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

Lepus alleni - Antelope jackrabbit (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)

  • Allen's hare. (B430.w2)
  • Allen's jackrabbit. (B430.w2)
  • Blanket jack. (B430.w2)
  • Burro jack. (B430.w2)
  • Jackass rabbit. (B430.w2)
  • Mexican jackrabbit. (B430.w2)
  • Saddle jack. (B430.w2)
  • Wandering jackrabbit. (B430.w2)
  • White-sided jackrabbit. (B605.4.w4)
  • Lepus palitans. (B607.w20)
  • Lepus alleni tiburonensis. (B607.w20)
  • Lepus alleni alleni. (B430.w2, B605.4.w4, B607.w20)

  • Lepus alleni palitans. (B430.w2, B605.4.w4, B607.w20)

  • Lepus alleni tiburonensis. (B430.w2, B605.4.w4, B607.w20)

Names for new-borns / juveniles

  • Leveret. (B285.w5b)

Names for males

Names for females

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General Appearance

Specific Lepus alleni Information

Adult:

  • This is one of the largest of the Lepus species. (B147)
  • It is sandy in colour, with a white underside. (B605.4.w4)
  • The Antelope jackrabbit gets its name from the fact that the flash of white displayed on its rump whilst running is similar to that of the Antilocapra americana - Pronghorn. (B430.w2)
  • This species has large ears (B430.w2, B605.4.w4), which are whitish in colour, and are devoid of fur except for the edges and tips which have long fringes of white hair. (B430.w2) The ear tips, unusually for a hare, are not black. (B605.4.w4)

Newborn:

  • Fully haired with open eyes. Slightly darker than the adult, with white posterior edges to the ears and a small white sport in the middle of the forehead. (J469.424.w1)

Similar Species

Specific Lepus alleni Information

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

Specific Lepus alleni Information

  • This species is relatively large compared to other hare species found in North America. (B430.w2, B605.4.w4)

LENGTH
Adult:

  • There is no significant sexual dimorphism in this species. (B430.w2, B605.4.w4)
  • Average: 622 mm. (B430.w2)
  • Range: 553 - 670 mm. (B430.w2)
  • Males: 553 - 670 mm, average 619 mm. (J469.424.w1)
  • Females 597-660 mm, average 625 mm. (J469.424.w1)

Newborns: --

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

WEIGHT
Adult:

  • Average: 3,800 g. (B430.w2)
  • Range: 2,700-5,900 g. (B430.w2)
  • Average 3.93 kg for males and females combined in one study. (J469.424.w1)
  • In Arizona this species has an average weight of 3.63 kg, with a range of 2.7-5.9 kg. (B605.4.w4)
    • Males 2.70 - 4.73 kg, average 3.69 kg. (J469.424.w1)
    • Females 2.88 - 5.85 kg, average 4.05 kg; excluding pregnant females, 2.88 - 4.50 kg, average 3.60 kg. (J469.424.w1)

Newborns:

  • Three neonates obtained by caesarean section weighed 108, 1.3.5 and 90 g. (J469.424.w1)
  • One neonate was 184 g. (J469.424.w1)

GROWTH RATE

  • Weaning mass: 3.0 kg (sd = 0.34; sample size = 13). (B287)

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Head and Neck

Notes

GENERAL HEAD STRUCTURE:
Adult:

Specific Lepus alleni Information 

  • The Antelope jackrabbit has an ear length of 138-173 mm (B147, B605.4.w4) with an average of 162 mm. (B605.4.w4)
    • Males 146 - 173 mm average 163 mm; females 138 - 173 mm, average 161 mm. (J469.424.w1)
  • This species has large ears (B430.w2, B605.4.w4), which are whitish in colour, and are devoid of fur except for the edges and tips which have long fringes of white hair. (B430.w2)
  • The ears can be more than 21 cm long and 10 cm wide. (J469.424.w1)

Newborn: --

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)

Specific Lepus alleni information

  • P3 is relatively small for the size of the hare. (J469.424.w1)

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: 

Specific Lepus alleni Information

  • Born with their eyes open. (J469.424.w1)

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Legs, Spine and Tracks

Notes

General Information
  • All hares have well-furred feet. (B147)

Specific Lepus alleni Information

  • The Antelope jackrabbit has large hind feet, averaging 140 mm but ranging from 127-150 mm. (B605.4.w4)
    • Males range 121-133 mm, average 128 mm; females 121-133 mm, average 127 mm. (J469.424.w1)

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Tail

Notes

General Information
  • Leporids have a short tail. (B147)

Length

Specific Lepus alleni Information

  • Average: 58 mm (Range: 48-76 mm). (B430.w2)
  • Males range 52 - 70 mm, average 57 mm; females 48 - 76 mm, average 59 mm. (J469.424.w1)
  • 3.5-12 cm. (B285.w5c)

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Skin / Coat / Pelage

Notes

Adult:

Specific Lepus alleni Information

  • The Antelope jackrabbit gets its name from the fact that the flash of white displayed on its rump whilst running is similar to that of the Antilocapra americana - Pronghorn. (B430.w2)
  • This species has a yellowish-brown upper body, strongly mixed with black. (B430.w2)
  • "The sides, including the outer side of the limbs, hips, and rump, are white with fine black points on some of the hairs. The chin, throat, undersurface, inner sides of the forelegs, and tail are white." (B430.w2)
  • Pelage is pale and sandy-coloured, with white sides and underside. (B605.4.w4)
  • Darker in winter than in summer. (J469.424.w1)
  • It does not have black ear tips - unlike most other hares. (B605.4.w4)

Adult Colour variations:

General Information 

  • Some Lepus species moult into a white winter pelage (B147, B605.4.w4), the timing of which depends upon the number of daylight hours. (B147)
  • "All species that turn white in winter undergo two molts per year. Some species that molt twice, however, do not have a white winter pelage." In these species, the winter pelage is grey, whereas the summer fur is brown. (B147)

Newborn / Juvenile:

Specific Lepus alleni Information

  • Slightly darker than the adult, with white posterior edges to the ears and a small white sport in the middle of the forehead. (J469.424.w1)
  • Newborn Antelope jackrabbits do not have a white rump. (B430.w2)

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

Notes

Skull

General Information

  • Leporids have an arched skull with a slight constriction between the orbits. (B147)
  • Lepus species have a skull that is lighter than the skull of rabbit species. (B605.4.w4)
Female reproductive tract

Specific Lepus alleni information

  • Three pairs of mammary glands, one pectoral and to abdominal; these are easily visible only when the female is lactating. (J469.424.w1)
Male reproductive tract

General Information

  • Males lack a baculum (B147)
  • Testes are in the scrotum located in front of the penis (B147)
Digestive system

General Information

  • The largest part of the digestive tract is the caecum; this has a capacity up to ten times that of the stomach. (B147)
Scent glands

Specific Lepus alleni Information

  • Both male and female have rectal glands, either side of the anus, about 12 mm deep, with a wide external opening, secreting a substance with a strong musky odour. (J469.424.w1)

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Life Stages / Natural Diet / Physiology

Life Stages

Notes

BREEDING SEASON:

Specific Lepus alleni Information

  • The breeding season for this species runs from late December through to September. (B287, B430.w2, J469.424.w1)
    • Peaks occur in spring and mid-summer. (J469.424.w1)
  • In Arizona, breeding occurs throughout the year, except in November. It was found that the proportion of pregnant females showed peaks which correlated with rainfall. Litter size was also found to correlate with rainfall. (B605.4.w4)
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)
  • Gestation for Lepus species varies, but can be up to 50 days. (B285.w5c)

Specific Lepus alleni Information

  • Gestation in this species is approximately six weeks in length. (B430.w2, J469.424.w1)
  • In Arizona, pregnant females were found from January to October. (B287)
PARTURITION / BIRTH:

General Information

  • Leverets are precocial and are born into surface-depression forms. (B285.w5b)
  • Females give birth to their young in open areas, or in a shallow depression in the ground. (B147)

Specific Lepus alleni Information

  • As with all hare species, Antelope jackrabbit young are precocial. (B430.w2)
  • Newborn Antelope jackrabbits do not have a white rump. (B430.w2)
Neonatal / Development:

General Information

  • Leverets are precocial; they are born fully furred, with open eyes, and are able to move about soon after birth. (B147, B285.w5b, B287)
  • Young are only suckled briefly once every 24 hours. (B285.w5b)
  • Approximately three days after birth, leverets disperse to separate hiding locations. Leveret litter-mates will regroup for a brief suckling bout at a particular location at precisely defined intervals. Such regrouping often takes place around sunset. (B285.w5b)

Specific Lepus alleni Information

  • Precocial. Fully haired, eyes open, and able to hop at birth. (J469.424.w1)
  • At, or shortly after giving birth, the female scatters her young. She then returns to nurse them at night time. (B430.w2)
  • Weaning mass: 3.0 kg (sd = 0.34; sample size = 13). (B287)
LITTER SIZE:

Specific Lepus alleni Information

  • On average, Antelope jackrabbits have two offspring per litter, though the number can range from one to five. (B430.w2)
  • Litter size has been reported to vary between 1.5 and 3.1, with a mean of 2.1. (B605.4.w4)
  • Range: 1 to 5 young per litter. (B287, B605.4.w4, J469.424.w1)
    • Arizona: 1 - 5, average 1.93. (J469.424.w1)
  • 1.94 embryos; mode = 1,2; Range is between one and five (Sample size = 124 females). (B287)
  • Three embryos (Sample size = 1 female); Six embryos (Sample size = 1 female). (B287)
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 they have given birth. (B285.w5a)

Specific Lepus alleni Information

  • A female can produce up to three or four litters per year. (B430.w2, J469.424.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)
SEXUAL MATURITY:

Specific Lepus alleni Information

  • Age of maturity has not yet been ascertained, but females of this species are thought to breed within a year of being born. (B605.4.w4)
  • Reach breeding age in their second year. (J469.424.w1)
MALE SEASONAL VARIATION: 

Specific Lepus alleni Information

  • The testes are generally found in the scrotum during the breeding season, while they are in the body cavity in mid winter. (J469.424.w1)
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)
  • "Only a minority of hares survive their first year in the wild, though survivors can reach 5 years; in captivity, hares can live to 6 or 7 years." (B285.w5c)

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Natural Diet

Notes

NATURAL DIET:

General Lepus Information

  • Hares mainly eat grasses and herbaceous plants, but do also feed on twigs, buds and bark. (B147)

  • Isolated cases have been reported of hares capturing and eating voles and young lagomorphs. (B147)

Specific Lepus alleni Information

  • This species browses on mesquite (Prosopis). (B430.w2)

  • The Antelope jackrabbit "lives on dry valley slopes distant from water sources, and if water is available, it does not drink." (B430.w2)

  • The bulk of its diet is made up of:

    • Green grass.

    • Other green vegetation.

    • Various species of cactus.

    (B430.w2)
  • Antelope jackrabbits consume highly succulent vegetation, and as drought conditions worsen their intake of cactus increases. (B430.w2)

  • "Antelope jackrabbits seek minerals by digging into and biting the soil." (B430.w2)

  • Following the two rainy seasons, Antelope jackrabbits eat fresh grass, switching to mesquite and cactus during the dry season. (B605.4.w4)

  • "Throughout the year, the antelope jackrabbit consumes 45% grass and 36% mesquite, compared with 24% and 56% respectively, for black-tailed jackrabbit [Lepus californicus - Black-tailed jackrabbit] in the same region." (B605.4.w4)
  • There is no evidence that this species needs to drink water; it appears to take in sufficient water with its food - mesquite and cactus. (J469.424.w1)
  • Weeds are selected first, followed by grass and browse. (J469.424.w1)
  • Mesquite 36%, grass 45%, remainder other foods. (J469.424.w1)
  • Soil is eaten for minerals. (J469.424.w1)

QUANTITY EATEN:

Specific Lepus alleni Information

  • Average 175.5 g forage per day (laboratory data). (J469.424.w1)
    • Alfalfa hay and rolled barley 126 g/day; air-dried natural forage, 167 g; air-dry green forage, 171 g: 5.8, 6.1 and 6.5% of bodyweight respectively. (J469.424.w1)

STUDY METHODS:

Specific Lepus alleni Information

  • Laboratory observations, stomach contents. (J469.424.w1)

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Hibernation / Aestivation

Notes

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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 Lepus alleni Information

  • Average rectal temperature 39.2 C (range 37.6 - 39.9 C). Maximum survivable temperature 43.0 - 44.1 C (43.7 C) and lethal temperature 45.4 C (range 44.9 - 45.9 C). (J469.424.w1)
    • At ambient temperature of 39 C, body temperature reaches about 40.3 C. (J469.424.w1)
  • This hare can maintain a stable body temperature for up to four hours in ambient temperatures of 51 C. (J469.424.w1)
  • It is thought that this species utilises its large ears as sites of heat exchange, allowing the animals to remain cool. (B430.w2)
  • The ears, which can be more than 21 cm long and 10 cm wide, increase the body surface area by about a quarter and are potentially significant heat exchangers by conduction, convection and radiation. Blood flow changes in the ears may affect heat conduction. (J469.424.w1)
  • Blood flow through the ears is increased when external conditions permit increased heat loss through this means, with immediate vasoconstriction when conditions do not allow such loss, thereby reducing heat gain via the ears. (J469.424.w1)
  • At high ambient temperatures the main method of heat loss used is evaporation. While ambient temperature is below 20 C (i.e. 18 C below body temperature), evaporation is responsible for just 8 - 10% of heat loss, increasing to about 50% when ambient temperature reaches just 5% below body temperature and 100% when ambient temperature is the same as body temperature. (J469.424.w1)
  • When ambient temperatures are below 25 C, water is lost at 0.06% body mass/hour. At higher ambient temperatures water loss increases, reaching 0.9% body mass/hour at 45 C and about 1.3% at 51 C. (J469.424.w1)

RESPIRATORY SYSTEM (RESPIRATION): --

CIRCULATORY SYSTEM (PULSE/HEART RATE): --

GASTROINTESTINAL SYSTEM (FAECES AND GUT MOTILITY):

General Information

  • Lagomorphs are well adapted for obtaining the greatest possible value from their food. They produce two types of faecal 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 pellets are not eaten. (B147)
  • Lagomorphs have digestive systems which are adapted for processing large quantities of vegetation. (B285.w5a)

Specific Lepus alleni Information

  • The digestive powers of this species have been described as "rapid and efficient". (B430.w2, J469.424.w1
  • It is thought that food passes through the entire digestive system in approximately 12 hours. (B430.w2, J469.424.w1)
  • Average 522 faecal pellets produced daily; these are about 6 - 7 mm diameter, nearly black in colour (while feeding on dried Bouteloua aristidoides (needle grama). (J469.424.w1)

URINARY SYSTEM (URINE): --

CHROMOSOMES: 

  • All the Lepus species have 48 chromosomes. (B605.4.w4)

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 chin 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. (B285.w5b, B430.w2)
  • The North American leporids have large ears with highly-developed hearing, an adaptation which allows them to detect predators when foraging in open habitats. (B430.w2)
  • Hares communicate with each other by drumming their feet. (B147)
  • Deep grumbling has been reported in Lepus species, and shrill calls are emitted when the animal is in pain. (B285.w5c)
  • "When seeking the young for nursing, females call the young and are answered." (B147)

Specific Lepus alleni Information

  • The Antelope jackrabbit very rarely vocalises. (B430.w2)
  • "They are silent except for the usual distress cry, grunts and "chuck" calls." (B605.4.w4)
  • Loud, often continuous cries when injured or caught. Otherwise generally silent but growling or grunting and a rapid "chuck, chuck, chuck" have been heard. (J469.424.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 faecal 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 to have the same function as 'chewing the cud' in ruminants). The dry pellets are not eaten. (B147)

Specific Lepus alleni Information

  • "When browsing on mesquite (Prosopis) it rears up on its hind feet, its forefeet hang limp, and its ears flop freely. Attempting to reach higher, it stands on its toes and places its forepaws on branch to crop off leaves, bark, or buds." (B430.w2)
  • In order to prevent dehydration in arid desert habitats, the Antelope jackrabbit feeds on succulent plants such as cactus and yucca. (B285.w5c)
  • Where sources of food and cover are separate within the habitat, this species has been known to make round trips of 10 miles from desert to feed on alfalfa. (B605.4.w4)
  • Antelope jackrabbits dig into and biting the soil forminerals. (B430.w2, J469.424.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)

General Lepus Information

  • Leverets remain hidden within dense vegetation, and the female visits them in order to nurse them. (B147)
  • Females give birth to their young in open areas, or in a shallow depression in the ground. (B147)
  • Young are only suckled briefly once every 24 hours. (B285.w5b)
  • Approximately three days after birth, leverets disperse to separate hiding locations. Leveret litter-mates will regroup for a brief suckling bout at a particular location at precisely defined intervals. Such regrouping often takes place around sunset. (B285.w5b)

Specific Lepus alleni Information

  • The female produces a nest for her young, under covering vegetation, lined with her own fur. (J469.424.w1)
  • The female returns at night to suckle her young. (J469.424.w1)
  • Nests which have been located contained one or two leverets; it has been suggested that the female scatters her young. (J469.424.w1)
  • "The duration of parental care is short; the young hares become independent in a matter of days." (B430.w2)

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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)
  • Hares are generally solitary animals. (B430.w2)
  • With the exception of the mating season (B147), most Lepus species are solitary. (B147, B285.w5c)
  • Hares communicate with each other by drumming their feet. (B147)

Specific Lepus alleni Information

  • It is thought that a dominance hierarchy exists within this species, as with other Lepus species, but no recent behavioural studies have been conducted. (B605.4.w4)
  • Males sometimes fight, standing on their hind legs and hitting each over very rapidly; usually the winning male then chases the other individual. Wounds, including ear wounds, from such fights are not uncommon. (J469.424.w1)
  • May be seen alongside (even running or sitting together) Lepus californicus - Black-tailed jackrabbit. (J469.424.w1)

PREDATION:

Specific Lepus alleni Information

PREDATOR AVOIDANCE:

General Information

  • Hares will run out into open areas and use their speed in order to avoid predators. (B285.w5b, B605.4.w4)
  • Speeds of up to 72 km/h (45 mph) have been reported for hares. (B285.w5b)
  • "Instead of seeking cover, hares rely on their well-developed running ability to escape from danger: also on camouflage, by flattening on vegetation." (B285.w5c)
  • Jackrabbits can avoid predators by crouching against the ground in any available cover. (B147)
    • Jackrabbits remain well hidden when crouching down in dense cover, but are often highly conspicuous when sitting up being vigilant or when running. (B147)
  • Jackrabbits are capable of running for greater distances than true rabbits (Sylvilagus sp.) (B147)

Specific Lepus alleni Information

  • White fur on the sides and rump produces a 'flash' display when the animal is in flight. Lepus callotis - White-sided jackrabbit also demonstrates this escape behaviour. (B605.4.w4)
  • "When it runs, a conspicuous white area is displayed on the rump. This white area appears to shift each time the jackrabbit turns, the white being kept toward the observer." (B430.w2)
  • If approached, the ears may be slowly lowered, reducing visibility. If the jackrabbit chooses concealment rather than flight, it hunches down, ears tight against the back. (J469.424.w1)

POPULATION DENSITIES:

General Information

  • Drastic, cyclic population density fluctuations occur in northern Lepus species. (B147)
  • Predator population cycles follow Lepus cycles; once predator populations have crashed, and vegetation has had the chance to regenerate, hare population numbers are able to start increasing once more. (B147)

Specific Lepus alleni Information

  • Population density is usually approximately 0.5 per hectare. However, at times the hares become so abundant that between 12 and 15 can be seen simultaneously. (B430.w2)
  • Population densities of 0.53 hares per hectare have been recorded on mesa type vegetation; these densities are the highest found in this species. It should be noted that the sympatric Lepus californicus - Black-tailed jackrabbit is found in highest population densities in semi-desert. (B605.4.w4)
  • 0.3 - 0.5 hares per hectare, higher in undisturbed areas of mesquite than in disturbed habitat. (J469.424.w1)
  • Groups of two to six individuals have been reported frequently; groups of up to 25 individual Antelope hares have been seen also. (B605.4.w4)
  • Antelope jackrabbit populations are not cyclic, and appear to be stable. (B605.4.w4)

HOME RANGES AND DISTANCES TRAVELLED:

General Information (Lepus)

  • "Habitat type has a marked effect on home-range size within each species, but differences also occur between species." (B285.w5c)
  • Lepus species vary greatly in their home range sizes, with some species having home ranges of only 4-20 hectares, and others exceeding 300 hectares. (B285.w5c)
  • Areas within a couple of metres of forms may be defended, but home ranges often overlap, often with common feeding grounds. (B285.w5c)

Specific Lepus alleni Information

  • The average home range for this species is 643 hectares. (B430.w2)
  • Home range is thought to vary vastly with habitat type, from 500 square feet to several miles in diameter. (B605.4.w4)

TERRITORIALITY:

General Information

  • The majority of hares and rabbits are non-territorial; some hares occupy home ranges of up to 300 ha (740 acres). Ranges of individuals may overlap in favoured feeding grounds. (B285.w5b)

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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)
  • Male Lepus become bolder during the mating season, and engage in fights with other males, and pursue females. (B147)
  • Male Lepus fight by using boxing motions with their forefeet and kicking with their hind feet. (B147)
  • Males often bite and kick the females, often leading to serious injury. (B147)

Specific Lepus alleni Information

  • This is a promiscuous species. (B605.4.w4)
  • Males pursue females, and box with other males. (B605.4.w4)
  • Copulation may be preceded by chasing and "vigorous combat accompanied by continuous growling" and may be followed by the female chasing the male. Copulation is similar to that seen in Oryctolagus cuniculus - European rabbit. (J469.424.w1)

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Activity Patterns, Self-grooming and Navigation

Notes

ACTIVITY PATTERNS:

  • All the lagomorphs are terrestrial. (B147)

Specific Lepus alleni Information

  • Uses 'shelter forms' (small depressions within the ground or vegetation) to rest in during the day. Or may simply rest next to a plant. (B430.w2, J469.424.w1)
  • This rabbit always seeks shade in the hot seasons. (J469.424.w1)
  • When resting, the ears lie along the back. When disturbed, the jackrabbit rises to a leaping posture, ears becoming erect. (J469.424.w1)
  • Running, it moves nearly horizontally for several leaps, then may give a higher leap. particularly in areas where vegetation may obstruct vision. When starting to run, the first few leaps may be on the hind legs only. (J469.424.w1)
  • When moving in a leisurely manner this jackrabbit does not show white flashes on its sides, but when running away there is a conspicuous white area on the rump which appears to shift from side to side, always on the side facing the observer. This effect is formed by a combination of the jackrabbit's zigzag running and muscular movements of the skin. (J469.424.w1)

SELF-GROOMING: --

CIRCADIAN RHYTHM:

Specific Lepus alleni Information

  • This species is nocturnal and crepuscular, (B430.w2, B605.4.w4, J469.424.w1) and most frequently feeds in the evening and early morning. (B605.4.w4)

SPEED OF MOVEMENT:

General Information

  • The North American leporids are able to escape predators by taking instant flight at high speed. (B430.w2)
  • Leporids can run at speeds of up to 80 km/hr. (B147)
  • Jack rabbits "run rapidly and for greater distances than the true rabbits (Sylvilagus) that occupy much the same range. Unlike the latter, jack rabbits make rather long, high leaps." (B147)

Specific Lepus alleni Information

  • Jackrabbits move in long, high leaps. (B147)
  • This is thought to be the fastest of the Lepus species, and can run at speeds of up to 72 km/hr. (B430.w2, J469.424.w1)

NAVIGATION: --

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Habitat and Range

General Habitat Type

Notes

Specific Lepus alleni Information

  • This species is found in a variety of habitats. (B430.w2, J469.424.w1)
  • Antelope jackrabbits seems to prefer areas where grasses, mesquites and catclaws (Acacia) are plentiful, yet are also found in deserts which have little grass coverage. (B430.w2)
  • The Antelope jackrabbit "lives on dry valley slopes distant from water sources, and if water is available, it does not drink." (B430.w2)
  • This species seems to favour grassy slopes located at moderate elevations (B605.4.w4, J469.424.w1), as well as "the cactus belt, creosote bush desert and valley bottoms." (B605.4.w4)

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Nests / Burrows / Shelters

Notes

General Information
  • Hares tend to reside in caves or crevices in rocks. (B430.w2)
  • Lepus species do not usually dig burrows or live in them, favouring fleeing rather than hiding as a mode of escape. (B147)
  • The majority of hares rest underneath vegetation, generally lying within shallow dips in the ground (soil, snow or grass) known as 'forms'. (B147)
  • The majority of Lepus species live on the surface, but some do dig burrows or use tunnels and holes made by other animals. (B285.w5c)
  • Uses 'shelter forms' (small depressions within the ground or vegetation) to rest in during the day. Or may simply rest next to a plant. (B430.w2)

Specific Lepus alleni Information

  • "This jackrabbit does not have burrows, but it may have nests beneath the ground level with some hair as lining. (B430.w2, J469.424.w1)
  • There are fewer jackrabbits than there are forms, and one individual was seen to make use of the same form on at least three separate occasions. (B605.4.w4)
  • Shelter forms (average 28 - 46 cm long, 8 - 15 cm wide) are usually under cover such as mesquite, cactus, hackberry or catclaw. Sometime dig out shelter forms into a shallow depression or a deeper excavation, deepest under the hindquarters. It is thought each is used for a few days. (J469.424.w1)
  • A nest under beargrass, containing two leverets, was round, lined with the mother's fur, and covered with bits of beargrass, "providing excellent concealment". (J469.424.w1)

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Distribution and Movement (Migration etc.)

Notes

  • Found in northwest Mexico and southern Arizona (B51, B147) as well as Tiburon Island (Gulf of California). (B147, B285.w5c,  B430.w2, B607.w20)
  • "Antelope jackrabbits inhabit the desert plains of southern Arizona southward into northern Nayarit, Mexico." (B430.w2)
  • Found at elevations from near sea level (Mexico) to 1,500 metres (southern Arizona). (B430.w2)
  • This species lives in southern New Mexico, southern Arizona to north Nayarit (in Mexico). (B285.w5c)
  • The Antelope jackrabbit is found in south-central Arizona (USA) to north Nayarit (Mexico). (B607.w20)
  • The distribution of the Antelope jackrabbit is not thought to have altered significantly since 1959. (B605.4.w4)
  • "It occupies the lower Sonoran life zone (from sea level to 1,200 m) in south Arizona and a coastal strip of northwest Mexico, 100-300 km wide, south to 22oN. Marginal records for Arizona are: 35 miles East of Florence; Cascabel; 7 miles North of Fort Huachua; Casa Grande; and Queen Creek, and there is one record for Yuma County." (B605.4.w4)
  • Lepus alleni alleni (B430.w2, B605.4.w4) - south-central Arizona and most of Sonora, Mexico (B430.w2); "South Arizona to about 28o N in Sonora." (B605.4.w4)
  • Lepus alleni palitans (B430.w2, B605.4.w4, B607.w20) - southern Sonora to northern Nayarit, Mexico (B430.w2); Sinaloa. (B605.4.w4)
  • Lepus alleni tiburonensis (B430.w2, B605.4.w4, B607.w20) - Tiburon Island, Gulf of California, Sonora, Mexico (B430.w2); this subspecies is restricted to Tiburon Island (Gulf of California). (B605.4.w4)

Geographic Sympatry

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Conservation

Species variation

Notes

  • Despite their name, jackrabbits are, in fact, true hares. (B147)

Subspecies include:

  • Lepus alleni alleni (B430.w2, B605.4.w4, B607.w20); including Lepus alleni palitans. B607.w20)
    • Lepus alleni palitans was formerly considered a separate subspecies. (B430.w2, B605.4.w4)
  • Lepus alleni tiburonensis (B430.w2, B605.4.w4, B607.w20)

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Conservation Status

Notes

WILD POPULATION - IMPORTANCE:

  • Common species. (B430.w2)
  • The number of Antelope jackrabbits present in areas of southern Arizona has significantly declined over recent years. This population decrease has occurred in areas where Lehmann lovegrass (Eragrostis lehmanniana) has been introduced and has subsequently replaced the native vegetation which the hares rely upon. (B430.w2)
  • Due to being adapted to living in open areas, hares have benefited from the activities of humans which have caused the decline of forested areas. (B605.4.w4)
  • In Arizona, this species is viewed as a common, non-game mammal. (B605.4.w4)
  • "Their status in Mexico requires investigation." (B605.4.w4)

GENERAL LEGISLATION: --

CITES LISTING: --

RED-DATA LIST STATUS:

  • IUCN - Lower Risk (least concern). (W2.Apr08.w4)

THREATS:

PEST STATUS / PEST POPULATIONS:

  • Antelope jackrabbits are frequently hunted as pest species on stock range, along with Black-tailed jackrabbits. There is no bag limit, and no close season. (B605.4.w4)

CAPTIVE POPULATIONS: --

TRADE AND USE:

  • Various Lepus species are consumed by humans. (B147)
  • Lepus fur is often used in the manufacture of felt, and for lining clothes such as gloves. (B147)

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