Black-tailed Jack Rabbit (Lepus californicus)
Main sources: Hoffmeister, D. F., 1986, Mammals of Arizona, pp. 144-5, Tucson, University of Arizona Press; Burt, W. & R. Grossenheider, eds., 1976, A Field Guide to the Mammals, , pp. 206-7, Peterson Field Guides: Houghton Mifflin; Cockrum, E.L., 1960, The Recent Mammals of Arizona: Their Taxonomy and Distribution, Tucson: University of Arizona Press; Merlin, Pinau & Peter Siminski, "Rabbits and Hares", in Steven Phillips and Patricia Comus, eds., 2000, A Natural History of the Sonoran Desert, pp. 493-5, Arizona-Sonora Desert Museum Press, Tucson
The
Blacktail Jackrabbit and the Antelope Jackrabbit (Lepus alleni)
are similar in shape, and both appear in our area (though the Blacktail is much
more widely distributed in Arizona; the Antelope's distribution barely reaches
our area along the San Pedro River -- see Cockrum, p. 68). The main feature distinguishing
the two is the Antelope's huge ears, without black on them.
(It also typically has pale, whitish sides and hips.) The
Blacktail, in contrast, has ears with black tips (especially conspicuous
on the dorsal sides), and its ears are not quite so outsized. Both species
have black tail top and adjacent rump. In the photograph above left, identification
is ambiguous since the ears are impressively large, the ear tips are not obviously
black, but the sides are not pale. We are inclined to think however that all of
the Jackrabbits we have seen here are the Black-tailed.
In
the image at right, this is clearly a Black-tailed Jackrabbit. Note how
the large eyes are placed high and towards the back of its head -- this allows
it to see at very wide angles when watching for predators. (Click
on the image for a close-up.)
In contrast to the Desert Cottontail Rabbit, our Jackrabbits tend to occupy drier, more open parts of the desert than does the Cottontail, where they can spot predators from a distance. Like the Cottontail, they are mainly nocturnal, becoming active as the sun goes down and then (unlike the Cottontail) foraging as far as several miles a night in search of the grasses, forbs, shrubs, and cacti which they eat. If they see a predator they may freeze until approach is close, when they leap away in 15 foot bounds, running quite fast, more than 30 mph. They also have considerable stamina for the chase.
Here,
at left, is an image of a Blacktail Jackrabbit (despite the limited anatomy
visible, it's identifiable by its black ear tips), taken in the afternoon August
sunlight of 2003. Note how the sunlight streams through the body of the left ear,
revealing its translucent thinness (these large, thin ears are viewed as an adaptation
for veinous cooling in the summer heat of the desert). You can also see that,
despite the rabbit's posture nearly 180 degrees away from the photographer, the
orbit of the left eye is clearly visible. It is watching us! (Click
on the image for a close-up view.)
The Antelope Jackrabbit is quite large (from 6-13 lbs., it is one of the largest Hares in North America), while the Blacktail is somewhat smaller (3-8 lbs.). Unlike the Cottontails (who breed mainly in spring and summer), Jackrabbits breed throughout the year, following dramatic, athletic courtships, and their young are born furry, with open eyes, and ready to move shortly after birth (though the young remain with their mothers longer than do the Cottontails -- for several months). When adult, Jackrabbits are also highly social, gathering on moonlit nights for conclaves reaching a dozen or more (Pinau & Siminski, p. 495). More solitary by day, when they remain still in the bushes they are quite well camouflaged, as you could see on the banner photo at the top of this page; below, a closeup of this same very wide-awake beast (seen at Collardlizard Hill, lower Hot Springs Canyon terrace, September 10, 2004):
Most typically, we encounter them the lower reaches of our largest washes, either in the early morning or late evening, as below, in March 2005:
