- Mary K. Hanson
- Posted On
Tuleyome Tales: Jackrabbits – more than meets the eye … or the ear
NORTHERN CALIFORNIA – We see them everywhere it seems, those agouti-furred critters with the huge ears we commonly refer to as jackrabbits.
But did you know that jackrabbits aren’t “rabbits” at all? They’re hares.
Hares differ from rabbits in size (hares are larger, have longer ears and bigger hind feet), speed (they’re faster than rabbits), and coloring (their fur is peppered with black markings).
Rabbits often live in underground burrows called “warrens,” but hares don’t. They prefer to spend their time in ruts or hollows on the ground’s surface or under the cover of grasses and shrubs.
And whereas baby rabbits (commonly called bunnies) are born underground, furless and blind, baby hares (called leverets) are born above ground and are fully furred with their eyes open so they can leave the nest and forage on their own very quickly after birth.
In fact, they’re so self-sufficient that the mother jackrabbit doesn’t protect or even stay with her well-camouflaged offspring during those times when the leverets aren’t nursing.
Female jackrabbits (which are generally larger than their male counterparts) aren’t too keen on preparing extensive nests for their babies either. They dig or commandeer shallow depressions in the ground, called “forms,” and drop the leverets in them. Sometimes the mother may line the form with fur, but more often than not, they’re left barren.
Jackrabbits can breed several times a year, and each litter can have up to 6 or 8 young in it. In this region, breeding times are usually in late winter or late summer, so that the offspring are born when young plants are most prevalent (in the spring and fall). An adult jackrabbit can weigh up to 9 pounds and grow to be about 2 feet long.
Big eaters (a little more than a dozen jackrabbits can eat as much in a day as a full grown cow!), the jackrabbit’s diet consist of a variety of grasses, coarse leaves, twigs, berries and other plant material. And, yes, they also eat their own feces, but only the “first pooped” version.
When the jackrabbit evacuates for the first time after a meal, the extruded pellets are green and filled precious moisture and vitamins (produced when the food passes through the intestinal tract). The jackrabbit immediately eats these pellets to gain the optimal fluid and nutrition from their meal.
When they expel the pellets for a second time, the pellets are brown – which is the form in which we usually see them – and, being of no further use to the jackrabbit, they are promptly ignored.
The jackrabbit’s most distinguishing feature is, of course, its set of large ears.
The ears not only allow the jackrabbits to hear exceptionally well, they also act as a kind of shock absorber when the jackrabbit runs. Jackrabbits can hit speeds up to 45 miles per hour, and the ears help to dispel some of the inertia that builds up in it head and body (allowing the jackrabbit to focus more clearly with its eyes as it runs).
The ears are also used to heat and cool the jackrabbit through a process called “thermoregulation.”
Blood vessels in the ears expand or contract to help the jackrabbit regulate its body temperature. The system works so well, in fact, that studies were actually done through the University of Arizona to replicate the process in building construction, utilizing a series of liquid-filled bladders in the walls that could expand or contract to help moderate the inside temperature of the building!
In the wild, most jackrabbits live a short life (1 to 5 years), and populations are usually well-controlled by predators that use the hares as the mainstay of their diet.
Commonly, jackrabbits constitute important prey species for hawks, owls, eagles, coyote, foxes and other animals.
It’s not uncommon to see the jackrabbits dashing across the landscape in a zig-zag pattern, and leaping occasionally (up to 10 feet) to confuse and avoid predators.
So, there you have it: Jackrabbits – more than meets the eye… or the ear.
Tuleyome Tales is a monthly publication of Tuleyome, a nonprofit conservation organization based in Woodland and Napa, Calif. For more information about Tuleyome go to www.tuleyome.org . Mary K. Hanson is an amateur naturalist and photographer and author of The Chubby Woman’s Walkabout blog.