The white flanks are the quickest clue
The white-sided jackrabbit is a large hare with long ears, powerful hind legs, and unusually pale sides. A dark stripe runs along the back, creating a sharp boundary with the whitish flanks. When the animal runs, that contrast can be easier to notice than any single measurement.
Black-tailed jackrabbits share parts of its range and are much more familiar to many observers. They usually look browner and show stronger black on the tail and ear tips. Lighting can blur those differences at night, so photographs showing the back, sides, and tail are far more useful than a distant silhouette.
Despite its name, a jackrabbit isn’t a rabbit in the narrow biological sense. It’s a hare. Young are born furred, with open eyes, and can move soon after birth. That early independence suits an animal raising young in exposed grassland.
A narrow United States foothold
Most white-sided jackrabbits live in Mexico. Their United States range is limited to southwestern New Mexico, close to the border. They favor broad, open grasslands at moderate to high elevations, where scattered shrubs don’t close the view.
This isn’t simply a desert animal. Healthy grass structure matters. Too much woody growth can break up open habitat, while severe grazing can reduce food and cover. Fire, rainfall, livestock use, and shrub removal can therefore change the same grassland in very different ways.
Confirmed records are scarce and uneven through the year. That doesn’t establish that the hares use an area only in recorded months. Night activity, private land, difficult access, and low survey effort all shape what reaches a database.
What happens after sunset
White-sided jackrabbits rest in shallow forms during the day, relying on stillness and their coat for concealment. They become more active toward evening and at night. Long ears help detect danger and also release heat, while long legs provide sudden speed across open ground.
Their food is plant material, not the predators listed among their interactions. Grasses dominate where they are available, and other low plants can supplement the diet. The current quick-facts diet label and item list conflict with that well-established herbivorous biology, so those automated fields need correction before they’re treated as descriptive evidence.
Feeding in open country demands constant attention. A hare may pause upright, rotate its ears, and then resume clipping plants. When danger gets close, it accelerates in long bounds rather than retreating to a burrow.
Courtship pairs on the grassland
This species is notable for pair behavior. A male and female may remain near each other, especially during the breeding period, and nighttime chases can include striking white flashes from both animals. Those displays make the pale sides more than camouflage or a field mark; they may also help the hares follow one another in dim light.
Females can produce more than one litter when conditions allow. Each young hare is left concealed separately, reducing the chance that a predator finds the entire litter at once. The mother returns to nurse, but she doesn’t keep the young together in a nest.
Rainfall influences grass growth, which in turn affects the energy available for breeding and survival. A dry year can matter long after the rain fails because food, cover, and reproduction are connected.
Why this hare is vulnerable
The IUCN lists the white-sided jackrabbit as Vulnerable. Its small United States range makes local habitat changes especially important at the northern edge. Shrub invasion, grassland conversion, roads, fencing, and poorly timed land use can divide or degrade the open country it needs.
This hare also illustrates why occurrence records need careful language. Nine recent New Mexico records confirm persistence in a limited area, but they can’t tell us the population size or trend by themselves. Repeated surveys using consistent methods are needed for that.
Protecting the species means keeping large grassland blocks connected across the international border. It also means maintaining the grass itself rather than treating every treeless acre as equal habitat. The white flanks are memorable, but the deeper story is a specialized hare holding on in one of the country’s smallest mammal ranges.
