Angel Island chuckwalla

- Sauromalus hispidus

The Angel Island chuckwalla (Sauromalus hispidus) it is found in the northwestern islands of the Gulf of California (Mexico): Guardian angel, Granite, Mejia, Pond, Saint Lawrence North, South San Lorenzo and smaller islets in the Bay of Los Angeles (Horse's head, Window, Louse, Arrow, Mitlán and Coronado). These islands make the west cool and mild in winter and hot in summer..

The Angel Island chuckwalla it is the second largest species of the genus Sauromalus (chuckwallas), reaching 44 cm of body length and 64 full length cm, and weighing up to 1,4 kg. It is considered a gigantic species, as it is two to three times the size of their counterparts on the continent. Its body color is a dark brown color with black transverse bands that fade into a solid darker brown to black color as the animal ages..

The vegetation is dominated by xerophytic plants. Characteristic are the large cardon cactus (Pachycereus pringlei) and creosote bushes (Larrea tridentata).

The Angel Island chuckwalla it is present in all the smaller islands, but generally prefers the vicinity of rocky areas where animals find their hiding places.

But, due to the influence of the sea, humidity is generally higher than in mainland parts of the Sonoran Desert and rises sharply at night, with occasional early morning mists. Extreme temperatures are a minimum of 8 °C and a maximum of 43 C.

When two adults meet, they occasionally flatten on their sides and threaten each other with typical iguana “shoves” and head nods. But, the animals do not come any closer and move to another rock after a short time.

Also striking is the general absence of any flight reaction towards humans..

Once the morning mist has cleared (between the 8 and 10 in the morning), the Angel Island chuckwalla appears on rocks to warm up in the sun. After the first sunbaths in the morning, many of the observed animals migrate to the canyon, where they feast on growing strawberries.

In the afternoon there is a second phase of activity, in which many animals go back into the canyon and look for food there.

State of conservation ⓘ
in danger ⓘ (UICN)ⓘ

The Angel Island chuckwalla (Sauromalus hispidus) has recently been assessed by the IUCN Red List of Threatened Species in 2018. Sauromalus hispidus is listed as In danger under criterion B1b

The islands of the distribution area of ​​the Angel Island chuckwalla have been protected by the Mexican government through the decree of the 2 in August of 1978 as "Reserve and Refuge for Migratory Birds and Wild Fauna". It also, Mexican legislation prohibits in principle the capture of reptiles for commercial purposes from 1952.

The Environmental Protection Law of 1988 establishes in principle that the taking of reptiles from the wild for commercial purposes is permitted under certain conditions, but until 1993 at least, there were no application guidelines for it, and the Mexican government had not issued a single permit for Baja California or the islands of the Gulf of California.

In the Decade of 1970, the giant chuckwallas (mainly Sauromalus varius, but also Sauromalus hispidus) were captured for the pet trade. MELLINK (1993) points out that illegal collection activities continue and that this also affects the Angel Island chuckwalla. While the Sauromalus varius is included in Appendix I of the WA, There is no international protection status for the Angel Island chuckwalla (Sauromalus hispidus).

It follows that at least most of the giant chuckwallas circulating in the terrarium trade must be illegally harvested animals.; this applies to all animals originating from Baja California or from the islands of the Gulf of California. The Angel Island chuckwalla (Sauromalus hispidus) it is rare in the international pet trade, but regularly shows up there at fairly high prices as claimed pups (in july 2001 the species was offered by two dealers in Germany). In U.S.A. the Angel Island chuckwalla (Sauromalus hispidus) is maintained and reproduced by at least three private owners.

The data indicated here are those corresponding to HEIKO WERNING, a breeder of "Angel Island chuckwalla"

All the animals were always kept together in the same terrarium.. Initially I housed them in a terrarium of 150 x 200 x 200 cm. (wedged in a corner of the flat with diagonal walls, hence it only has average measurements), which was lit by an HQI burner of 150 W y luz natural (a "terrarium wall" was an exterior window).

The "terrarium wall" was an exterior window). a focus of 100 W, shining from a distance of about 30 cm on a platform of artificial rock, served as a hot island. Another local heat source was the HQI lamp ballast, which was mounted on the ground and covered by a metal plate. In both heat islands the temperatures were 40-50 C, The ambient temperature in the terrarium varied between 25 and 35 C, depending on the measuring point. In summer, temperatures could rise above (up to about 40 °C ambient temperature), in autumn and spring they were below (up to about 20 °C ambient temperature). At night, values ​​dropped at room temperature (normally 18-22 C). The duration of artificial lighting was 14 constant daily hours outside the winter rest period; the total length of the day varied throughout the year depending on daylight hours in Berlin due to light from outside. In winter, artificial light sources were turned off for a period of 8 to 12 weeks, so that the values ​​dropped to room temperature throughout the day and only natural light from outside illuminated the terrarium.

The terrarium was furnished with artificial rock constructions made of Styrofoam, which were covered with wood glue and then sanded. The artificial rocks manufactured in this way turned out to be quite resistant., even to the mighty claws of the chuckwallas. Several vertical and horizontal "cracks" in the Styrofoam served as hiding places for the lizards, what they used at night, sometimes during the day when it was hot in summer and to hibernate in autumn and winter. The slits were designed in such a way as to provide a comfortable shelter for the animals., but at the same time they always offered contact surfaces from above and below. Sand available on the market was used as substrate., and the set-up was completed with a large climbing branch that almost filled the room and reached just below the HQI spotlight.

In 1999 I move house, and as the new terrarium originally intended for the chuckwallas could not be completed at the moment, they had to move to a much smaller enclosure. They are now kept in a terrarium of 150 x 70 x l00 cm, with whom he had already had a good experience in the maintenance and breeding of common chuckwallas (Sauromalus obesus BAIRD, 1859) (WERNING 1998) and that animals still inhabit today.

Two fluorescent lamps 60 W, a focus of 60 W shining on an artificial rock platform from a distance of 30 cm., and the UV lamp «Osram Ultra Vitalux" from 300 W, which is mounted on the lid and burns irregularly once or twice a day for 1-4 hours from a distance of about 60 cm., serve as lighting. This terrarium is also mainly equipped with artificial rocks (made of polystyrene and polyurethane foam, again painted with wood glue and then sanded). Borders and cork boards serve as additional structural and concealing elements. The temperature and lighting regime is similar to that described above, with the exception that there is hardly any natural light.

The tenarium is watered at irregular intervals at night.

Water is usually available in a small bowl. Animals have never been observed drinking.

According to the herbivorous way of life, I feed my chuckwallas almost exclusively with plant foods. They are fed an average of three to five times a day at will, that is to say, animals receive the amount of food they eat throughout the day. The main ingredient is lettuce, which has a very high calcium content compared to other leaf lettuce. From the beginning, constituted between 2/3 and 80% of the ration. If this lettuce is not available in season, a mixture of green lettuce, iceberg lettuce and other leaf lettuce (trade name "mixed lettuce") served as main food.

This basic diet is supplemented with other plant foods (mainly banana, Cucumber, tomato, chickweed, Apple, strawberries, grapes, carrots); occasionally I also offer food for animals (young mice, grasshopper, zophoba larvae). Juveniles still do not accept animal food; only at the age of 2-3 years showed for the first time a cautious interest. The Sauromalus hispidus adults from about five years of age, on the other hand, they pounce on all offered food with great avidity and clearly prefer it to any type of vegetable food.

Plant feeds were generally mixed with a mixture of vitamins and minerals. There was no exact dose, but they mixed 1-2 ml of the preparation with the green food in approximately three out of four meals as a well-tested empirical value from the care of the Dipsosaurus dorsalis and Common chuckwalla Sauromalus ater.

I feared giving the animals too many vitamins and reduced the addition to every one or two weeks, but I also offered them crushed egg shells and pieces of cuttlefish so that they could meet their calcium needs on their own.. After wintering 1999/2000, clear symptoms (hind leg lameness, slight deformation of the bones) showed that three of the four juveniles of 1997 suffered from a calcium deficiency. A diagnostic examination with rontographs confirmed the suspicion. Two animals died shortly after, one of them could be saved with the administration of vitamin D by the veterinarian. Hind leg injury healed almost completely, the animal returns to normal mobility and shows only slight changes in movement compared to other animals. Since then, the animal has been fed again with a mixture of vitamins and minerals, as described above.

In winter 1999/2000 the animals hibernated from early December to early February. From April 2000, the two adult males displayed completely different behavior. They threaten each other several times a day by flattening on the side and nodding their heads. They stood facing each other, leaning towards each other, so that the two animals together formed almost a circle. after a few nods, they started hitting each other with their tails. Either one of the males ran away, or a few flicks of the tail caused one of the animals to run towards the other and try to bite, what was partially successful. The second male then fled and was chased by the winner through the tenarium for some time., sometimes for several minutes, until finally he left her and the situation relaxed for a while.

In May, these fierce fights, which in two cases resulted in smaller but bloody bite wounds, could be seen almost every hour. But, while they fed, the two males continued to ignore each other and fed together without disturbing each other. If the superior male stood directly in front of the adult female during the chase, he left the adversary and impressed his partner by nodding his head. The 15.5.2001 mating was observed. It took place on the highest rock platform in the corner of the tenaria, illuminated by spotlight. The male had bitten the female's neck in typical iguana fashion and pushed her cloaca below that of his mate.. As I only arrived during copulation, I can't tell how long it lasted. Some 60 Seconds later, the male abandoned the female and a large drop of sperm from the female came out of his cloaca. No more matings could be observed, but the rivalry between the two males remained just as intense until June, and there were repeated clashes between the two until hibernation. In 2001, on the other hand, only very isolated fights without biting attacks were observed between the males.

After observed mating, the female showed a large appetite and quickly gained visibly in body size.

The eggs were visible under the skin when the animal was at rest.. About a week before egg laying, the female began to dig in several places of the ten-ario. In the ten-arium itself there is an artificial rock cavity made of Styrofoam (a few 15 x 30 x 15 cm.), that I have now filled up 2/3 with moist potting soil. The 14.06.2000 The female laid nine eggs of about 40 x 22 mm. It remained in the cavity for about a day. Then, not only was the egg well of the cavity filled with substrate, but the female pushed all the substrate of the terrarium on the artificial cavity, so that it finally disappeared under a mountain of substrate. Eggs were removed shortly after laying and placed in a Styrofoam box converted into an incubator., as described by WERNING (1995). Once the eggs are removed, the female scratched the cavity again to close it completely. For a week or so, seemed to guard the nest cavity and continued to move material up the mountain.

The incubation substrate was moist sand., with which he had already had good experience in laying eggs in the Chacahuala del Noroeste Sauromalus ater. I adjusted the humidity of the substrate with the "safe instinct" that I had already acquired with the other Chuckwallas. The sand is moist but not wet, humidity reaches approx. 90-95 % due to evaporation above the heat source in the brood box. Half of the eggs were buried in the substrate. No light enters the incubator except during controls.

During the first four weeks I incubated at 30ºC, the remaining 6,5 weeks at 32ºC. One egg died after about four weeks for no apparent reason. He seemed to have suddenly lost tension; had softened and yielded. The opening showed that she was fertilized. another egg, after eight weeks of incubation, also collapsed a bit and was without tension. Then I increased the humidity of the substrate a little, the egg recovered after a few days and was plump and firm again.

The 01.09.2000 the first eggs hatched. The 03.09.2000 the eight pups were born. The incubation period was, Therefore, of 80 to 83 days. CARL & JoNES (1979) inform of 94-99 days to 29-31 incubation temperature ºC. In my case, all the young animals first scratched the egg, from which the clear came. Only hours later they took the head out of the egg, followed by the upper body after a few more hours. The pups took a 24 hours to finally hatch. All hatchlings still had a large yolk sac, that were completely reabsorbed during the 48 following hours. During this time I left them in the incubator. The pups measured between 5,5 and 6,1 cm. in length and between 10,1 and 12,3 cm.. So, hatchlings were much smaller than previously reported in the literature (CARL & JoNES 1979: 7,2 cm., SYLBER 1985: 7,1 cm.). Egg sizes also remained below literature values. (CARL & JoNES 1979: 44 x 29 mm, SYLBER 1985: 50 x 35 mm), the smallest clutch size known so far was given by CASE (1982) with 14. But, according to the same author, the smallest female known so far to have reproduced, with a length of 24 cm., was already considerably larger than my female with 18 cm..

The newborn pups seemed very weak and barely moved, so I feared that they would not be viable. Once the yolk sac is completely reabsorbed, I placed them in the breeding room. In a few minutes they cheered, they ran around the tank, they caressed all the furniture and even nibbled on a piece of wood from a root.

The average breeding terrarium 100 x 60 x 50 cm and was equipped with two fluorescent lamps of 40 W and a focus of 60 W that illuminated a root from a distance of about 20 cm.. It also, juveniles were irradiated several times a week for 1-2 hours with an Osram Ultra Vitalux lamp.

The glass of the terrarium was replaced by a grid so that the UV rays were not filtered and the lamp was placed at a few 50 cm in front of tenarium. Young animals reacted immediately to radiation. They reached out and clung to the net to get as close to the radiation source as possible.. when they had enough, they gradually retreated to their hiding places.

In addition to the root mentioned, a small artificial rock from the shops and a stack of compressed cork sheets arranged in such a way that there were enough indentations to hide were used as furniture. The back and side walls are pasted over with decorative cork boards, which allowed the animals to climb the walls a little, although the little ones are already quite clumsy when climbing vertical surfaces. I initially chose quartz sand as the substrate, but after discussing with two terrarium keepers I decided to use only cellulose cloths (kitchen towels), as they both reported for their experience of death traps in young Uromastyx and Sauromalus, that had occurred due to clogging as a result of massive ingestion of sand.

feeding the little girl Angel Island chuckwalla did not cause any problems. From the first day in the breeding terrarium they ate all the vegetable food that was offered to them.. Feeding was similar to that of adults.. From the beginning, small crickets were offered, wax moth caterpillars and cockroaches for interest, but the chuckwallas ignored them. Today, they do not accept food of animal origin.

In December, the little ones chuckwallas were subjected to a three-week "mini-hibernation" with the lights off and at room temperature (a few 20 C).

At four months, I moved the young animals to a larger terrarium (150 x 70 x 100 cm.). So far no interactions between the animals have been observed., apart from occasional mutual nods. But, a young man lagged behind in growth. Only too late did I realize I wasn't eating enough. when i split it, he was already refusing food and died shortly after at five months. After nine months there were two more losses. One was apathetic and separated. Although he kept eating, died after a few days. The same day, another animal in the group died without any previous signs of disease. The necropsy revealed a massive salmonella infestation in both animals as the probable cause.. The swabs from the other animals showed the same results., and an antibiogram revealed the sensitivity of microorganisms to Baytril. treatment with Baytril was carried out successfully under veterinary supervision.

When buying a reptile with these characteristics, it is an obligation to make sure that the store where it is sold is certified and has the necessary permits according to the law so that you do not have any type of problem., if it complies and is in order, you make sure to buy an animal that is not in danger of extinction since they are surely from specialized farms for the sale of this particular species.

Please be aware and for no reason acquire animals in clandestine shops illegally or on the black market.. Since you favor the disappearance of species that are in danger of extinction.

1. Angel Island chuckwalla, Spiny chuckwalla (English).
2. Chuckwalla épineux (French).
3. Angel Island Chuckwalla, Stachelige Chuckwalla (German).
4. Chuckwalla espinhosa, Angel island chuckwalla, Ilha dos Anjos chuckwalla (Portuguese).
5. "Iguana espinosa", Chacahuala de la Isla Angel de la Guarda (español).