Kangaroo Rat

NPS photo

 

NPS image/Alexander, Byron

Who are They?

Despite its name and mouse-like appearance, the Kangaroo rat is neither a rat or a mouse. The Kangaroo rat is a member of the heteromyidae family, with its closest relative being the pocket gopher.

Kangaroo rats have long tails and larger hind feet with only four toes. Their eyes are very large, while their ears are incredibly small. Kangaroo Rats are small, weighing up to 4.5 ounces, which is about the weight of granola bar. Their fur is a yellowish-brown with a white belly, while the tail has a noticeable white tip.

Kangaroo rat tend to live in the desert flatlands, creosote flats, and the sandy soils of the desert washes. The rats burrow into the soil to better survive the sometimes harsh desert environment.

Kangaroo rats are mostly seed eaters, eating mostly mesquite beans and grass seeds. Occasionally the Kangaroo rat can be seen eating small insects. Kangaroo rats will forage and collect seeds at night, storing seeds and beans in their cheek pouches. Extra seeds are stored in their burrows where the seeds can absorb up to 30 percent more moisture.

 

Kangaroo rats live and hide in burrows.

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How many different species are there?

There are a handful of kangaroo rat species in the Sonoran Desert. The most commonly encountered one at Organ Pipe Cactus is Merriam’s kangaroo rat. You may notice some smaller kangaroo-rat-like rodents called pocket mice. It’s hard to tell exactly who you’re looking at if you only get a brief glance, but pocket mice are generally the smallest, at about the size of a Brussels sprout. Kangaroo rats are about palm-sized. Packrats, who are not closely related, but found in the same area are fairly large, at about the size of a large orange or small grapefruit.

The different species of kangaroo rats and pocket mice look fairly similar, with silky gray-brown to yellow-brown fur, lighter colored bellies, and long tails with a tuft of hair at the end.

 

Kangaroo rats have powerful hind legs and a long tail for balance.

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Evolved for the Desert

Kangaroo rats are masters of desert survival. Their bodies adapted to reduce the amount of water needed and the amount of water that is lost.

Although a kangaroo rat's diet is mostly consists of dry seeds, it has almost no need for liquid water. Instead, they survive almost entirely by transforming fats from the seed into water through digestion. Kangaroo rats can extract a half gram of water out of every gram of seeds consumed — thats about one drop of water for every two seeds! Their kidneys concentrate their urine to an almost crystal-like consistency, so that very little water is lost through waste.

Kangaroo rats don't even need water to bathe. Instead of cleaning themselves by licking their fur, they will take a dust bath by rolling around in the sand.

 

A bobcat with prey. Notice that the prey is a white-throated woodrat.

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Agile Rodents of the Desert

Kangaroo rats have adaptations that allow them to detect and escape predators easily.

A kangaroo rat's massive hind legs allow them to leap forward nine feet in one bound, helping them escape fast and sneaky animals. The kangaroo rat's long, rudder-like tail help it maneuver quickly through the brush. When they jump, they can use their tail to change their direction mid-air! This is super helpful when avoiding the lightning-quick strike of snakes.

The kangaroo rat has keen ears to detect the approach of snakes and other predators.Their large, sensitive eyes also allow them to see through dark nights. In the event that these small mammals are snatched up by a predator, there is a decent chance that they have already passed their genes onto the next generation. Their tenacity and quick reproduction help ensure that there are plenty of these little critters around, even if some unlucky ones fall prey.

Cautiously, these animals proceed through the desert, using adaptations to outmaneuver predators and make due with little resources. If you walk along a trail or road at night, you are likely to see some of these rodents scurry or bound across your path.