CONTENTS

Living Organisms / Animalia / Craniata / Mammalia / Lagomorpha / Leporidae / Lepus / Species

Lepus insularis - Black jackrabbit (Click photographs/illustrations for full picture & further details)

INDEX - INFORMATION AVAILABLE

Alternative Names (Synonyms)

• Lepus edwardsi. (B607.w20)

Names for new-borns / juveniles

• Leveret. (B285.w5b)

Names for males

• Buck. (B285.w5d)

Names for females

• Doe. (B605.1.w1)

General Appearance

General Information

• All hares have well-furred feet. (B147)
• "The upper parts of the body are usually brown or grayish brown, and the underparts are paler or white." (B147)
• Some species of hare have black tips to their ears, and some have black fur on the upper side of their tail. (B147)

Specific Lepus insularis Information

• Moderate-sized species. (B605.4.w4)
• Basically black, such that it is conspicuous on both bare and vegetated areas: "resembles a short, charred stump." (J469.465.w1)

Newborn:

General Information

• Lepus spp. leverets are furred at birth. (B147, B285.w5b, B287)

Similar Species

• Distinguished from Lepus californicus - Black-tailed jackrabbit by its darker upperparts as well as shorter ears. (J469.465.w1)

Sexual Dimorphism

References

Species Authors & Referees

• See: DIRECTORY- Organisations working with Rabbits and their Relatives

• Rabbits, Hares and Pikas Status Survey and Conservation Action Plan
• See also: The Electronic Library- further reading for "Rabbits and their Relatives: Health & Management"

Husbandry Information

Notes

• --

Management Techniques

• Accommodation Design for Mammals
• Mammal Behavioural Requirements
• Food and Feeding for Mammals
• Mammal Handling & Movement
• Mammal Identification
• Preventative Medicine for Mammals
• Rearing of Mammals
• Reproductive Management of Mammals
• Management of Unwanted or Illegally Held Animals
• Hand-rearing Hares and Jack-rabbits (Lepus spp.)

Measurement & Weight

Notes

LENGTH
Adult:

General Lepus Information

• 400-700 mm. (B147)
• Males are usually smaller than females. (B147)
• 40-76 cm. (B285.w5c)

Specific Lepus insularis Information

• Total length 574 mm. (J469.465.w1)

Newborns: --

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

WEIGHT
Adult:

Specific Lepus insularis Information

• This species weighs approximately 2.5 kg. (B605.4.w4)

Newborns: --

GROWTH RATE --

Head and Neck

Notes

Note: There is very little data specific to this species so the details below are from general lagomorph and leporid information.

GENERAL HEAD STRUCTURE:
Adult:

General Information:

• All lagomorphs have large ears relative to their body size. (B285.w5a)
• Almost all Lepus species have long ears. (B147)

Specific Lepus insularis Information

• Ears (dry specimen, from notch) 105 mm. (J469.465.w1)

Newborn: --

DENTITION:
Adult:

General Information

• Rabbits and hares have a total of 28 teeth. (B285.w5a)
  • The dental formula for rabbits and hares is i 2/1, c 0/0, pm 3/2, m 3/3 x 2 = 28. (B147, B285.w5a)
  • This differs slightly in Pentalagus furnessi - Amami rabbit, with the molars sometimes being 2/3. (B147, B623.w3)
• 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:

General Information:

• Leverets are born with their eyes open. (B147, B285.w5b, B287)

Legs, Spine and Tracks

Notes

• All hares have well-furred feet. (B147)
• Almost all Lepus species have large hind feet. (B147)

Specific Lepus insularis Information

• Hind foot length 121 mm. (J469.465.w1)

Tail

Notes

• Leporids have a short tail. (B147)

General Lepus Information:

• 35-100 mm. (B147)
• Average: 58 mm. (B430.w2)
• Range: 48-76 mm. (B430.w2)
• 3.5-12 cm. (B285.w5c)

Specific Lepus insularis Information

• Tail length 96 mm. (J469.465.w1

Skin / Coat / Pelage

Notes

Adult: 

Specific Lepus insularis Information

• Upperparts: Glossy black, with the sides are grizzled reddish brown or dark buff. (B605.4.w4)
• Head: Top glossy black, sometimes with a few white hairs on the centre of the crown, and may be grizzled reddish brown or dark buff. Ring of grey around the eyes. (B605.4.w4, J469.465.w1)
• Ears/Sides of head: Dusky grey. (B605.4.w4) Ears blackish with grey grizzling, and on the inner side grey. (J469.465.w1)
• Shoulders/sides: dark buffy/cinnamon buffy. Forelegs and feet, upper surfaces as the sides, but more reddish. Hindlegs as sides of body, with the tops of the hin feet sometimes paler - dingy whitish. (J469.465.w1)
• Underparts: Dusky brown or dark cinnamon buff. (B605.4.w4)

Adult Colour variations:

General Lepus 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:

• Lepus spp. leverets are furred at birth. (B147, B285.w5b, B287)

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

Notes

The details below are from general lagomorph, leporid and Lepus information.

Skull

• 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

• Female Lepus spp. have three to five pairs of mammary glands, with an extensive mass of mammary tissue. (B147, B287)

Male reproductive tract

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

Digestive system

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

Natural Diet

Notes

Note: There is very little data specific to this species so the details below are from general hare information.

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 insularis Information

• Available vegetation includes "arid tropical and lower-Soneral shrubs and other plants". The main vegetation is cacti.(J469.465.w1)

QUANTITY EATEN: --

STUDY METHODS: --

Hibernation / Aestivation

Notes

Haematology / Biochemistry

Notes

HAEMATOLOGY: --

BIOCHEMISTRY: --

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

Notes

Note: There is very little data specific to this species so the details below are from general lagomorph and leporid information.

METABOLISM (TEMPERATURE): --

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 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 faecal pellets are not eaten. (B147)

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)

Feeding Behaviour

Notes

• 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 faecal pellets are not eaten. (B147)

Specific Lepus insularis Information

• No information available on the behaviour of this species. (B605.4.w4)

Parental Behaviour

Notes

• 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)

Specific Lepus insularis Information

• No information available on the behaviour of this species. (B605.4.w4)

Social Behaviour / Territoriality / Predation / Learning

Notes

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 insularis Information

• No information available on the behaviour of this species. (B605.4.w4)

Specific Lepus insularis Information

• Possible predators include only the few Falco sparverius - American Kestrel and Caracara cheriway - Caracara (Falconidae - Caracaras, Falcons (Family)) on the island. (J469.465.w1)

PREDATOR AVOIDANCE: 

• 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 are capable of running for greater distances than true rabbits (Sylvilagus sp.). (B147)

POPULATION DENSITIES:

General Lepus 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)

General Lepus Information

• "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)

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)

Sexual Behaviour

Notes

• 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)
• 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 insularis Information

• No information available. (B605.4.w4)

Activity Patterns, Self-grooming and Navigation

Notes

Note: There is very little data specific to this species so the details below are from general leporid information.

ACTIVITY PATTERNS:

General Information

• All the lagomorphs are terrestrial. (B147)

SELF-GROOMING: --

CIRCADIAN RHYTHM:

General Information 

• Hares and rabbits are generally at their most active at dusk or at night. (B430.w2)
• Hares are, on the whole, nocturnal species, although some are known to be more active at twilight, and others are most active during the cooler parts of the day. (B147)

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)

NAVIGATION: --

General Habitat Type

Notes

• Most Lepus species live in open grassy habitats. (B147, B285.w5c)
• Jackrabbits tend to be found in areas of sparse vegetation. (B147)

Specific Lepus insularis Information

• Found mainly in the valleys and on the lower slopes of the hills, up to 300 m. The vegetation includes "arid tropical and lower-Soneral shrubs and other plants". The main vegetation is various species of cacti. (J469.465.w1)

Nests / Burrows / Shelters

Notes

Note: There is very little data specific to this species so the details below are from general hare 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)

Distribution and Movement (Migration etc.)

Notes

• Restricted to Espiritu Santo Island, Gulf of California (Mexico) (off southeastern Baja California). (B147, B285.w5c, B605.4.w4, B607.w20, J469.465.w1)
• Introduced to Pichilinque Isand (nearby). (J469.465.w1)

Species variation

Notes

• Monotypic. (J469.465.w1)

Note:

• "This species is closely related to the black-tailed jackrabbit L.californicus [Lepus californicus - Black-tailed jackrabbit], but the jugal bone is heavier and there are sufficient differences in the skull to separate the black jackrabbit from both L.californicus on the adjacent mainland and from other subspecies (L.c. xanti, L.c.magdalenae) on nearby islands." (B605.4.w4)

Conservation Status

Notes

WILD POPULATION - IMPORTANCE:

Specific Lepus insularis Information

• Although not presently in any danger, suggestions have been made that the establishment of another population of this species on a nearby island would be a wise move to ensure its future stability. (B605.4.w4, J469.465.w1)

GENERAL LEGISLATION: --

CITES LISTING: --

RED-DATA LIST STATUS:

Specific Lepus insularis Information

• IUCN - Lower Risk (near threatened). (W2.Apr08.w21)

THREATS:

Specific Lepus insularis Information

• Presently no threats to the population. Despite its restricted distribution, the island on which this species lives is not likely to be inhabited, and as such the species is not currently in any danger. (B605.4.w4, J469.465.w1)

PEST STATUS / PEST POPULATIONS: --

CAPTIVE POPULATIONS: --

TRADE AND USE: --