Blog


Sonoran Desert Tortoises


Some readers have asked me about Tonka, my desert tortoise, so I thought I'd write a little bit about the Sonoran Desert tortoise.

There are thirty-nine species of tortoises worldwide and they differ from turtles in that they are entirely land-based, rather than living in and near the water. In fact, they cannot swim and will drown in water over their head. Four species of tortoises have been living in North America for thirty million years, essentially unchanged.

Tonka is a Sonoran Desert tortoise (Gopherus agassizii). These tortoises live in the Sonoran Desert, in Arizona and Sonora, Mexico, where they are called la tortuga de tierra (land turtle). They prefer rocky slopes, washes and bajadas (alluvial fans at the base of mountains). The other Southwestern desert tortoise is called the Mohave Desert tortoise and occurs in the flat desert valleys and basins of southeastern California, southwestern Utah and southern Nevada.

The desert tortoise has a high domed shell (carapace) composed of individual scutes, which are usually light brown in adults and dark tan in younger individuals. The tortoise's hind limbs differ markedly from the forelimbs. Whereas the hind limbs are elephantine, the forelimbs are flattened with well-developed muscles and are covered in thick protective scales. The forelimbs are used for digging burrows. The females use their hind limbs to dig their nests.

Both sexes have a gular horn under their chin—the horn is an extension from the plastron (lower shell). The horn is longer in males, and is used in fighting in an attempt to flip the other male over onto their back. The tortoise also has a short stubby tail, longer in males than females.

Tortoises can live up to 100 years. Unlike some of the giant tortoises, such as the Galapagos tortoise, the desert tortoise will only reach a length of 8 to 15 inches and weigh 8 to 15 pounds. They are herbivorous and their primary food is native and introduced grasses. They also eat the leaves, stems and flowers of many desert plants, including prickly pear cactus pads and fruit.

They are well adapted to living in the desert environment, surviving temperatures up to 140° F. by using burrows, rock outcrops and the shade of bushes to help regulate their internal temperature. They spend up to 95% of their life in these small dens. They hibernate in burrows during the colder winter months, and are active during the day and evening from spring through autumn. During the hottest part of the summer day, though, they will remain in their burrows to conserve moisture and energy.

Tortoises obtain most of their water from the plants they eat. Adults can survive a year or more without drinking any water. During periods of drought, they retain water in their bladders, able to reabsorb it if needed. As a defense mechanism if molested, tortoises will empty their bladder if they feel threatened, so please do not pick up tortoises in the wild. You may very well be the cause of its subsequent death if it cannot quickly replace the lost moisture.

Tortoises are primarily solitary creatures, though they may share burrows. Males seek out females during the mating season, but will fight other males they come across. After breeding, females lay 4 to 8 eggs in a shallow nest dug into the soil usually near the burrow. Gestation is 90-120 days. Data from experiments using controlled incubation temperatures show that cooler temperatures, 79-87 degrees F. produce all males; at 88-91 degrees F. all females.

Hatchling tortoises are small (about 1½ to 2 inches in length), and have thin, delicate shells. They are prey to many animals, including coyotes, foxes, bobcats, ravens, roadrunners and Gila monsters. Less than 2% survive to adulthood. Tortoises grow at varying rates depending upon forage availability; sexual maturity is a function of size rather than age, though sexual maturity usually occurs at 15-20 years of age. Tortoises can make a variety of sounds from hisses, pops and poink sounds, perhaps as fear and distress calls. Males grunt when mating. Surprisingly, tortoises can run fast for short distances when trying to escape other males.

The population of the Sonoran Desert tortoise has been steadily dwindling since the 1950s, when the human population in the Southwest began to grow so rapidly. Habitat destruction due to urban area expansion, home construction, canals, roads and off-highway vehicles, and competition from grazing cattle (they both eat the same grasses) are the main cause of the population decrease, but people capturing wild tortoises as pets also contribute to their decline.

Most captive tortoises don't live long, due to improper care (do not feed them lettuce, please, feed them grass). It is now illegal to remove a tortoise from the wild; it is also illegal to release a captive tortoise into the wild as it may spread diseases (mainly an upper respiratory tract disease) throughout the wild populations. Captive-bred tortoise can be adopted through several regulated sources, though.

That is how I came to have Tonka. We've been together since the early 1980s. My xeriscape backyard is designed to provide suitable desert tortoise habitat and Tonka thrives in it. Tonka seeks me out when I'm gardening, and I oblige with soothing head scritches and the occasional treat of a strawberry or grape.

Lazy Enchiladas Recipe

A reader (thanks, Angie) suggested I include some of Rima's favorite recipes on this website, so here is the recipe for Lazy Enchiladas, a family favorite, as mentioned in Chapter 5 of Condor Moon. The amounts of any of the ingredients can be modified to suit your family's tastes, but this is a good place to start. If you'll remember, Rima reduced the amount of cheese, added red bell peppers and replaced the ground beef with chicken to make it more heart healthy for Hix.

Larkin's Lazy Enchiladas: Mexican comfort casserole!

Ingredients

2 lbs ground beef (or chicken or turkey)

1 cup finely diced yellow or sweet onion

2 cloves minced garlic (or 1 tsp garlic powder)

1 tsp Mexican oregano

1/2 tsp black pepper

1/2 tsp cumin

1/4 tsp cayenne pepper (or more if you like it hot)

1 7oz can diced green chiles

30 yellow corn tortillas, torn into 5-6 pieces each

1 27oz can red enchilada sauce

1 7oz can El Pato Mexican-style tomato sauce (or any non-chunky salsa like Pace)

3-4 cups shredded cheddar cheese

Directions

In a very large pan/skillet: Brown the ground meat and then drain the grease. Add diced onions, garlic, seasonings and green chiles. Mix in 15-20 torn up corn tortillas, and add 2 cups of the shredded cheese. Add enchilada sauce and Mexican salsa and stir together.

Spoon mixture into 13x9 pan (greased or lined with foil helps clean-up). Tear up remaining corn tortillas to cover the top of the mixture (you can also tear up more for the bottom of pan before adding mixture if desired, especially if it seems soupy). Cover the top with several handfuls of cheddar cheese; don’t skimp if you want a crispy yet chewy layer.

Bake at 350° for at least 45 minutes or until top layer of cheese is crispy but not burned (may need to increase oven temp at end to crisp up).

Let stand for 10 minutes to set up, then serve.

Optional—Garnish with diced green scallions, fresh diced tomatoes, sliced black olives and a dollop of sour cream. Serve with warm, buttered flour tortillas and a green salad. It freezes well and is great warmed up the next day!


Paperback Version is Available

I finally finished the paperback version of Condor Moon, and it is available on Amazon.com. Barnes & Noble has also listed the ebook version for the Nook, and is it is available from several ebook subscription services such as Oyster and Scribd. Follow me on Goodreads as I plan to announce a book giveaway during the first full moon in July. Maybe it will be a Condor Moon?

Condor Moon is now available!

Condor Moon is finally available for purchase! I self-published my first novel. It went on sale at Amazon.com for  Kindles, and on Smashwords as an epub or pdf on May 16, 2014. And on May 19, it was listed at Apple's iBookstore as an iTunes download. It will soon be available for purchase at Barnes & Noble for the Nook, and for other ereaders at online book retailers such as Kobo, Oyster, Scribd, Page & Foundry, Baker & Taylor Blio, Flipkart (India) and 'txtr (Germany). It is currently offered to libraries through Library Direct, Baker & Taylor's Axis360 and OverDrive. It will also be available soon at Amazon.com as a paperback book. I'll post here when Condor Moon is available at these other retailers. I'm excited, if you can't tell. 

First Post

I'm not much of a blogger, but I will try to add book news, and personal events and thoughts when I can.

I am excited to announce that my first novel, Condor Moon, will soon be available as an ebook at online retailers everywhere and from Smashwords. In addition, the paperback version will be available on Amazon.com. It's really happening! I'm going to be a published author of fiction. 



tanna@tannathornburg.com © Tanna Thornburg 2014