Leporidae

Very few species of leporids communicate through auditory methods, as most rely on their senses of sight and smell for intraspecific communication. However, certain species (e.g., volcano rabbits) rely heavily on vocalizations for intraspecific communication. Though leporids are typically silent, they still posses a highly developed and acute sense of hearing and emit high pitched distress calls when captured by a predator. For example, European rabbits, brush rabbits, and Audubon's cottontails are known to thump the ground with their hind feet to warn conspecifics of potential danger (e.g., approaching predators). Many leporids have white fur on the ventral surface of their tail, which they silently wave at conspecifics to warn of a predator's presence.

Leporids possess large, protruding eyes that are laterally positioned near the apex of the skull. The position and protrusion of the eyes help them detect predators over a wide visual arc and aid in overcoming the low light availability during crepuscular and nocturnal conditions, during which they are most active.

All Leporids have scent glands in the groin, cheeks, and under the chin that are used to rub pheromones on their coat during grooming. These glands and the pheromones they produce likely play an important role during mating. Glandular activity in male leporids, specifically the amount of pheromone produced and its degree of pungency, is correlated with testicle size. It has been suggested that pheromones serve as a status marker that identify one's position in the social hierarchy.

Communication Channels: visual ; acoustic ; chemical

Other Communication Modes: pheromones ; scent marks ; vibrations

Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical

Most leporid species are polygynandrous. During mating season males and females form small groups in which males compete for access to estrus females and establish a social hierarchy. European Rabbits serve as an exception as they are highly social and have established hierarchies prior to mating season. Males find and attract mates by flagging their tail, involuntary urination, and rubbing against the female prior to copulation. Both sexes have multiple mates and females mate soon after giving birth or while carrying a litter. Gestation typically lasts longer in hares than in rabbits. For example, gestation lasts approximately 55 days in mountain hares and 30 days in European rabbits. Hares are born in a precocial state, fully furred with their eyes open, and are able to run a few hours after parturition. Rabbits are born in an altricial state and are able to see a few days after parturition.

Mating System: polygynandrous (promiscuous)

Some members of the family Leporidae do not have a specific breeding season while others breed during spring and summer. Female ovulation is induced during copulation, about twelve hours after insemination, and females can come into estrus at various times throughout the year. Many species mate immediately after or just before parturition, as females are able to carry two different litters at once (i.e., superfetation). Leporids have high reproductive potential and can produce several litters per breeding season, with several young per litter. Litters usually consist of 2 to 8 young with a maximum of 15 young rabbits (kittens) or hares (leverets) per litter. Resource abundance and quality play a major role in fecundity. For example, Alaskan hares and arctic hares are subjected to prolonged periods of resource scarcity during the winter and have only one litter per year. Black-tailed jackrabbits and antelope jackrabbits live in desert environments and produce several litters a year; however, the litters of these two species are relatively small, containing only 1 to 3 young.

Hares are born fully furred, with open eyes and are able to run a few hours after birth. Rabbits are born with no hair and closed eyes but often have full pelage and open eyes within a couple of days after birth. Sexual maturity and weaning can occur at a young age for both groups but varies according to species. Generally, sexual maturation can occur from 3 to 9 months after birth in rabbits and 1 to 2 years after birth for hares. Females are larger than males in most species, which is unusual in mammals, and are able to reproduce before males. Weaning age is also species specific, but females generally nurse young for at least 3 to 4 weeks, beginning the weaning process about 10 days after parturition.

Key Reproductive Features: iteroparous ; seasonal breeding ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; induced ovulation ; fertilization ; viviparous ; post-partum estrous

Leporids employ a reproductive strategy known as "absentee parentism". In hares, precocial leverets are born in forms, small depression in the ground or surrounding vegetation, while altricial rabbit kittens are born in well-formed, fur-lined nests, constructed in underground chambers or in dense vegetation. Maternal care in leporids is limited to one visit every twenty four hours, usually lasting no more than 5 minutes. Mothers nurse their young during this brief period, which usually occurs during the evening. In species that create subterranean nests for their young, the entrances to these chambers are re-covered after each visit. In form nesting hares, each leveret disperses about 3 days after birth to find their own hiding spot, but rejoin their litter-mates everyday around sunset for their daily nursing bout. Absentee parentism is thought to have evolved as a predator defense mechanism. Leporid milk is extremely rich in fat and protein and is rapidly pumped into offspring during nursing bouts. Paternal care is limited to protecting offspring from rival females.

Prior to the birth of the kittens, rabbit mothers prepare a fir-lined nest for her young. Some species create an underground nest that is either part of a communal den or a remote “brooding tube” dug by the mother for the specific purpose of raising her young. Other species give birth in forms, which consist of small surface depressions filled with chewed-up twigs and leaves, or small depressions among the shrubs. Hares give birth above ground in a nest heap or on a patch of exposed soil.

Hares are precocially born while rabbits are altricially born. Sexual maturity and weaning can occur at a young age for both groups but varies according to species. Weaning generally begins about 10 days after birth and can last anywhere from 17 to 23 days depending on the species. Sexual maturation can occur from 3 to 9 months after birth in rabbits and 1 to 2 years after birth for hares. In social leporids, a mother's position in the hierarchy can affect the social status of their young.

Parental Investment: altricial ; precocial ; male parental care ; female parental care ; pre-hatching/birth (Provisioning: Female); pre-weaning/fledging (Provisioning: Female); pre-independence (Provisioning: Female, Protecting: Male); maternal position in the dominance hierarchy affects status of young

Barcode of Life Data Systems (BOLD) Stats
Specimen Records:496
Specimens with Sequences:405
Specimens with Barcodes:396
Species:27
Species With Barcodes:27
Public Records:145
Public Species:15
Public BINs:21

Thirteen species within Leporidae are considered threatened or near-threatened by the International Union for the Conservation of Nature (IUCN), 7 of which are either endangered or critically endangered. Of the 62 species listed by the IUCN, those threatened with extinction are often the most primitive. As leporid habitat is being destroyed to create room for crops, irrigation, and ranch lands, many species of rabbits and hares are forced to persist on remnant habitat islands that result in significantly decreased genetic diversity and ultimately, genetic inbreeding. Many native species are also vulnerable to increased competition for resources with invasive rabbits, the introduction of new pathogens, and the introduction of new predators. While habitat destruction poses the biggest threat to many native leporids, they are also vulnerable to competition with livestock for food resources, over hunting, and poisoning by farmers. Suggested conservation measures include the eradication of exotic predators, reducing habitat destruction and fragmentation, creating strict hunting regulations and enforcing those already in place, the establishment of habitat reserves, and increasing public awareness about the importance of leporid conservation efforts.