Archives of The Cold Blooded News

The Newsletter of the Colorado Herpetological Society

Volume 29, Number 8;   August, 2002

Reproduction and Captive Husbandry of Argus Monitors

by Gary Quirk

Now, the common name of this species is derived from numerous "eye-shaped" spots in the animal's pattern. Argus, meaning "all or many eyes" in Greek mythology or ARGUS, a giant with 100 eyes!

Since these are burrowing animals, you need to provide a deep substrate or provide, at minimum, a nesting box filled with 3 feet or more of soil as an outlet for their digging behavior.

Temperatures and Light Cycles: I provide my animals with a basking spot of 115 to 130 degrees. This needs to be accomplished with multiple lights (it's difficult for a four foot long lizard to fit its body beneath one light). I believe the ideal situation is to allow for a cooler area (80 degrees or less) as well as a basking area without needlessly raising the ambient temperature to extremes in order to ensure proper thermal regulation.

I use a 14 on, 10 off, light cycle, year round, except for a short winter cooling period, during which I provide a 12 on, 12 off cycle, with night-time low temperatures safely allowed to reach 57 to 58 degrees. I DO NOT PROVIDE UV LIGHTING, as I do not believe in it! (As, with humans who require a certain degree of intensity in their exposure to light [to alleviate depression], I believe it is the INTENSITY of light sources that is necessary to maintain healthy animals and promote reproduction. I acknowledge the dietary need for vitamin D-3 assimilation in some species, but this can be accomplished through proper and varied supplementation {as every species of Gecko/lizard bred in captivity through numerous generations has been successfully accomplished somewhere with no UV lighting.})

Diet: I am a firm believer in feeding whole prey items; however, I have used the popular San Diego Zoo ground turkey diet with success, but I try to keep the ratio at less than 30% of the overall diet (mainly consisting of rodents and chicks). I do not provide vitamin supplementation to adult/juveniles on whole prey rodent diets.

Conditioning: Well-conditioned, heavily fed, animals will produce year round without being "cycled". Although not required, I believe a short winter cooling period is conducive to overall health, especially to avoid metabolic "burn-out." Females should be fed heavily (i.e., three times a week), while males do fine on twice a week feedings.

Introduction: I normally put the male into the female's cage, but have had success both ways. A female will generally prove to be receptive after an initial period of 1 to 4 hours. During this period the female may show aggressive, unreceptive behavior before settling down and displaying receptive behavior (i.e., tail lifting, responding to males advances). However if at the end of 4 hours the female continues displaying aggressive and/or unreceptive behavior, separate them. If receptive to each other, leave them together between feedings. (Do not attempt to feed them together!) Repeat this for 7 to 10 days, then separate them.

Egg Deposition: This usually occurs 30 to 45 days following copulation. Make sure that a suitable nest box is available. If not, a female Argus will do one of two things: She will either nest improperly and most of the eggs will be infertile or, worse, she will not deposit the eggs at all. (The eggs will absorb some of the female's body fluids, swell, blocking the oviduct, ultimately killing her.)

48 to 72 hours prior to deposition, the female's pelvic area will become noticeably distended, even appearing as if she has already laid her clutch. (Note: I have observed up to 4 subsequent clutches laid from a single breeding, with fecundity dropping off each time.)

Incubation: I use Perlite as an incubation medium, maintaining 100% humidity. The eggs can be incubated at 84 to 90 degrees, with the duration of the incubation being 180 to 210 days depending, respectively, on temperature used. Eggs normally dimple 24 to 48 hours prior to piping, with neonates emerging 24 to 48 hours later.

Care of Hatchlings: I maintain hatchlings separately in ten- gallon aquariums with cypress mulch as the substrate, with a basking spot of 120 to 140 degrees. They feed on dusted crickets to about 6 weeks of age, at which time, they will normally start accepting appropriately sized rodents.

In conclusion, I believe the Argus monitor to be a highly interesting, albeit somewhat challenging, addition to any avid herper's collection.