Alves, Paulo C.; Hackländer, Klaus, eds. (2018). "The rabbits". Lagomorphs: Pikas, Rabbits, and Hares of the World. Johns Hopkins University Press. doi:10.1353/book.57193. ISBN 978-1-4214-2341-8. LCCN 2017004268.
  17. ^ Dickenson 2014, pp. 15–16
  18. ^ Carnell 2010, p. 36
  19. ^ Smith, Andrew T. (2018). "Introduction". In Smith, Andrew T.; Johnston, Charlotte H.; Alves, Paulo C.; Hackländer, Klaus (eds.). Lagomorphs: Pikas, Rabbits, and Hares of the World. Johns Hopkins University Press. doi:10.1353/book.57193. ISBN 978-1-4214-2341-8. LCCN 2017004268.
  20. ^ Bell, Diana; Smith, Andrew T. (2006) [copyright 2001]. "Lagomorphs". In Macdonald, David; Norris, Sasha (eds.). The Encyclopedia of Mammals. London: The Brown Reference Group. p. 695. ISBN 0-681-45659-0.
  21. ^ Virgós, Emilio; Cabezas-Díaz, Sara; Blanco-Aguiar, José Antonio (1 August 2006). "Evolution of life history traits in Leporidae: a test of nest predation and seasonality hypotheses". Biological Journal of the Linnean Society. 88 (4): 603–610. doi:10.1111/j.1095-8312.2006.00646.x. ISSN 1095-8312.
  22. ^ Chapman, Joseph A. (1 September 1984). "Latitude and Gestation Period in New World Rabbits (Leporidae: Sylvilagus and Romerolagus)". The American Naturalist. 124 (3): 442–445. Bibcode:1984ANat..124..442C. doi:10.1086/284286. JSTOR 2461471. S2CID 83584955.
  23. ^ Heldstab, Sandra A. (2021). "Habitat characteristics and life history explain reproductive seasonality in lagomorphs". Mammalian Biology. 101 (6): 739–757. doi:10.1007/s42991-021-00127-0. ISSN 1616-5047.
  24. ^ Savage, R.J.G.; Long, M.R. (1986). Mammal Evolution: an illustrated guide. New York: Facts on File. pp. 128–129. ISBN 978-0-8160-1194-0.
  25. ^ Wood-Bailey, A. P.; Cox, P. G.; Sharp, A. C. (2022). "The evolution of unique cranial traits in leporid lagomorphs". PeerJ. 10. e14414. doi:10.7717/peerj.14414. PMC 9744148. PMID 36518283.
  26. ^ Handwerk, Brian (21 March 2008). "Easter Surprise: World's Oldest Rabbit Bones Found". National Geographic News. National Geographic Society. Archived from the original on 22 March 2008.
  27. ^ de Sousa-Pereira et al. 2019

References

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