As desolate as the desert might appear, Joshua Tree is quite alive. True, the desert tortoise, which spends an estimate 95 percent of its life underground, might not be readily visible. But birds always seem to be flitting about, as are lizards.

But the tortoise, which are thought to have crept across the earth for 15 or 20 million years, might be one of the most intriguing creatures of this landscape, largely because it has seen better days and currently is precariously perched between extinction and another long run.

Today listed as “threatened” under the Endangered Species Act, the desert tortoise leads a tough life. Its eggs and young are preyed upon by ravens, badgers and other predators. Plus, believe it or not, it can be afflicted with a respiratory illness borne into the wild by pet tortoises set loose.

Fortunately, for their long-run prospects, desert tortoises can reproduce any time of year. But the average clutch size is only five, so females are not particularly prodigious. As with the eggs of sea turtles, the temperature of the earth surrounding the nest determines the sex of the hatchlings.

As for their burrows, don’t think they’re particularly cramped, for they can run 30 feet (9 m) in length. As for the arid landscape in which they live, desert tortoises have been known to dig depressions to catch rainwater.

While tortoises might get top billing among Joshua Tree’s wild kingdom, they share it with many other creatures. Many bird species call the park home, including the loggerhead shrike, which will impale its prey on sharp-pointed leaves. Wheeling in the skies overhead you might see red-tailed hawks or, if you’re sharp-eyed, American kestrels.

Skittering across the desert floor are not only Zebratail lizards, iguanas, rattlesnakes, and Kangaroo rats, but kit fox, desert woodrats, Chuckwallas, and black-tailed jackrabbits, as well as Greater roadrunners. Up higher in elevation you might encounter bighorn sheep.

Black-tailed jackrabbit, Joshua Tree National Park / NPS - Jane Gamble