Reptile care info
Phrynosoma Asio Husbandry by Jeff Judd
This is a large, hardy species of Horned Lizard (HL) that does well in captivity. It has a good appetite and thrives on a varied diet. These are very sociable Horned Lizards, interacting to each other with head bobs, arm waves, and tail wags. They are aware of their surroundings, and can recognize humans as a food source; they will watch in anticipation as food is being offered, and will eat from your hand.
Terrarium:
GHLs should be housed in a glass terrarium. Overall, it should be long and wide but not very tall. Shallow tanks allow good ventilation and prevent heat from building up. The top of the substrate to the top of the terrarium should measure around 12 inches. The substrate level can be raised to accommodate a taller tank. The length and width needed depends on the number of GHLs that will be housed. However, the bare minimum for one or two adults should be 36" long x 18" wide.
Benefits of Large Tank:
No terrarium is too large. Generally, the bigger the terrarium is, the better. With adequate space, intense lighting can be provided them, as well as a wider range of temperatures for GHLs to properly maintain their preferred body temps. GHLs will be able to properly feed, and exhibit more natural behaviors. Also, you can create a more realistic landscape that will better resemble their natural environment.
What to add:
The bottom of the terrarium should be covered with three to six inches of sand. The sand should consist of various sized particles. Giant Horned Lizards purposely ingest specific sizes of these particles to aid in digestion. Rocks large enough for the GHLs to bask on should be placed under the heat lamp to provide basking sites. The cool side of the terrarium should contain plants or branches to provide areas for climbing. Suitable plants include many spineless cactus, succulents, palms, grasses, and non-toxic houseplants. Giant HLs are semi-arboreal, and during periods of inactivity, they will climb onto the plants or dead branches, or seek shelter under half-cut tree bark, cactus hollows, or sturdy rock formations.
Lighting:
The 160-watt or 250-watt mercury vapor heat lamps specifically designed for reptiles work very well for GHLs. They provide adequate levels of UV radiation as well as produce heat, which are both essential to keep GHLs healthy long term. Fluorescent lighting can be added if additional light is desired. The lights should be turned on and off by a 24 hour timer. They should be set to come on 13 hours a day May, June, July and August, 11 hours a day March, April, September and October, and then 10 hours a day November, December, January and February.
Temperature:
The terrarium should be placed in a room that stays between 65 and 75 º F year round. The heat lamp should be placed at one end of the terrarium while the other end remains unheated. The height of the lamp should be adjusted so that directly beneath the bulb the temperature is around 115 º F after the bulb has been on for an hour. This will provide a range of temperatures allowing the HLs to maintain their preferred temperature. No additional heating devices are needed after the lamp turns off, so the night temperatures should be falling between 65 and 75 º F.
Diet and Nutrition:
Giant Horned Lizards should be fed daily. They should be fed in the morning, or the late afternoon when they are most active. If they are fed in the morning, they should be allowed to warm up for about an hour beforehand. The insects should be placed in the same area of the terrarium at each feeding, because the Giant Horned Lizards will recognize a feeding area and look for food there. An individual’s appetite depends on its size, the time of year, and stress level. Generally, it is best to continue to feed the HL until it has no more interest in food.
Feeding:
In captivity, ants, crickets, or roaches should make up most of the diet with the occasional mealworms and waxworms. All of these insects are available commercially. Make sure the insects are from a clean source, otherwise they can harbor disease, which can be passed onto the GHLs. Crickets, roaches, and mealworms should be fed baby cereal and carrots before they are fed to the GHLs. The size of the insects is the most important aspect of feeding; they should be no longer than the width of the GHLs head. Feeding your Horned Lizards large insects can cause them to regurgitate it the next day, become very sick, or die.
Ants:
Ants (Pogonomyrmrex barbatus and Pogonomyrmrex rugosus) should be included daily. The ants available commercially from the genus pogonomyrmrex are eagerly accepted by GHLs. They should be kept in a large jar with a lid that has very small holes drilled into it. It's important to only put 3-5 ants in the tank at a time. Dumping large numbers in will cause the GHLs to panic, often resulting in the ants biting or stinging them. Immediately remove any GHLs, then the ants if this happens. If an ant latches on with its pinchers, it must be removed by crushing its head with tweezers then slowly pulling it off. Offer ants until the HL stops eating or showing interest. Remove any that are not eaten with forceps or large tweezers.
Other Insects:
Crickets (Acheta domestica) and roaches (Nauphoeta cinerea) can be offered every other day. They come in many sizes, and do well with both hatchling and adult GHLs. They can easily be gut loaded and coated with vitamin and mineral supplements. However, crickets can be difficult to catch unless their hind legs are removed. Mealworms can be offered once or twice a week. They are difficult to digest. The number offered needs to be closely monitored. No more than 3 or 4 should be offered at one feeding. The freshly shed mealworms are best. These are white in coloring, and should be fed to Giant Horned Lizars when they are available. Waxworms are large and high in fat, which may be harder to digest in large numbers. No more than one or two should be offered to adults, once a week.
This article is reprinted from web-page www.phrynosoma.org
Abronia, Captive Husbandry and Breeding Notes by Jason Wagner
Introduction
I’ve been keeping Abronia collectively for about 6 years, but have only been successful with breeding them for three years, from 2003-2006. I owe a great deal of gratitude to a professor in the Pacific Northwest who teaches Biology and shares my passion for working with the Abronia genus, but he prefers to remain anonymous. He was very helpful to me early on in providing basic husbandry guidelines for keeping this beautiful lizard species. My goal in documenting these notes on keeping Abronia is primary out of respect for the animals. I want to share my observations so that others who may have the opportunity to keep these lizards will at least have a reliable reference point from which they can work to gain there own experiences. Abronia have adapted to a unique environment in the niche habitats they occupy in the wild, and as a result their captive care and maintenance does take some special attention to detail, if one is to become successful working with them. I try to maintain a level of humility with the entire subject of captive husbandry, because in effect, all we are really attempting here is to mimic in as many ways as possible, what they would have in the wild (obviously without the dangers of predators and preferably without parasites). Try as we might, there is no way to duplicate their native environment exactly, but we can get close enough to be effective in producing them on a sustainable basis and in my book that is an achievement worthy of the effort.
Abronia taeniata, male Abronia graminea, male
Brief Natural History
Abronia lizards are found in several unique habitats but primarily inhabit cloud forests at high elevations in Central America, mainly in Mexico and Guatemala. They are also found in some instances in Oak scrub and Pine forest areas, also at high elevations. There are about 26 species known to Science depending on who you ask, and they are live bearing, producing a single litter each year. Because they are not common in their native ranges and are limited to small territories, there are some species which may have already gone extinct due to massive land clearing for agriculture or charcoal. In the wild they are mostly arboreal and usually live high in the trees, although I have found specimens on the ground and in rotting wood, or hiding in large clumps of moss. The trees they live on are generally large oak varieties, and are typically covered with moss, ferns, orchids and most importantly…bromeliads. They use the bromeliads as a micro-habitat for humidity, water, and shelter. They are found at high elevations, usually between 4000-8000 feet (1200-2500 Meters). At these high altitudes, there is a great deal of temperature variance between day and night, which is an important element to consider in captive husbandry, as I have found they will thrive best in a situation where they are provided with a strong night time temperature drop. The temps will range from as low as 40F and can be as high as 90F, but those are generally the extremes. In the cold season where they live, night temps can reach below 40 Degrees F ( 5 Celsius) for short periods of time and it may even snow on occasion. During these very cold seasons, the lizards have been found to den together in hollow trees full of rotting mulch, where the temps are likely around 50 F (10+°C). I assume that they don’t stay out in the open air exposed to such cold temps. The same principle applies for the hot season and high temps. They will seek out cooler shelters, like thick moss growing over a large rock in the shade…which may be 70 degrees F (20°C), when the ambient air temps are hovering around 90F (32°C). They are most active at temps around 75-80 F (25-28°C), and that is when you will find them basking or searching for food, typically in the morning hours from 9-11 am. On a mild sunny day, they can be seen basking later into the afternoon, usually in the trees. I believe its helpful to bookmark a weather website and monitor temps as well as rain patterns for Puebla, Mexico or Huehuetenango, Guatemala, as both of these climates support Abronia in the wild. Cloud forests by definition are commonly a misty, foggy, high humidity area and it is in this niche environment where Abronia thrive. These areas typically get a lot of precipitation, and on a frequent schedule. The mild climate also supports a large diversity of insects and my guess from captive observation is the Abronia take advantage of this. Breeding usually takes place from September – December and 7-14 babies are born typically from April-June.
Typical niche habitat of Abronia photographed in Mexican highland forest on a sunny day.
Enclosure Design
All-Screen cages are the best choice, as they provide adequate ventilation (think of a tree dwelling species) and the advantage of offering natural sunlight. Males should be kept separate, and will typically fight if kept together. Babies will also fight if kept too crowded. I have only seen females fight twice and it wasn’t too severe, mainly a nip to establish territory (Abronia vasconcelosii). I keep my animals in large screen cages, heavily planted with bromeliads and orchids, and offer plenty of climbing limbs or branches. The most important thing I give them is a 2-4 inch layer of long-strand sphagnum moss as substrate on the bottom of the cage. This provides moisture, and a cool area to retire from heat. The moss should be kept moist in some areas, not all wet all over, and should be dry in some areas. Occasionally I like to let the moss dry out completely, since that does happen in their native environment too…short dry-spells. The moss also has been documented as having a natural anti-bacterial property and was even used in World War I to transport organs, etc. UV light is thought to be important, and I would agree. I have noticed my lizards always look more brilliantly colored when they have had extended exposure to natural sunlight. Abronia graminea for example will typically fade to a grayish teal color if kept indoors under incandescent lighting with little temperature variance over a long period. In nature, they are usually a brilliant emerald green. I provide natural sunlight by moving the screen cages outdoors when the weather is good, but when kept indoors I offer a low emission UV light, that doesn’t put out a lot of heat. I use Arcadia compact fluorescents, UVB 7% in the hotter summer months and then switch to Active UV Heat bulbs (or similar) in the winter. These lizards will not do well if they are kept hot like a lowland tropical reptile. The high altitudes where they come from fluctuate a great deal in temperature, but they almost never go over 90 F (32 °C), and I would not allow them to be exposed to weather under 45 F (7°C) if I can help it. I have recently started keeping the cages on a Concrete slab, as I find that when the temps get too hot in the daytime, the moist moss resting directly on the flooring of the cage that is on the cool concrete, provides a cool temperature gradient that may be useful to the lizards. It is very important to provide shady areas within the cage if the animals are being housed outdoors. This can be achieved with broad leaf plants or cork bark slabs sitting at an angle in the enclosure. They will die if they are left in a hot cage left in full sun with no shade obstructions, and have no way to thermo-regulate from the pounding direct heat of the sun through the screen.
Food and Water
I make a special effort to offer a variety of insects. The favorites are large black diurnal crickets, followed by grasshoppers. They will also take green caterpillars, like hornworms, snails, spiders, meal worms, soldier fly larvae (phoenix worms – high in calcium content), roaches, etc. I often feed my Abronia by hand or with tweezers, as they can sometimes be a little pokey in their eating habits. When feeding lizards that are almost purely insectivorous like Abronia, I believe its important to be aware that they do not have the liver or kidneys equipped to deal with a high protein diet, for example like a snake that eats only mice. They instead will generally eat bugs that are full of plant matter themselves, like an arboreal caterpillar, grasshopper or katydid. When I offer crickets, I make sure they have eaten a good variety of leafy greens like kale, romaine lettuce, dandelions, and then I supplement that with fruits and vegetables. I also like to provide the feeder insects with a mix of ground up whole grains as substrate…essentially to “gut-load” the lizards food items with decent nutritional content. I do not recommend that Abronia be fed exclusively on store bought crickets that have been raised on chicken meal, which is a high protein diet for baby chickens. An occasional pink mouse is probably OK as a food item, but I have never offered one, and would definitely not over do that. I believe the variety in the insect diet plays some kind of important nutritional role for captive lizards.
I almost always spray mist daily the plants, enclosure sides, and lizards themselves if they are out. Additionally, 2-3 times a week, I will provide a dripper cup that drips about one cup of water over a plant in the enclosure so the lizards can drink at their leisure for a period of about 15 minutes. I use tap water that has sat out in an open bottle for 24 hours. Another watering method that I really like and am currently testing, is to use a “misty mate” pressure spray bottle. This high pressure system emits a fine mist over a period of up to 20 minutes and is excellent for simulating a cloud forest environment.
Breeding behavior and raising young
The Adults will typically breed in their second year, when they are full sized and sexually mature. I have seen breeding activity as early as August, and as late as November. The pair may stay “locked up” for as much as 24 hours. Babies are born in the months of April to June, typically. My females have produced 7, 11, and 13 babies at a time. In my experience, females will not eat their young, but I don’t trust the males or other adults. Gravid females will develop “chalk sacs” on the sides of her jowls before giving birth, likely as a calcium supply. She will also gain weight, noticeably. Perhaps the toughest part of keeping Abronia is raising the babies. They have all the same requirements as the adults, except they are smaller and have less body mass so they are more susceptible to over heating and death from high temps. I have found that anything over 85 F, is dangerous for them. They also may have little battles with each other over space so it is best to keep them in small groups, like 2 or 3 to an enclosure. I’ve tried keeping them separate in small “kritter keepers”, which seemed to work OK but they didn’t have optimum exposure to UV lighting or ventilation. However that was a good way to ensure they were catching and eating their prey. Finding and offering small insects on a daily basis seems to be very important for the first 3 or 4 months. This can be challenging. I’ve caught small grasshoppers by hand, and hunted for little green inch worms in the lawn, and used a net to do field sweeps, plus offer the normal crickets and smaller meal worms. I’ve also recently discovered soldier fly larvae (marketed and sold as “Phoenix worms”) which are a good size and move slowly enough to be devoured by the young. Plus they are high in calcium which is probably good at this stage. My best experience has been to keep the babies exactly as the adults in full planted screen enclosures. I had to use aquarium silicone to plug the small holes in the corners of the screen cages so the little crickets and bugs wouldn’t escape. It’s important to offer plenty of small insects daily, but don’t overwhelm them so that the crickets are constantly bothering them at night, for example.
Miscellaneous Notes
The number one killer in my opinion of Abronia, is allowing them to get too hot. If you don’t want them to breed, maintain them at room temperature constantly, and don’t drop the temps down at night. There seems to be a correlation with temperature variance and breeding success. Be wary of ants that can scout and mount surprise attacks, particularly with babies. I watch temps closely and keep my animals outside for about 5 months of the year, which I think contributes to their overall health, and reproduction.
Abronia are rare in the wild, and with their small native habitats under a considerable amount of pressure, in some cases to the point of devastation, I feel it’s important to do what we can to preserve them in captivity when we have that opportunity. The best solution would be to establish wild preserves in their native habitat where they can be safeguarded from the land clearing practices, etc. But as an alternate method of conservation, I see considerable value in learning how to establish them successfully in a captive environment.
We express our thanks to the author of this article Mr. Jason Wagner. To find more information about the captive management of these lizards please visit http://projectabronia.com/
Care and Captive Breeding of the Gidgee Skink, Egernia stokesii stokesii. Text and photos by Sascha Knauf
Long since the days of unrestricted export of Australian flora and fauna, captive breeding of Australian skink species has become established, although the supply of these lizards does not come close to meeting the great demand for them. With few exceptions, captive breeding of Australian skinks is practically problem-free as long as seasonal cycles are strictly maintained. This article reports specifically on the care and breeding of one species: the gidgee skink, Egernia stokesii stokesii.
Taxonomy
According to WILSON and KNOWLES (2000), the genus Egernia (the spiny-tailed skinks) comprises a total of 26 species, all but one of which are endemic to Australia and Tasmania. The species of Egernia can be further classified into seven groups, each named for the taxon that typifies it:
Egernia cunninghami-group
Egernia striolata-group
Egernia kingii-group
Egernia luctuosa-group
Egernia whitii-group
Egernia major-group
Egernia rugosa-group
Egernia stokesii belongs to the Egernia cunninghami-group, which includes a total of seven species of medium-sized to large skinks with strongly keeled scales. The tail is robust and covered with spiny scales, which the members of this group utilize in their characteristic defensive behavior.
Egernia stokesii is divided into four subspecies: the nominate Egernia stokesii stokesii (Gray, 1845); Egernia stokesii aethiops Storr, 1978; Egernia stokesii badia Storr, 1978; and Egernia stokesii zellingi (De Vis, 1884).
The common name "gidgee skink" is Australian. This species is also commonly known as the spiny-tailed skink. The species name is in honor of Admiral John Lort Stokes, an accomplished officer of the British Royal Navy who was serving on the HMS Beagle, under the command of Robert FitzRoy, when Charles Darwin made his famous voyage. The subspecies name "aethiops" basically means colorful (referring to the darker coloration), and the subspecies name "badius" comes from the Latin for reddish brown (STORR et al., 1981).
Housing in a group: a mated pair with one of their offspring
These skinks hide in crevices and block the entrances with their spiny tails to protect themselves from enemies. Pictured is a 2-year-old male
Description of the nominate form
Egernia stokesii stokesii is a medium-sized skink. The male reaches an average of 230 millimeters in total length; the female, 220 millimeters. COGGER (2000) gives the snout-vent length as 180 millimeters. In my own observation, there is usually a small but visible size difference between the sexes, the males being a little larger, but this is not grounds enough for positive sex- ing. In general, it is very difficult to distinguish between the sexes on the basis of external appearance. With experience and much observation of behavior, however, one can make a reasonable guess about whether a skink is male or female.
The nominate form of the gidgee skink has a chocolate- brown dorsal ground color, which can vary greatly in intensity from one individual to another. Reddish-brown specimens are also common. The limbs are often somewhat darker than the body. Small groups of beige, sand-colored, or sometimes white scales form spots at regular intervals along the body, and less on the head. Single black scales are also present. The pattern varies greatly between individuals, and depends on the patterns of the parents. Some specimens have a uniform coloration with no spots at all. The undersides are a light cream color.
The body is generally cylindrical and plump with strongly double- keeled dorsal scales. The tail is short, stocky, and somewhat dorsoventrally flattened - it is also extremely muscular and bears pines of up to a centimeter in length.
In general, this skink is well adapted to its environment and has a very imposing appearance.
Distribution and habitat
COGGER (2000) very generally describes the distribution of Egernia stokesii as being from the western coast to central and southern Australia; and also in southern Queensland and northwestern few South Wales.
More specifically, Egernia stokesii stokesii is found on the Houtman Abrolhos Islands, Western Australia (COGGER, 2000; HAUSCHILD and GASSNER, 1995; WILSON and KNOWLES, 2000). Egernia stokesii badia is found in south- western Australia. Populations have been described from Dirk Hartog Island in Shark Bay. The “eastern form” described by WILSON and KNOWLES (2000) said to be found in South Australia, western New South Wales, central Queensland, and southern Northern Territory. HAUSCHILD and GASSNER (1995) extend this distribution to include part of central Australia, and cite the species in all Australian states except Victoria. Egernia stokesii aethiops is known from Baudin Island in Shark Bay (COGGER, 2000; WILSON and KNOWLES, 2000). For the distribution of Egernia stokesii zellingi, COGGER (2000) gives eastern Australia.
These skinks all occupy similar habitats, with some variations across the vast range of the species. In general, the lizards habit areas with narrow crevices into which they can wedge themselves tightly for shelter from enemies. Egernia stokesii stokesii and Egernia stokesii aethiops are found mainly in limestone outcrops. Egernia stokesii badia, on the other hand, often prefers hollow dead tree trunks and limbs (WILSON and KNOWLES, 2000).
In a land with such extremes of climate, the choice of shelter is critical for the necessary thermoregulation of a reptile. Rock heats up quickly and holds warmth better than wood. Wood provides better insulation. In any case, the skinks often have little choice, and take refuge wherever they can.
Behavior
Hardly any other lizard group exemplifies as well as these skinks how perfectly anatomy and behavior can be adapted to habitat - and knowledge of the gidgee skink’s natural behavior is necessary for providing captive housing suitable for the species.
Egernia stokesii is very strongly territorial, and carries out practically all of its activities within its territory. This includes morning basking directly in front of its shelter. This species is strictly diurnal, and its daily activities in the wild correspond directly with the rhythm of the sun - and in the terrarium, with a suitable lighting regime.
The gidgee skink begins its day inside its night shelters. As soon as the morning sun (or terrarium lamp) has warmed the environment sufficiently, the skink emerges from hiding to bask until it reaches its preferred body temperature. After a long sunbath, the skink begins searching for food. It forages for vegetation, always staying within close proximity to the basking spot and shelter. Midday is spent digesting. If the day is too hot, the skink retires into its shelter. In the evening it forages again, tending to venture farther from the shelter than during the morning feeding. The day ends with the final rays of sunlight. Like some of the other species of the genus, Egernia stokesii tends to always defecate in a certain area of its territory. In the wild, this behavior can leave clear evidence of the presence of a nearby hiding place (HAUSCHILD and GASSNER, 1995) - and as regards predator avoidance, the reason for the behavior is not clear (GREER, 1989; COGGER, 2000). Coprophagy (eating feces) is common (pers. obs.), and serves to enrich the intestinal flora of the animal and increase digestive efficiency. Juveniles in a group eat specifically the feces of adults (pers. obs.).
If danger is perceived, the skink runs to its shelter as fast as possible. Once inside, the skink inflates its body by inhaling deeply, and blocks the entrance with its spiny tail - this posture makes it practically impossible for an enemy to pull the skink out (HAUSCHILD and GASSNER, 1995; GREER, 1989; COGGER, 2000; pers. obs.). Based on other species - e.g., Egernia kintorei or Egernia multi-scutata - it may be assumed that Egernia stokesii also prefers shelters with at least a second entrance (GREER, 1989), which should be taken into consideration when planning a terrarium.
In intraspecific combat, the gidgee skink lashes sideways with its powerful spiny tail, sometimes even with the rest of the body inside the shelter (pers. obs.). Territorial combat occurs not only between males, but also with unfamiliar females, and follows a specific routine. Threat displays include gaping with the mouth, inflating the body, and turning sideways. If the threat displays are not successful, the skinks resort to biting on the flanks, legs, and tail. If a confrontation reaches this stage in the terrarium it is a real problem because there is usually no way for the losing skink to escape. These skinks are merciless, and fighting continues until one of the rivals is killed or flees - in the terrarium such a battle usually ends in death.
But be careful. Mating behavior in Egernia stokesii is practically as violent as territorial fighting. The male is not at all gentle with the female. Many elements of combat behavior are also seen in mating behavior.
Life within the family group contrasts starkly with the violent territorial behavior. Several individuals often peacefully share the same shelter (HAUSCHILD and GASSNER, 1995; GREER, 1989). This can also be observed in the terrarium. Juveniles can even be raised together with their parents. The adults are clearly protective of newborn offspring. Unusual among reptiles, this species shows a mother-child relationship (MAIN and BULL, 1996). Under certain circumstances, behavior between unrelated skinks is different from behavior between related skinks.
However, the harmony within a group can change abruptly when juveniles, especially the males, reach sexual maturity and have no opportunity to establish their own territory. Conflicts generally arise between the father and his grown sons. In order for natural social behavior to be observed in captivity, the enclosure must provide sufficient space. Oppressed individuals should be removed from the group and housed individually for a recovery period before being housed together with others of its species. Who is housed with whom is a question of feeling. Usually mated pairs are the best cohabitants.
Portrait of a male
Housing
At the time of this writing I have 12 gidgee skinks: two mated pairs with offspring, and a group of juveniles. All are housed in wooden terrariums that measure 80 x 60 x 100 centimeters. The lower side and back walls are covered with plaster and used by the skinks for climbing. The substrate on the bottom is sand. Several heavy flat slabs of rock are stacked such that, together with the back wall, they form a system of crevices and galleries with more than one entrance. Large dead limbs complete the furnishing.
One of the author's terrarium setups. Ideally the back wall should be made of rock, but that was unfortunately not possible in this case for technical reasons. The entire top is covered with wire mesh, which, in conjunction with fans, provides optimal ventilation.
Overall lighting is provided with an 80-watt HQL lamp following the photoperiod illustrated in Figure 1. A spot lamp hangs just in front of the rock slabs to create a basking spot. The bulb is changed depending on the season. In spring and autumn a 25- to 40-watt bulb is sufficient; in summer I change to a 60-watt bulb. Another spot lamp can be mounted over a different exposed part of the enclosure. The skinks often bask together, climbing on and over each other even though there is plenty of space for both of them. An Osram 300-watt “Ultra Vitalux” lamp is used for 20 minutes a day to provide UV radiation, which the skinks readily bask in.
Figure 1: Hours of daylight per day adapted to central European conditions. This daily lighting regime has proved successful for raising gidgee skinks over a period of years. The gray bars represent the winter rest period. From the middle of November until the middle of February, the lights are turned off. Within a period of 2-3 weeks, hours of daylight drop from the shown to zero.
Under the spot lamps, the temperature reaches about 45°C (113°F). Overall cage temperature is generally maintained with these lamps, but a heat cable is also set under the substrate for use when necessary. Ideally a heat cable should be set underneath the floor of the terrarium (this protects the lizards in case any toxic fumes are produced from overheating).
Small water dishes are always available for the skinks to drink from. Air circulation is created with a ventilation system. The fan speed can be controlled to provide just enough air movement to avoid stagnant air but not produce draughts - vital for the health of the skinks.
In spring, the entire enclosure is lightly misted with warm water every day for a week, in the morning just after the lights are turned on. Thereafter spraying is reduced to every other day, and then 2-3 times a week in summer. The sprayed water should dry up within a couple of hours. In autumn I spray only very occasionally, especially when shedding begins. In winter, the terrarium is kept completely dry. This is important since dampness during overwintering can contribute to fungal infections that can be fatal.
The room in which the terrariums are set up is very light, and it is easiest to keep the Australian lizards under the conditions of Northern Hemisphere seasons. Since only captive-bred specimens are legally acquired, there is no problem of adaptation.
Egernia stokesii likes to climb a lot, and must be given the opportunity to do so in the terrarium. Stone- or plaster-covered side and back walls are good for providing additional climbing surfaces. If live plants are desired, grasses or hardy bushes are best, or even small eucalyptus trees, depending on the size of the enclosure.
Identification of the sexes
As already mentioned, the sex of a gidgee skink cannot be positively identified on the basis of external appearance alone (HAUSCHILD and GASSNER, 1995: pers. obs.). We can distinguish between invasive and non-invasive methods for identification of sex. The method chosen by the keeper will depend on time available and the health of the animal - non-invasive methods are preferred.
- Non-invasive sex identification.
A practical method for determining the sex of an individual (that is sexually mature!) is to place a known male adult into the enclosure with the skink of unknown sex. If necessary this can be done with a known female adult. By carefully observing the behavior of the two skinks together - aggression, copulation attempts, etc. - you can determine the sexes with an accuracy of about 85 percent (personal experience). This works only with animals that are really adults - i.e., at least 3 years old.
Massaging the cloacal region can produce eversion of the hemipenes, but if this does not happen you still don't know if the animal is male or female. This method takes skill (that comes with practice), and cannot positively identify a female, but it may be useful in conjunction with observing behavior.
- Invasive sex identification.
The method of probing used for sexing snakes cannot be used in spiny-tailed skinks. The tail of the skink is so muscular that the probe could not be inserted without enough force to damage the sex organ.
Endoscopy is a method of sexing that is 100 percent accurate (SCHILDGER, 2000), but it has drawbacks. The body cavity must be opened, which requires that the animal be anesthetized. This is most practical with the larger species of skink. An advantage is that other organs can be inspected at the same time. Conversely, if an endoscopic examination is indicated for medical reasons, the sex of the animal can be verified at the same time.
A more elegant method of sexing a lizard is by DNA analysis. This has been done for years with birds. The invasive aspect of this method is drawing blood or taking a tissue sample. As is commonly done with other lizards, blood can be drawn from the ventral tail vein - this should be done by a person with experience.
Care and breeding
Keeping and breeding Egernia stokesii requires adherence to a clear maintenance regimen. Seasonal changes must be marked in order to trigger the natural yearly cycle of the animals. In this way, reproductive behavior is synchronized among breeder specimens. Also, the winter rest period is necessary for restoring the general health of the individuals. The following should be provided:
- A clear daily cycle of light and darkness.
- An annual cycle of changing day length.
- A clear annual cycle of temperature changes to simulate the seasons.
- A clear annual feeding cycle respecting individual and seasonal needs (e.g., breeding season, gravidity, etc.).
- Optimal nutrition including vitamins and minerals.
Breeding is usually also successful under less rigid maintenance conditions (HAUSCHILD and GASSNER, 1995), but problem animals can usually be conditioned to reproduce if raised with these points taken into consideration.
In addition to the benefits for reproduction, annual cycling also generally increases the well-being of the animals. Remember that the biorhythms of the lizard are determined by the dynamics of their environmental conditions. Even captive-bred animals show behavior important for survival in the wild, such as hibernation, when temperatures and light (intensity and duration) decrease. The winter rest period corresponds with a time when food is scarce and temperatures and sunlight are insufficient for maintaining a body temperature necessary for activity. However, it is also important as a period of physiological conditioning and restoration, so should be part of the annual cycle in captivity as well.
After the winter rest period, when day length and temperatures increase in spring, the captive- bred gidgee skinks soon begin mating activity. The male follows the female around the terrarium. Biting on the tail and flanks is meant to keep the female from getting away, and to stimulate her receptivity. Meanwhile, the male continually attempts to gain a grip on the female’s neck. In his courtship biting the male seems to be quite brutal, but this is apparently normal behavior for this species. Even receptive females are bitten, and the bites may draw blood - these wounds generally heal well without medical treatment. Bite wounds on the neck of the female are often the first sign that copulation has taken place (HAUSCHILD and GASSNER, 1985; pers. obs.).
Offspring are born about 3,5 (HAUSCHILD and GASSNER, 1985) or 4 months (pers. obs.) after successful copulation. Much has been published regarding litter size for Egernia stokesii stokesii. MAIN and BULL (1996) report a total of 53 offspring born to 12 females in litters of 2-7 (average, 4.4) babies each between 18 February and 30 March 1994. It should be noted that all of these females were taken from the wild between December 1993 and February 1994, namely the same season as the births - meaning that they had copulated in the wild. They had been kept in outdoor enclosures until the end of February (end of summer in the Southern Hemisphere). In any case, these litter sizes are about the same as what I have observed in terrarium breeding.
When raised separately from their parents, for whatever reason, juveniles can be kept under the same terrarium setup and conditions as adults. Juveniles of the same age can be kept in groups until they reach sexual maturity. Thereafter, they may start fighting. I prefer to keep juveniles in pairs. If fighting starts as they grow, partners can be changed in an attempt to establish breeding pairs of unrelated individuals.
In my experience, a terrarium for raising a pair of juvenile gidgee skinks should measure no less than 40 x 70 x 50 centimeters.
In smaller terrariums, even with careful hygiene, the air tends to overheat and become stuffy, increasing the chances of illness.
Egernia stokesii stokesii can be bred at 3 or better 4 years of age. Breeding at a younger age is usually harmful for the female - birthing complications are common.
Diet
Proper nutrition of reptiles is a very broad and important topic that cannot be covered thoroughly in this article. Unfortunately, the available literature on the subject contains many contradictions as well as fabulous recipes for mixing the perfect, convenient, all-in-one feed. The ease for the keeper is often given more importance than the nutritional needs of the animals. Most captive animals are not extremely badly fed, but very few are extremely well fed!
Diet largely determines the success or failure of keeping and breeding these lizards, and should be entirely designed for the particular needs of the species. The gidgee skink is an omnivorous lizard. Its digestive system is intermediate between that of an herbivorous lizard and that of a carnivorous lizard. The ability to eat both plant and animal foods allows the gidgee skink to eat whichever food it can find, and thereby survive in its natural habitat.
But what about in the terrarium? To answer this question, it is important to understand that the captive skink need not be given the exact same types of foods that it would find in its Australian habitat, but it does need to be given the same proportions of nutrients. The proper balance of proteins, carbohydrates, fats, vitamins, minerals, trace elements, and fiber is crucial for the health of the skink. Cat food is much too high in protein and can lead to kidney problems in reptiles.
As in herbivores, fiber is important for digestion in the omnivore - involved in maintaining a healthy intestinal flora for the natural breakdown of certain nutrients. Remember that coprophagy is also involved in maintaining intestinal flora. Parasite management is therefore important - a veterinary examination should be done at least twice a year for animals kept in terrariums, and more often for animals kept outdoors in summer (which is preferable). Treatment should be specific to the particular parasites found.
Fiber in the diet not only increases the bulk of feces, but also changes its structure, creating more surface area on which digestive microorganisms can work, and thereby increasing the ability of the animal to absorb nutrients from food ingested. Intestinal flora is kept in balance, and undigested fiber helps to clean out the digestive tract, further contributing to efficient nutrient absorption.
Every week I give the skinks a supplemental handful of fresh meadow hay chopped into 1-centimeter lengths and enriched with powdered calcium and vitamin supplement. The skinks immediately begin nibbling on leaves and stems. Caution is advised when giving supplements. Overdoses of fat-soluble vitamins (A, D, E, and K) can lead to severe health problems. Calcium should be given in the proper proportion to phosphorus. Too much calcium is just as bad as a calcium deficiency. A good way to supplement calcium in the diet, especially for gravid females, is to scatter crumbled eggshell on the floor of the terrarium. Occasionally an entire hard- cooked egg can be chopped up, shell and all, and mixed with greens.
Food should always be given at room temperature. Vegetables given straight out of the refrigerator are too cold, and can lead to digestive problems or even death.
In the wild these skinks have fresh green vegetation available for only a short period of the year. Most of the year they must make do eating dried plants. Many herbivorous or omnivorous terrarium animals are given a diet too high in fruits or vegetables (such as lettuce) that are high in water content and low in fiber. The water is quickly absorbed, and the remaining intestinal content has little volume with little surface area, resulting in inefficient digestion. These conditions tend to favor pathogens rather than “good” intestinal microorganisms, resulting in an overworked and thereby compromised immune system. The lizards initially show no external symptoms of their weakening condition, but they become increasingly vulnerable to illness. A diet high in fruit, specifically fruit sugar, raises the risk of yeast infections.
Leafy branches of fruit trees or shrubs can be placed in the skink terrarium. The animal will busy itself nibbling away every leaf. Be careful not to use toxic plants, either as food or planted in the terrarium.
These animals eat the leafy parts of the hay and use the rest for hiding. Putting a couple of mealworms in the hay will keep the lizards busy for a while
For the animal portion of the diet, the skinks can be offered the usual insect prey commonly given to captive reptiles. Giant mealworms (Zophobas) are especially good sources of protein for gravid females, but even in this case care should be taken not to overfeed these rich food items. If insect prey is raised at home and fed vitamin and mineral supplements, additional nutritional supplements should be given to the skinks only if absolutely necessary.
King mealworms (Zophobas morio) are a favorite food of the captive gidgee skink
Simply by providing a well-balanced diet for captive gidgee skinks, it is surprising how interesting the behavior of the animals can become.
Acknowledgments
Special thanks to Alexandra Hofer for taking care of the gidgee skinks during the weeks when I could not be at home.
Bibliography
COGGER. H. G. 2000. Reptiles & Amphibians of Australia. 6th edition. Reed New Holland.
GREER, A. E. 1989. The Biology & Evolution of Australian Lizards. Surrey Beatty & Sons Pty Limited, Chipping Norton NSW.
HAUSCHILD, A., and P. GASSNER. 1995. Skinke im Terrarium. Landbuch, Hannover.
MAIN, A. R., and C. M. BULL. 1996. Mother-offspring recognition in two Australian lizards, Tiliqua rugosa and Egernia stokesii. Anim. Behav. 52: 193-200.
MULLER. M. J. 1996. Handbuch ausgewahlter Klimastationen der Erde. Forschungsstelle Bodenerosion der Universitat Trier Mertesdorf (Ruwertal), Trier.
SCHILDGER, B. 2000. Die Anwendung bildgebender Verfahren zur Geschlechtsbestimmung bei Reptilien. Praktischer Tierarzt 81(2): 150-160.
STORR, G. M., L. A. SMITH, and R. E. JOHNSTONE. 1981. Lizards of Western Australia - I. Skinks. University of Western Australia Press with Western Australian Museum.
WILSON, S. K., and D. G. KNOWLES. 2000. Australia's Reptiles - A Photographic Reference to the Terrestrial Reptiles of Australia. Collins Publishers, Australia.
This article was published in the magazine "REPTILIA" No. 51 April 2007
Instruction to customers - Testudo horsfieldii
ACCLIMATING AND KEEPING TESTUDO HORSFIELDII HEALTHY: USEFUL HINTS FOR IMPORTERS
FOREWORD
BION Terrarium Center deals with import-export, keeping and breeding reptiles since 1993. An important goal of our professional activity is ensuring proper and responsible keeping of the animals by our customers.
No matter from which source tortoises originated – “W”, “F” or “C” – all of them are delicate and vulnerable to stress creatures which need proper care. In fact, all tortoises we are shipping to you are supervised by our veterinarian and are clinically healthy (i.e. have no visual signs of disease like light weight, running nose, etc). Meanwhile to make our customers happy we definitely must cooperate closely with them.
Please keep the information below at hand before receiving tortoises.
1. KEEP ALL TORTOISES IN QUARANTINE FOR AT LEAST 2 WEEKS AFTER DELIVERY FOR FULL ACCLIMATION. PLS REMEMBER THAT ANY SHIPPING IS STRESSFUL FOR ANY TORTOISE;
2. SOAK ALL TORTOISES IN WARM SHALLOW WATER WITH REHYDRON SOLUTION FOR 20 MINUTES SHORTLY AFTER DELIVERY. WATER SHOULD BE CHANGED FOR EACH LOT OF TORTOISES;
3. AVOID DRAUGHTS IN YOUR FACILITIES. DRAUGHTS CAN EASILY CAUSE PNEUMONIA;
4. AVOID KEEPING TESTUDO HORSFIELDII MIXED WITH OTHER TORTOISE SPECIES OR USING FACILITIES WHICH ARE NOT PROPERLY DESINFECTED;
5. DON'T KEEP TORTOISES OVERCROWDED;
6. PROVIDE PROPER LIGHTING & HEATING GRADUALLY WITHIN 2 DAYS AFTER ARRIVAL. KEEP IN MIND THAT TORTOISES NEED PROPER LEVEL OF HEAT, LIGHT & ULTRAVIOLET TO STAY HEALTHY AND STRONG. GOOD SOLUTION MIGHT BE KEEPING TORTOISES OUTDOORS DURING SUMMER TIME PROVIDED DAY TEMPERATURE IS MINIMUM 25ºC AND NIGHT TEMPERATURE IS AT LEAST 20ºC. KEEPING TORTOISES IN OUTDOOR FACILITIES REQUIRES ENOUGH SPACE & SHELTERS. IN THIS CASE YOU DON'T NEED TO PROVIDE HEATING, LIGHT AND ULTRAVIOLET ARTIFICIALLY. PLEASE KEEP IN MIND THAT TORTOISES ARE EXCELLENT DIGGERS;
7. DO NOT FEED TORTOISES WITH FRUITS & VEGETABLES AS A BASIC FOOD. GIVE THEM AS A BASIC FOOD MIXED GRASSES (HAY) + DANDELIONS, KALLE, LETTUCE, PARSLEY, etc. TOGETHER WITH BASIC FOOD YOU CAN ALSO GIVE THEM FRESH TOMATOO, APPLE, PEAR, RED & GREEN SWEET PEPPER, CUCUMBER IN REASONABLE AMOUNTS 3 TIMES A WEEK. MIX ALL TOGETHER AND APPLY LIBERAL QUANTITY OF CALCIUM SUPPLEMENT;
8. DON'T KEEP WATER IN FACILITIES ON A REGULAR BASIS;
9. CHECK ALL TORTOISES ON ARRIVAL. IN CASE YOU FIND ANY WEAK OR SICK TORTOISES PLS LET US KNOW WITHIN 48 HOURS. DURING QUARANTINE PERIOD, CHECK ALL TORTOISES DAILY TO SELECT WEAK AND SICK ONES (IF ANY). IMMEDIATELY PUT THEM IN SEPARATE ROOM FOR TREATMENT;
10. PREPARE PROPER ROOM FOR TORTOISES ACCORDING TO THE SIZE AND QUANTITY WELL IN ADVANCE BEFORE ACCEPTING THE SHIPMENT. DON'T USE CAGES FOR BIRDS AND RODENTS AND AQUARIUMS AS FACILITIES FOR TORTOISES;
11. IF YOUR TORTOISES WANT TO DIG - LET THEM DO SO THROUGH PROVIDING ENOUGH SUBSTRATE;
12. IF YOU PLAN TO KEEP TORTOISES FOR A LONG TIME PLS KEEP IN MIND THAT THEY'LL NEED WINTER HIBERNATION;
13. PLS SEND THESE INSTRUCTIONS TO YOUR CUSTOMERS BEFORE SELLING TORTOISES. EXPLAIN THEM YOU WOULD NOT ACCEPT CLAIMS IN CASE OF IMPROPER KEEPING. IF SOMEONE DOESN'T INTEND TO OFFER RESPONSIBLE CARE - IT IS BETTER TO AVOID THE ORDER. IT IS IMPOSSIBLE TO KEEP A TORTOISE IN THE ROOM LIKE CAT OR DOG. ALL TORTOISES NEED SPECIAL FACILITY, PROPER HEAT, LIGHT AND FOOD. MEANWHILE WHEN KEPT PROPERLY TORTOISES CAN BE KEPT FOR MANY YEARS AND EVEN BREED;
14. IN CASE YOU ARE A WHOLESALER AND HAVE ALREADY CONFIRMED ORDERS WITH OTHER CUSTOMERS WE CAN MARK BOXES PROPERLY WITH SEPARATE ORDERS AND YOU'LL JUST FORWARD THEM ALONG TO YOUR CLIENTS TO AVOID EXTRA STRESS;
15. THIS INFO COULD BE USEFUL WHEN KEEPING OTHER TORTOISES SPECIES AS WELL.
