DIPSOSAURUS DORSALIS

Special thanks to Bob Blome

General information
The Desert Iguana ( Dipsosaurus dorsalis), dipso for short, occurs in the desert / semi- deserts of Southern California, Nevada, western Arizona and northern, Mexico. The common Desert Iguana ( Dipsosaurus dorsalis) habitats the Mojave Desert of central California, through Nevada and the southwest part of Utah all the way to western Arizona. More south, west Sonora, into Mexico, northwest Sinaloa, we find Dipsosaurus d. sonoriensis. On the island Santa Catalina in the Gulf of Mexico we find Dipsosaurus d. cataliniensis. And the Dipsosaurus d. lucasensis (formerly known as Dipsosaurus d. carmensis) habitats the islands Isla del Carmen, Coronado’s, Montserrat, San Jose and Cerralvo and is also found in the south end of Baja California and western Mexico.

Habitat
he area Dipsos occur is described as deserts/semi-desert with big variations in temperature ranges between night and day. Their habitat is very dry, and they feel typically at home in the sandy desert and flats. They are found in association with creosote bushes, on rocks and even basking on roads. Dipsos are really territorial, especially in the breeding season when males will fight for a female. They often live in small groups with one male and several females. From November to March the will go into a winter resting period. Dipsos are diurnal lizards, very active during the day and bask a lot in front of their burrow, but they will retreat into their hides when the sense danger or when it gets to hot. But Dipsos like it hot and can be found basking when other lizards already retreat to their hides because of the heat. The digestion of a Dipsos only starts at 28 degrees Celsius.

Description
This slender lizard has a small round head with big ear openings and sturdy legs. The tail is round and long, the dipso can grow up to 40-45 cm and more than half of the length is tail. If the tail is lost it can regenerate, but will never be as beautiful as it was before. The scales on the head and the back are relatively small, and the dorsal scales are keeled, and become slightly larger down the center of the back. This forms a well-defined crest that extends along the back and all the way down the length of the tail. The ground colour is cream white, with bands and stripes in various shades of brown / reddish and grey.

Cage
I always say the bigger the better! I keep my Dipsosaurus in a terrarium measuring 150cm x 70 cm x 70 cm with a back wall they can climb on. This cage is big enough for a trio of Dipsos if you keep more than 2 together make sure to check for signs of aggression or stress. I advise not to keep 2 males together they will fight with each other, but even females can be aggressive to each other. Make sure all animals have their own hide, and provide multiple basking areas, so they can avoid each other. To create different hides I used flagstones, I placed them in 3 layers from the ground up to create multiple hides even under the sand (they can dig themselves) make sure that all stones are safely secured so the stones can’t roll over and fall on your animal! The substrate I use is washed play sand. To finish the enclosure you can use different kind of rocks / wood and fake plants.

Lighting / heating
As Dipsos are real sun loving lizards there can’t be too much light in the cage. The lighting consists of a ReptileUV Mega-ray (100W) and a 60 W incandescent spot lamp. UVB lighting seems to be very important for the proper growth and behaviour of these lizards. Without it these animals cannot process calcium and will quickly become calcium deficient and parish. Besides these lizards can see more colours than humans, all the way into the UVB spectrum, this might play a role in finding food and courtship. The lamps are on for 12 hours a day (summer 14 hours, winter 8 hours). Dipsos get active when the air temperature is about 30°C – 32°C and start roaming around and looking for food. The temperature under the UVB-lamp is 55+°C and a few degrees cooler under the 60W spot lamp. Nightly temperature can be dropped to about 20°C.

Care
Mature and juvenile Dipsos are fed 6-7 times a week.The main part of their diet is vegetable matter and a small part insects, locust or wax moth larvae are favourite insects for these guys. A very important aspect of the diet is to vary the vegetable matter fed to your Dipso. Iguanas are mainly fed protein rich veggies with endive as the number one staple. The endive is mixed with rasped carrots, dandelion (flowers and leaves), cabbages and paksoi. The Dipsos also like birdseed, pollen granules and lentils. Food is powdered with a calcium and vitamin supplement. Once every 2 weeks the terrarium is misted. Normally a healthy Dipso will obtain the necessary water from his food and does not need a water bowl. When a female is gravid with eggs, I mist one end of the cage everyday. If you have a sick dipso or a dipso that’s recovering or dehydrated it is wise to have a small water bowl available in the cage at all times.

Breeding and incubation

After receiving my breeding stock the in 2007, and having a period of acclimatizing and a winter resting period, the following spring my male began doing push ups and began chasing the females. After a week I saw them mating, and on the 28 of April I found 5 little eggs buried in the sand. I put them in an incubator at 30-32 degrees and on the 7th of July (71 days) the first dipso appeared. All 5 eggs hatched in a period of 3 days.

On the 5th of June the same female laid her second clutch of the year, 6 fertile eggs were found almost in the same place she laid them the first time. At this moment they are still in the incubator and probably will hatch the middle of August. (these all hatched) And the next year they bred again for me.

Raising the juveniles
After the eggs hatched I placed the little dipsos in a small terrarium with a UVB bulb and with newspaper as substrate. After 2 weeks I changed the substrate to sand. The little dipso eat small crickets and greens cut in very small pieces. I add calcium every other feeding. Hope to tell you some more about raising them in the next few months.

Conclusion
Dipsosaurus dorsalis is a very active lizard which can be maintained in captivity if optimal conditions are created for housing, feeding, health, acclimatization and heat/light. For advanced reptile hobbyists this species gives a nice challenge in caring and breeding them. Off course we want to see a healthy population in captivity this is why we think the Studbook is a great idea for this species.

ESF Studbook

Recently a studbook is founded for this species. After Michel and Kamiel imported 28 animals in 2007 (almost all are included in the studbook) there was a good amount of founder animals to start with. The studbook is to create / maintain a healthy captive population, and in case of threatened species to help to maintain the species and breed them for eventual re-introduction programs.


Literature

Desert Lizards Captive Husbandry and Propagation (door Randall L. Gray) Krieger Publishing Company Malabar Florida ( ISBN 1-57524-160-9)

Sauromalus & Dipsosaurus Verzamelnummer (SDGL / verschillende auteurs)

Reptiles Magazine, October 2004 The Desert Iguana (auteur Craig Ivanyi)