Lepus insularis
black jackrabbit

Lepus insularis is endemic to Espiritu Santo Island in the Gulf of California, Mexico, from sea level to 300 meters elevation. It has also been introduced to nearby Pichilinque Island (Thomas and Best, 1994).

This species, also known as black jackrabbits, is found all over Espiritu Santo Island but is most abundant in the valleys and adjoining lower slopes of the hills. Espiritu Santo Island is a waterless volcanic island characterized by rocky hills and low mountains. Black jackrabbits favor places scattered with arid tropical shrubs, cacti, and other plants since the upper slopes are rocky and barren (Thomas and Best, 1994).

Black jackrabbits have a characteristic glossy black head, usually with a few white hairs on the middle of the crown and grayish hairs near the ears and eyes. The rest of the upper pelage, including the top of the tail, is glossy black with fine grizzling of dark cinnamon. The cinnamon color predominates ventrally. A black line extends along the inner sides of the hind feet from the toes to slightly above the heel. The soles of the feet are heavily padded. Average body size is 574 mm and average tail length is 96 mm. Like other hares, females are usually larger than males (Dixon et al., 1983).

Black jackrabbits are solitary animals. Rather than digging and occupying burrows, they rest and take shelter in shallow depressions made in soil or vegetation. There, black jackrabbits resemble a short, charred stump among the gray-green vegetation and bare slopes and are extraordinarily conspicuous, even when motionless. Black jackrabbits are mainly nocturnal. During the day, they spend most of their time in the shade under bushes. During the most active part of the mating season, the males lose their customary caution and are abroad fighting with other males and pursuing females. Fighting consists of boxing with the fore feet or kicking with the hind feet. When mating, females may be quite seriously mauled by their overenergetic consorts who bite and kick them (Nowak, 1983).

Lepus insularis is an herbivore. Grasses are the preferred food choice of black jackrabbits, but these animals have also been known to consume tree bark when other food supplies are not readily available. Since Espiritu Santo Island is a virtually waterless island, all of the required water is obtained through ingested vegetation (Nowak, 1983).

During the dry season when green vegetation is scarce, hares will gnaw on bark. As a result, orchards and plantations suffer at this time because the hares girdle young stems and cause plants to die (Bourne, 1997).

According to local fisherman, humans from nearby Pichilinque Island hunt black jackrabbits for food. Although its fur is not particularly valuable nor durable, it has been used to manufacture felt (Nowak, 1983).

The only predatory mammal on Espiritu Santo Island is Bassariscus astutus, which probably never hunts even young black jackrabbits. A few American kestrels and caracaras are the only birds of prey known on the island, thus the natural enemies of black jackrabbits are few. Since Espiritu Santo Island may never be inhabited by humans, black jackrabbits seem in no immediate danger and the population is stable. However, it may be wise to consider establishing another population on some nearby island (Thomas and Best, 1994).

Populations of Lepus californicus in what appears to be the same climate, vegetation, and other physical surroundings on the mainland exhibit no sign of melanism. The isolation of L. insularis on Espiritu Santo Island, combined with the virtual absence of predatory birds and mammals, has apparently removed selection pressure favoring cryptic coloration.

Lepus insularis is a close relative of L. californicus of the nearby peninsula of Baja California. The species-level status of L. insularis has been questioned. However, in a multivariate comparison, there was a distinct separation based upon cranial characters.

The genus name Lepus is derived from the Latin lepus, meaning hare. The specific epithet insularis comes from the Latin word insula indicating the island range. Additional names include black hare and Espiritu Santo jackrabbit (Thomas and Best, 1994).