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Living OrganismsAnimalia / Craniata / Mammalia / Lagomorpha / Leporidae / Sylvilagus / Species

Sylvilagus audubonii - Desert cottontail (Click photographs/illustrations for full picture & further details)

 

INDEX - INFORMATION AVAILABLE

GENERAL & REFERENCES

APPEARANCE / MORPHOLOGY

LIFE STAGES / NATURAL DIET / PHYSIOLOGY

BEHAVIOUR

HABITAT & RANGE

CONSERVATION

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General and References

Alternative Names (Synonyms)

  • Audubon's cottontail. (B285.w5c, B430.w2, W2.Apr08.w75)
  • Sylvilagus vallicola. (B607.w20)
  • Sylvilagus audubonii arizonae. (B607.w20)
  • Sylvilagus audubonii baileyi. (B605.5.w5, B607.w20)
  • Sylvilagus audubonii cedrophilus. (B607.w20)
  • Sylvilagus audubonii confinis. (B605.5.w5, B607.w20)
  • Sylvilagus audubonii goldmani. (B605.5.w5, B607.w20)
  • Sylvilagus audubonii laticinctus. (B607.w20)
  • Sylvilagus audubonii major. (B607.w20)
  • Sylvilagus audubonii minor. (B605.5.w5, B607.w20)
  • Sylvilagus audubonii neomexicanus. (B605.5.w5, B607.w20)
  • Sylvilagus audubonii parvulus. (B605.5.w5, B607.w20)
  • Sylvilagus audubonii rufipes. (B607.w20)
  • Sylvilagus audubonii sanctidiegi. (B607.w20)
  • Sylvilagus audubonii warreni. (B607.w20)
  • Lepus audubonii. (J469.106.w1)
  • Lepus baileyi (J469.106.w1)
  • Lepus laticinctus (J469.106.w1)

Names for new-borns / juveniles

Names for males

Names for females

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General Appearance

Adult:

Specific Sylvilagus audubonii Information

  • A grey rabbit with a white underside. (B605.5.w5); this is a relatively large and long-legged species. (B430.w2, J469.106.w1)
  • "All cottontails have relatively large ears and feet." (B605.5.w5)

Newborn:

Specific Sylvilagus audubonii Information

Similar Species

--

Sexual Dimorphism

--

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References

Species Authors & Referees

Author: Kathryn Pintus BSc MSc MSc (V.w115); ; Dr Debra Bourne MA VetMB PhD MRCVS (V.w5)

ORGANISATIONS

ELECTRONIC LIBRARY
(Further Reading)
Click image for full contents list of ELECTRONIC LIBRARY

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Husbandry Information

Notes

  • --

Management Techniques

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Appearance / Morphology

Measurement & Weight

Notes

LENGTH
Adult:

Specific Sylvilagus audubonii Information

  • Range: 372-397 mm; average: 385 mm. (B430.w2)
  • Males 372 - 397 mm (mean 385.4 mm). (J469.106.w1)
  • Females: 375 - 400 mm (mean 385.4 mm). (J469.106.w1)
  • Females are about 2% percent larger than males. (B430.w2, J469.106.w1)

Newborns:

Specific Sylvilagus audubonii Information

  • Total length:
    • 90 mm (Sample size = 1; very young). (B287)
    • 90 mm (J469.106.w1)
    • Average: 117 mm (Sample size = 9; stillborn). (B287)

HEIGHT
Adults and sub-adults: --
Juveniles: --

WEIGHT
Adult:

Specific Sylvilagus audubonii Information

  • 755-1,250 g. (B430.w2)
  • 1,000 g. (B605.5.w5)
  • Males 755.7 - 907.5 g, mean 841.0 g. (J469.106.w1)
  • Females 883 - 1,250 g, mean 988.5 g. (J469.106.w1)

Newborns:

Specific Sylvilagus audubonii Information

  • Average: 32.8 g (Sample size = 9; stillborn). (B287)
  • Average: 36 g; Range: 33-40 g. (Sample size = 3). (B287)

GROWTH RATE --

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Head and Neck

Notes

GENERAL HEAD STRUCTURE:
Adult:

Specific Sylvilagus audubonii Information

  • Long, pointed ears with sparse fur on the inner surface. (J469.106.w1)
  • Ear length (from notch): males70 - 71 mm (mean 70.5 mm); females 72 - 75 mm (mean 72.8 mm). (J469.106.w1)

Newborn: 

Specific Sylvilagus audubonii Information

  • Ear length 155 mm. (J469.106.w1)

DENTITION:
Adult:

General Information

  • Rabbits and hares have a total of 28 teeth. (B285.w5a)
  • The lower tooth rows are closer together than the upper tooth rows. (B147)
  • Lagomorphs differ from rodents by having two pairs of upper incisors rather than just the one pair. The additional set of incisors are called peg teeth and are found directly behind the long pair in the upper jaw. (B147, B285.w5a, B605.1.w1)
  • At birth, lagomorphs actually have three pairs of upper incisors, but they quickly lose the outer incisor on each side. (B147)
  • The incisors are covered completely by enamel. (B147)
  • The upper incisors' roots are found in the skull's premaxillary bones. However, the length of the lower incisors' roots varies. (B147)
    • [Note: lagomorphs have teeth which grow throughout their lives. For this reason the portion of the teeth which is not exposed (not above the gum line) is strictly speaking not a "root"; however, it is sometimes convenient to describe it as a root.]
  • The first upper incisors have a straight cutting edge. (B147)
  • The peg teeth lack a cutting edge. (B147)

EYES:
Adult:

General Information

  • Lagomorph eyes are positioned such that they allow for good broad-field vision. (B285.w5a)
  • Hares and rabbits have large eyes which are adapted to both their crepuscular and nocturnal activity patterns. (B285.w5b)
  • Leporids have "large eyes to increase visual acuity in dim light." (B430.w2)

Newborn: --

EARS:

Specific Sylvilagus audubonii Information

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Legs, Spine and Tracks

Notes

Specific Sylvilagus audubonii Information
  • Long legs. (B430.w2)
  • Slender feet. (B430.w2, J469.106.w1)
  • Feet lack the long fur that other Sylvilagus species have. (B430.w2, B605.5.w5, J469.106.w1)
  • Hind foot length: males 83 - 94 mm (mean 88 mm); females 81 - 93 mm (mean 90.1 mm). (J469.106.w1)
  • Neonate: length 10 mm. (J469.106.w1)

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Tail

Notes

Specific Sylvilagus audubonii Information
  • Length: between 45 and 60 mm (average 56 mm). (B430.w2)
  • Large tail. (B430.w2, B605.5.w5, J469.106.w1))
  • The upperpart of the tail is dark, and the underside is white. (B430.w2, J469.106.w1)
  • Length male 45 - 60 mm (mean 56 mm); females 39 - 56 mm (mean 51.3 mm). (J469.106.w1)
  • Neonate: tail 10 mm. (J469.106.w1)

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Skin / Coat / Pelage

Notes

Adult:

Specific Sylvilagus audubonii Information

  • The upperparts are grey, as is the tail. The underside is white. (B605.5.w5)
  • The inner surface of the ears is sparsely haired. (B430.w2, B605.5.w5, J469.106.w1)
  • The vibrissae (whiskers) are usually black. (B430.w2, J469.106.w1)
  • The pelage on the feet is shorter and less dense than in many Sylvilagus spp.. (B430.w2, J469.106.w1)

Sylvilagus spp. General Information:

Adult Colour variations: --

Newborn / Juvenile: --

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Detailed Anatomy Notes
(Summary information provided for pertinent species-specific data cross-referenced in Wildpro)

Notes

Skull

Sylvilagus spp. General Information:

  • Species of this genus have an interparietal bone. (B605.5.w5)
  • The skull has a highly fenestrated maxillary bone. (B605.5.w5)
Female reproductive tract

Specific Sylvilagus audubonii Information

  • Four pairs of mammary glands - one pectoral, two abdominal, one inguinal. (J469.106.w1)
Male reproductive tract

Lagomorph general information

  • Male lagomorphs lack a baculum. (B147)
  • Testes of lagomorphs are in the scrotum located in front of the penis. (B147)

Sylvilagus spp. General Information:

  • Males have inguinal and coagulating glands. (B287)

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Life Stages / Natural Diet / Physiology

Life Stages

Notes

BREEDING SEASON:

Specific Sylvilagus audubonii Information 

  • Known to breed year-round. (B430.w2)
  • However, sexual activity is usually limited to eight months. (B430.w2)
  • "The length of the breeding season varies from year-round to seven months depending on location." (B605.5.w5)
  • The breeding season usually lasts for between seven to nine months, beginning in December or January. (B605.5.w5)
  • In central California (USA), mating occurs in the autumn and spring. (B287)
  • In California, certainly December through June; year round breeding has been reported. (J469.106.w1)
  • In Arizona, January to August or September. (J469.106.w1)
  • In Texas, starting only late February or early March. (J469.106.w1)

OESTRUS / OVULATION:

General Information

GESTATION / PREGNANCY:

General Information

  • Under adverse conditions (such as during climatic or social stress), female lagomorphs are able to resorb embryos. (B285.w5a)
  • It is thought that some lagomorph species are able to conceive a second litter even before the last young is born; this is known as superfetation. (B285.w5a)

Specific Sylvilagus audubonii Information

  • Gestation period is approximately 28 days. (B147)
  • Gestation period 28 days. (J469.106.w1)
  • Gestation lasts between 28 and 30 days. (B430.w2)
  • Gestation is usually between 26 and 30 days. (B287)
  • The time of year at which pregnant females are found varies depending on the region:
    • Arizona, USA: January-August.
    • California, USA: February-June, December.
    • Mexico: April, July and December (this information is derived from few data).
    • South Dakota, USA: May-July.
    • Sinaloa, Mexico: One pregnant found in June.
    • Southeastern Montana, USA: One pregnant female found in July.
    • New Mexico, USA: July.
    • Nebraska, USA: July.

    (B287)

PARTURITION / BIRTH:

General Information

  • Newborn rabbits are born with very little or no fur, and their eyes do not open until 4-10 days after birth. (B285.w5b)
  • Rabbits produce altricial kittens (B285.w5b, B430.w2) which are born into fur-lined nests built either under dense cover or within underground chambers. (B285.w5b)

Specific Sylvilagus audubonii Information

  • In southwestern USA, young are born year round. (B287)

NEONATAL / DEVELOPMENT:

General Information

  • Young are only suckled briefly once every 24 hours. (B285.w5b)
  • Rabbit kittens remain together within their breeding chambers. (B285.w5)

Sylvilagus spp. General Information:

  • Born furred but blind. Eyes open between 2 and 10 days of age. (B287)
  • Young are altricial, and are born naked. (B605.5.w5)

Specific Sylvilagus audubonii Information

  • Altricial young. (B430.w2)
  • Sparsely haired. (J469.106.w1)
  • When the hair in the nest was touched, young were reported to lung upwards with a "gupp" sound. (J469.106.w1)
  • Eyes open by ten days. (J469.106.w1)
  • Young leave nest at or before two weeks of age. (B287)
  • Leave the nest at 10 - 14 days but stay near the nest for as long as three weeks. (J469.106.w1)
  • The young are able to forage for themselves at approximately two to three weeks of age. (B430.w2)
  • Weaned between three and four weeks of age. (B287)

LITTER SIZE:

General Information

  • The size of litters produced by leporids at northern latitudes tends to be greater than those produced by leporids at southern latitudes. (B430.w2)

Specific Sylvilagus audubonii Information

  • Two to four young per litter. (B430.w2)
  • Average 2.6 to 3.6 young per litter. (B605.5.w5)
  • Compared to other species within this genus, the Desert cottontail produces small-sized litters. (B605.5.w5)
  • Mean litter sizes reported as 3.6 (California), 2.6 (first litters in Texas), 2.7 and 2.9 in Arizona. (J469.106.w1)

TIME BETWEEN LITTERS / LITTERS PER YEAR:

General Information

  • The inter-birth interval in lagomorphs is reduced by the phenomenon of induced ovulation, and post-partum oestrus, which allows females to conceive immediately after she has given birth. (B285.w5a)
  • A female can produce up to three or four litters per year. (B430.w2)

Specific Sylvilagus audubonii Information

  • This species produces between one and seven young per year, though three or four appears to be most common. (B287)
  • Estimated five litters per year. (J469.106.w1)

LACTATION / MILK PRODUCTION: 

General Information

  • Leporids only release milk once in every 24 hour period. (B285.w5b)
  • Leporid milk has a very high fat and protein content, and as such is highly nutritious. Although the lactation period is brief, the milk is pumped into the young at a high speed.(B285.w5b)
  • The lactation period has a duration of between 17 and 23 days. (B285.w5b)

Specific Sylvilagus audubonii Information

  • The females nurses the young within a form or nest. (B430.w2)
  • Weaned between three and four weeks of age. (B287)
  • Mexico: Lactation has been reported in April, June and July. This is based on few data. (B287)
  • New Mexico, USA: One female was known to be lactating in May. (B287)#

SEXUAL MATURITY:

  • Young of this species are thought to reach sexual maturity from as early as 80 days of age. (B147, J469.106.w1
  • Sexual maturity occurs early in this species, with some animals being known to have mated at three months of age. (B430.w2)
  • Females first mate in the summer of their birth. (B287)
  • Females first conceive at approximately 80 days of age. (B287)

MALE SEASONAL VARIATION:

Specific Sylvilagus audubonii Information

  • Sperm production in this species occurs year-round in Arizona, USA, though levels are low between September and November. (B287)
  • Epididymal sperm: 107 days. (B287)
  • Testes: low between September and October in Arizona, USA. (B287)

LONGEVITY / MORTALITY:

General Information 

  • Rabbits and hares in the wild live for less than a year on average; a maximum age of 12 years has been recorded in a couple of species. (B285.w5b)

Specific Sylvilagus audubonii Information

  • Generally short-lived: in one study, only 7/29 passed one year old and the oldest rabbit found was only 19 months of age. (J469.106.w1)

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Natural Diet

Notes

NATURAL DIET:

General Information

  • Lagomorphs only eat vegetation, mainly grasses and other herbaceous plants. Bark from young trees and small shrub stems may be eaten when food supplies are scarce. (B147, B285.w5c, B430.w2)

Sylvilagus spp. General Information:

  • Cottontails eat a wide variety of plants, the majority of which are herbaceous species. (B147, B285.w5c)
  • During the winter months in colder regions, cottontails feed on the bark and twigs of woody vegetation. (B147, B285.w5c)

Specific Sylvilagus audubonii Information

  • Eats a variety of grasses, shrubs and forbs. (B430.w2)

  • Seasonal availability of food plants appears to be the most important factor influencing the diet. (B430.w2, J469.106.w1)

  • The following plants are known to be an important part of its diet:

    • Johnson grass (Sorghum halepense). (B430.w2)

    • Sow thistle (Sonchus). (B430.w2)

    • Honeysuckle (Lonicera). (B430.w2)

    • Sedges (Carex). (B430.w2)

    • Blackberries (Rubus). (B430.w2)

  • Grasses, sedge (Carex sp.), rush (Juncus sp.), willow, Quercus lobata - Valley oak, Monti perfoliata - Miner's lettuce, Rubus vitifolius - Blackberry, Rosa californicus - Californian wild rose, Marrubium vulgare - Hoarhound, Baccharis douglasii and Artemesia vulgaris - California mugwort. have been recorded. (J469.106.w1)

  • In Sacramento Valley, California, various grasses plus Convolvulus sp. (morning glory), Malva borealis - Bull mallow, Lonicera sp. (honeysuckle), Sonchus asper - Sow thistle, plus carrots (pulled), cultivated hollyhock, valley oak acorns, peaches and almond fruits. (J469.106.w1)

  • This species relishes acorns. (B430.w2)

  • Grasses are the main part of the diet in fields. 

QUANTITY EATEN: --

STUDY METHODS: --

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Hibernation / Aestivation

Notes

  • Active year-round. (B147)

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Haematology / Biochemistry

Notes

HAEMATOLOGY: --

BIOCHEMISTRY: --

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Detailed Physiology Notes
(Summary information provided for pertinent species-specific data cross-referenced in WILDPro)

Notes

METABOLISM (TEMPERATURE):

Specific Sylvilagus audubonii Information

  • ."At ambient temperatures below 30 C, body temperature is 38.3 C. however, "body temperature equals ambient temperature of 41.9 C in summer and a predicted 42.9 C in winter." (J469.106.w1)

  • This rabbits has a high lethal body temperate of 44.8 C. (J469.106.w1)

  • "Its ability to reduce heat load and water loss enables it to thrive in desert environments." (B430.w2)

  • There is a shift upward of the thermal neutral zone from winter to summer, and an 18% decrease in basal metabolism. This rabbit has a relatively high evaporative cooling capacity. AT 41.4 C, 100% of metabolic heat production is dissipated by evaporative cooling. (J469.106.w1)

RESPIRATORY SYSTEM (RESPIRATION): --

CIRCULATORY SYSTEM (PULSE/HEART RATE): --

GASTROINTESTINAL SYSTEM (FAECES AND GUT MOTILITY):

General Information

  • Lagomorphs have digestive systems which are adapted for processing large quantities of vegetation. (B285.w5a)
  • Lagomorphs are well adapted for obtaining the greatest possible value from their food. They produce two types of fecal material: moist pellets and dry pellets. The moist pellets are expelled and then eaten (a behaviour known as coprophagy (B285.w5a)); this is done with little or no chewing, and as a result the majority of the food passes through the digestive tract twice (this is thought to have the same function as 'chewing the cud' in ruminants). The dry faecal pellets are not eaten. (B147)

Specific Sylvilagus audubonii Information

  • Faeces are deposited on logs, tree stumps and other low prominences, probably while these are being used as look-out posts. (J469.106.w1)

URINARY SYSTEM (URINE): --

CHROMOSOMES:

Specific Sylvilagus audubonii Information

  • 2 n = 42. (J469.106.w1)

MUSCULO-SKELETAL SYSTEM: --

SPECIAL SENSES AND VOCALISATIONS:

General Information

  • All lagomorphs use scent products secreted from special glands. (B285.w5a) These glands are located under the chins and in the groin, and are believed to play a key role in sexual communication, as well as in signalling social status in some gregarious species. (B285.w5b)
  • Whereas pikas tend to be more vocal, rabbits and hares rely strongly on scent rather than sound as a means of communication. (B285.w5b)
  • High-pitched distress squeals are emitted by leporids when captured by a predator, and specific alarm calls are produced in five rabbit species. (B285.w5b, B430.w2)
  • Some rabbit species thump the ground with their hind feet when faced with danger (B285.w5b, B430.w2); this reaction is thought to be a warning to nestlings underground. (B285.w5b)
  • The conspicuous white underside present on the tails of some rabbit species can act as a visual warning to other individuals when fleeing from a predator. These species tend to be found in more open habitats. (B285.w5b)

Sylvilagus spp. General Information

  • Rarely vocalise. (B285.w5c)
  • "Several species utter squeals and high-pitched calls of distress." (B147)

Specific Sylvilagus audubonii Information

  • Squeals have been heard when rabbit was removed from a trap, and from wounded rabbits. (J469.106.w1)
  • "Gupp" sounds, possibly a call response before nursing, were heard from young when the hair of the nest was touched. (J469.106.w1)
  • Thumping of the hind legs is used . (J469.106.w1)
  • The tail is held up with the white underside visible as an alarm signal while the rabbit is running for cover. (J469.106.w1)

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Behaviour

Feeding Behaviour

Notes

General Information
  • Lagomorphs are well adapted for obtaining the greatest possible value from their food. They produce two types of fecal material: moist pellets and dry pellets. The moist pellets are expelled and then eaten; this is done with little or no chewing, and as a result the majority of the food passes through the digestive tract twice (this is thought toe have the same function as 'chewing the cud' in ruminants). The dry pellets are not eaten. (B147)

Specific Sylvilagus audubonii Information

  • This species may forage in a small group. (B430.w2)
  • Habitat determines feeding sites. (B430.w2, J469.106.w1)
  • "In heavy cover adjacent to grasslands, much foraging takes place under the shelter of bushes. When feeding in open areas, the desert cottontail is very cautious. It moves slowly, with front feet forward and neck stretched out, hopping only when it must to reach food." (B430.w2)
  • In open areas, they feed by taking several mouthfuls of food, then elevate the head and chew. (J469.106.w1)
  • Generally they take the terminal portions of plants. (J469.106.w1)
  • "When feeding on low-growing grass, rabbits appear to extend the body along the ground. The neck is stretched out and the front feet edge forward. When food can no longer be reached, the hind feet are brought forward with a hop."
  • They arso often stand on their hind legs to feed, and will leave twigs cut at a characteristic 45 degree angle. (J469.106.w1)

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Parental Behaviour

Notes

General Information

  • Male leporids are not generally involved in care of the young. However, if adult females attack young leporids, males will intervene, a behaviour known as 'policing'. (B285.w5b)
  • Even maternal care of the young is not particularly prominent in leporids, hence this reproductive strategy is known as 'absentee parentism'. (B285.w5a)
  • Leporids demonstrate an unusual system of nursing; the young are suckled only briefly (often less than five minutes) just once every 24 hours. (B285.w5b)
  • It is thought that the lack of social contact between the mother and her young is a strategy which diminishes the chances of attracting the attention of predators. (B285.w5b)
  • The entrances to breeding tunnels are carefully re-sealed following each bout of suckling (B285.w5b)

Sylvilagus spp. General Information:

  • The females of most species of Sylvilagus dig nest holes, about 100-150 mm deep and 120 mm wide; sometimes slanted, and both lined and covered with soft plant fibres and the female's own fur, which she plucks from her underside.  (B147)
  • The female does not herself live in the nest. To feed the young she crouches over the nest, the kits climbing to the top of the nest to nurse. (B147)

Specific Sylvilagus audubonii Information

  • The females makes a nest, lined with fine grass, weeds and fur. (J469.106.w1)
  • The female will nurse the young within the nest or form, until the young are able to forage for themselves (at approximately two to three weeks of age). (B430.w2)
  • The female crouches over the nest for the young to suckle. (J469.106.w1)
  • Intervals as long as 30 and 31.5 hours have been recorded between nursings. Nursing occurred between 1300 and 1400 on one occasion and at 2000 hours on another occasion. (J469.106.w1)

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Social Behaviour / Territoriality / Predation / Learning

Notes

SOCIAL BEHAVIOUR:

General Information

  • Most North American leporid species are solitary, but congregations of these animals often occur in favoured feeding grounds. (B430.w2)
  • Rabbits are solitary to gregarious. (B430.w2)

Sylvilagus spp. General Information:

  • Most species within this genus are solitary. (B147)
  • May chase off other individuals if they approach too closely. (B147)
  • "Not colonial, but some species form social hierarchies in breeding groups." (B285.w5c)
  • "Cottontail behavior is stereotyped and fairly consistent with other rabbit species." (B605.5.w5)
Specific Sylvilagus audubonii Information
  • This species is not gregarious. (B430.w2, B605.5.w5, J469.106.w1)
  • Several individuals may forage together. (B430.w2)
    • As many as three females foraging together without any antagonistic behaviour has been observed. (J469.106.w1)
    • A male was seen to chase another male from a favoured feeding station on one occasion. (J469.106.w1)
  • "There have been no studies dealing directly with the behavior of Audubon's cottontails." (B605.5.w5)
  • Have been seen feeding alongside jackrabbits (Lepus sp.) and California ground squirrels (Sciuridae - Squirrels, Marmots etc. (Family)). (J469.106.w1)
PREDATION: 

Specific Sylvilagus audubonii Information

Predator Avoidance

General Information

  • Rabbits use dense cover to hide from predators. (B285.w5b)

Sylvilagus spp. General Information:

  • When under threat from a predator, cottontails sit completely still and remain quiet, even when closely approached. They are capable of staying like this for 15 minutes if necessary. (B147)

Specific Sylvilagus audubonii Information

  • This species will remain motionless when startled. (B430.w2)
  • May remain motionless if uncertain,but generally dash for cover when alarmed. (J469.106.w1)
POPULATION DENSITIES

Sylvilagus spp. General Information:

  • "Population levels vary markedly between species and from year to year, depending on climate, habitat type and other factors." (B605.5.w5)
  • Cottontails tend to be cyclic in abundance. (B605.5.w5)
  • "Habitat is the key to cottontail abundance." (B605.5.w5)
    • Desert species: normal densities are thought to be less than one rabbit per hectare. (B605.5.w5)

Specific Sylvilagus audubonii Information

  • San Joaquin Valley (California): 1.6 - 4.7 per hectare (varying density between years). (B147, J469.106.w1)
  • Northeastern Colorado: 16.3 per hectare (6.6 per acre). (B147, J469.106.w1)
  • Population densities may exceed 15 individuals per hectare. (B430.w2)
HOME RANGES AND DISTANCES TRAVELLED

Sylvilagus spp. General Information:

  • The home ranges of females are generally smaller than those of males. (B147)
  • These species have stable home ranges of a few hectares which overlap. (B285.w5c)
Specific Sylvilagus audubonii Information
  • Oregon: 0.4 to 6.1 hectares. (B147)
  • San Joaquin Valley (California): 3.2 - 3.6 hectares (8 - 9 acres) for both males and females. (B147, J469.106.w1)
  • Home range for this species is usually around 4 hectares, but may be even bigger depending upon the type and extent of available cover. (B430.w2)
  • Home range size may be the same as the size of the blackberry clump inhabited. (J469.106.w1)
  • Males: up to 6.1 hectares (15 acres); females perhaps 0.4 hectares (1.4 acres). (J469.106.w1)
  • Smaller foraging ranges noted for juveniles than for adults. (J469.106.w1)
  • Shifts in home range have been observed, possibly due to changes in available food or succulence. (J469.106.w1)
TERRITORIALITY

General Information

  • Ranges of individuals may overlap in favoured feeding grounds. (B285.w5b)

Sylvilagus spp. General Information:

  • Not territorial. (B285.w5c)

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Sexual Behaviour

Notes

General Information
  • All lagomorphs use scent products secreted from special glands. (B285.w5a) These glands are located under the chins and in the groin, and are believed to play a key role in sexual communication, as well as in signalling social status in some gregarious species. (B285.w5b)

Sylvilagus spp. General Information:

  • "Several males may come together during the breeding season and pursue an estrous female." (B147)

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Activity Patterns, Self-grooming and Navigation

Notes

ACTIVITY PATTERNS:

Sylvilagus spp. General Information:

  • Active year-round. (B147)
  • The majority of species move by characteristic bunny hopping. (B147)
  • It is thought that all species are capable of swimming. (B147)

Specific Sylvilagus audubonii Information

  • This species is usually inactive at temperatures above 26 C (80 F). (B605.5.w5, J469.106.w1)
  • "Temperature, rainfall, and wind affect behavior; this rabbit prefers to travel and forage on still days, or at night when temperatures dip below 26C (80F)." (B430.w2)
  • Still nights are preferred. (J469.106.w1)
  • This species will rest in a hide or burrow during hot days. (B430.w2)
  • In open locations, rest in a burrow while inactive, otherwise hide in forms (small cleared areas on the ground). (J469.106.w1)
  • The Desert cottontail may climb trees. (B605.5.w5)
  • It is thought that logs and tree stumps are used as lookout posts, as pellet piles often accumulate in these areas. (B430.w2, B605.5.w5, J469.106.w1)
  • Able to swim, with rapid strokes, moving the legs alternately. (J469.106.w1)
  • Climb brush piles and trees. (J469.106.w1)
  • While running, bound into the air to clear obstacles such as grass tufts. Usually travel in a zigzag pattern rather than a straight line. (J469.106.w1)
SELF-GROOMING: --
CIRCADIAN RHYTHM:

Sylvilagus spp. General Information:

  • Mostly nocturnal or crepuscular. (B147)
  • Cottontails are sometimes seen during daylight hours. (B147)
  • Active at night or during the day. (B285.w5c)

Specific Sylvilagus audubonii Information

  • This species is most active early in the morning and early evening. (B430.w2, B605.5.w5, J469.106.w1)
  • In late spring, active any time of day and night, but in winter active only at night, staying in thickets during the day. (J469.106.w1)
  • The daily timing of feeding periods is heavily dependent on the weather. They usually feed at dawn, but not if it is foggy or windy. (J469.106.w1)
  • They are more likely to vnture further from cover when it is dark. (J469.106.w1)
SPEED OF MOVEMENT:

Specific Sylvilagus audubonii Information

  • Recorded on one occasion at estimated 15 mph (24.13 kph). (J469.106.w1)
NAVIGATION:
  • Variable re-establishment following displacement: three rabbits returned home from distances of 960 - 1,341 m (3150 - 4400 ft), but 10 other rabbits remained at the release sites. (J469.106.w1)

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Habitat and Range

General Habitat Type

Notes

Specific Sylvilagus audubonii Information
  • Desert and steppe. (B51)
  • Desert. (B147, B430.w2)
  • This species is also found in woodlands and grasslands up to elevations of nearly 2,000 metres. (B430.w2)
  • Found in a diverse range of habitats. (B430.w2)
  • "Along rivers it is associated with riparian brush like willows, in uplands with pinyon-juniper stands, and in desert areas with sagebrush, rabbitbrush, and a variety of cacti." (B430.w2)
  • Habitat determines feeding sites. (B430.w2)
  • Arid areas. (B605.5.w5)
  • Deserts, grasslands and woodlands at lower elevations. (B605.5.w5)
  • In arid regions, the Desert cottontail is often associated with riparian zones. (B605.5.w5)
  • In areas where its range overlaps with that of the Sylvilagus nuttallii - Mountain cottontail, this species tends to inhabit desert valleys. (B430.w2)
  • Deserts, but also in heavy brush and willows along rivers in California, in fields with thick mats of weeds 1 metre high, and living around lumbar and brush piles and under old buildings. (J469.106.w1)
  • Shrubs as cover have been shown to be important in pinyon-juniper woodlands, with the best habitat having 170 - 220 shrubs or downed trees per hectare. (J469.106.w1)
  • Patures with moderate winter and moderate summer grazing pressure by cattle are preferred. (J469.106.w1)

Sylvilagus spp. General Information:

  • The presence of escape cover is an essential habitat requirement for these species. (B605.5.w5)

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Nests / Burrows / Shelters

Notes

Sylvilagus spp. General Information:

  • Cottontails are not thought to dig burrows. (B147)
  • Some species are known to make use of burrows made by other animals. (B147)
  • Also take shelter in brush piles and forms. (B147)
  • Several forms may be connected by flattened trails made through regular use of pathways. (B147)
  • "All species occupy burrows made by other animals or inhabit available shelter or hide in vegetation." (B285.w5c)
  • The females of most species of Sylvilagus dig nest holes, about 100 - 150 mm deep and 120 mm wide; sometimes slanted, and both lined and covered with soft plant fibres and the female's own fur, which she plucks from her underside.  (B147)
  • The female does not herself live in the nest. To feed the young she crouches over the nest, the kits climbing to the top of the nest to nurse. (B147)
Specific Sylvilagus audubonii Information
  • This species will rest in a hide or burrow during hot days. (B430.w2)
  • Females nurse their young within a nest or form. (B430.w2)
  • Nests made by females for their young were about 150 - 250 mm deep pear-shaped excavations with the diameter at the bottom abut 150 mm. There was a lining of fine grass and weeds, then of fur. Nsest were in various sites, depending on habitat. (J469.106.w1)
  • Burrows reported along rivers in California. (J469.106.w1)
  • Rest in thickets. (J469.106.w1)

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Distribution and Movement (Migration etc.)

Notes

Specific Sylvilagus audubonii Information
  • Found in central and southwestern USA, to central Mexico. (B51)
  • This species is found in the following areas within the USA:
    • Central Montana. (B285.w5c); north-central Montana. (B607.w20)
    • Southwest North Dakota. (B285.w5c, B607.w20)
    • North-central Utah. (B285.w5c, B607.w20)
    • Central Nevada. (B285.w5c, B607.w20)
    • Northern and central California. (B285.w5c, B607.w20)
  • It is also found within the following areas of Mexico:
  • "...northern California and western North Dakota to southern Baja California and central Mexico." (B147)
  • "The desert cottontail is typically found at lower elevations in the desert Southwest and arid intermountain West." (B430.w2)
  • This species is found in arid regions. In Death Valley (California), this species is found below sea level, and is known to live at elevations of at least 1,829 m in mountainous areas. (B605.5.w5)
  • "The species is found from near the Canadian border in Montana, south into central Mexico and from the Pacific coast of California, east into central Texas, Oklahoma, Kansas, Nebraska, South Dakota and North Dakota." (B605.5.w5)
  • In Death Valley, this species lives below sea level. (B430.w2)
  • "...widely distributed throughout the Southwest and Plains states." (B430.w2)
  • The distribution of the various subspecies is as follows:
    • Sylvilagus audubonii arizonae: "...southeastern California, southern Nevada, western Arizona, and western mainland Mexico south to about Quaymas." (B430.w2)
    • Sylvilagus audubonii audubonii: "...California, from a line between San Jose and Sonora north through the Sacramento Valley to about Redding." (B430.w2)
    • Sylvilagus audubonii baileyi: "...southeastern Montana, southwestern North Dakota, western South Dakota, Wyoming, except the extreme northwestern edge, western Nebraska, extreme northwestern and eastern Colorado, not including the central Rocky Mountains, extreme northeastern Utah, and northwestern Kansas." (B430.w2)
    • Sylvilagus audubonii cedrophilus: "...southwestern Colorado, except the central Rocky Mountains, northwestern and central New Mexico, southeastern Utah, and northwestern Arizona." (B430.w2)
    • Sylvilagus audubonii confinis: "...Baja California from about Camala south." (B430.w2)
    • Sylvilagus audubonii goldmani: "...southern mainland Mexico from about Navojoa south to about Mazatlan." (B430.w2)
    • Sylvilagus audubonii minor: "...southeastern Arizona, southwestern New Mexico, extreme southwestern Texas, and central Mexico as far south as Monterrey." (B430.w2)
    • Sylvilagus audubonii neomexicanus: "...southwestern Kansas, eastern New Mexico, and northwestern and central Texas from about Austin to the Apache Mountains." (B430.w2)
    • Sylvilagus audubonii parvulus: "...south-central Texas south to about Ciudad Madero on the coast of Mexico, then inland to about Las Herreras, then south to Mexico City." (B430.w2)
    • Sylvilagus audubonii sanctidiegi: "...extreme southwestern California from about Ventura south to about Colonet, Baja California." (B430.w2)
    • Sylvilagus audubonii vallicola: "...central California from about Mariposa south to Yermo and west and north along the coast to about San Jose." (B430.w2)

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Conservation

Species variation

Notes

Currently recognised subspecies include:
  • Sylvilagus audubonii audubonii: including Sylvilagus audubonii vallicola. (B607.w20)
  • Sylvilagus audubonii arizonae: including Sylvilagus audubonii laticinctus; Sylvilagus audubonii major; Sylvilagus audubonii rufipes; Sylvilagus audubonii sanctidiegi. (B607.w20)
  • Sylvilagus audubonii baileyi: including Sylvilagus audubonii neomexicanus. (B605.5.w5, B607.w20)
  • Sylvilagus audubonii confinis. (B605.5.w5, B607.w20)
  • Sylvilagus audubonii goldmani. (B605.5.w5, B607.w20)
  • Sylvilagus audubonii minor: including Sylvilagus audubonii parvulus. (B605.5.w5, B607.w20)
  • Sylvilagus audubonii warreni: including Sylvilagus audubonii cedrophilus. (B607.w20)

NB: names in non-bold font are reported as synonyms for that particular subspecies from the reference B607.w20.

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Conservation Status

Notes

WILD POPULATION - IMPORTANCE:

Specific Sylvilagus audubonii Information

  • Common. (B430.w2)
  • "In Mexico it is still common over much of its geographic range." (B605.5.w5)
  • The status of this species is monitored in many states. (B605.5.w5)

GENERAL LEGISLATION: --

CITES LISTING: --

RED-DATA LIST STATUS:

Specific Sylvilagus audubonii Information

  • IUCN - Lower Risk (least concern). (W2.Apr08.w75)

THREATS:

Specific Sylvilagus audubonii Information

  • Land clearings and cattle grazing. (B605.5.w5)

PEST STATUS / PEST POPULATIONS: --

CAPTIVE POPULATIONS: --

TRADE AND USE:

Specific Sylvilagus audubonii Information

  • The Desert cottontail is an important game species. (B605.5.w5)

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