Each species of reptile has gradually evolved over the course of millions of years to be very good at living in a very particular environment. Even for those that are fairly adaptable, such as ocellated skinks, their health and wellbeing is still heavily dependent on the environment that they’re living in. If you look at a map of ocellated skink distribution, you’ll notice that although they’re quite widespread, they more or less stick to the same type of habitat in each location. So, when you’re planning to bring home a pet ocellated skink, you need to make sure that its enclosure replicates the conditions of its preferred habitat.
Once a suitable enclosure has been selected, the habitat replication process starts with mimicking the effects of the Sun through lighting and heating equipment. Sunlight is complex, but if we simplify it, we can divide it into the 3 general components that are most important for successful reptile husbandry: infrared (heat), visible light, and ultraviolet radiation. Each component plays a different role in reptile health and wellbeing, which science is just barely beginning to understand. If you are interested in learning more about the relationship between reptiles and light, “Fire — The Sun: Its Use & Replication Within Reptile Keeping” by John Courteney-Smith is a great place to start.
Day Length for Ocellated Skinks
If you want to keep it simple, you can keep your ocellated skink’s lights on for 12 hours/day year-round. However, light plays an important role in hormonal cycling in reptiles, and hormones play a critical role in reptile wellbeing (and animal wellbeing in general). Instead of using a static day/night cycle, ReptiFiles recommends a dynamic day/night cycle of increasing and decreasing daylight over the course of a year according to the geographical location of a reptile’s natural habitat. This encourages more natural hormonal cycling in captivity, and hopefully, better long-term health as a result.
Here is a proposed day length schedule for ocellated skinks, based on day length data from Jerusalem, Israel, which is roughly in the middle of the northern and southern extremes of the species’ range as reported by iNaturalist and Kornilios et. al. (rounded to the nearest 5 minutes):
- January — 10 hours, 5 minutes
- February — 10 hours, 40 minutes
- March — 11 hours, 30 minutes
- April — 12 hours, 30 minutes
- May — 13 hours, 25 minutes
- June — 14 hours, 5 minutes
- July — 14 hours, 10 minutes
- August — 13 hours, 40 minutes
- September — 12 hours, 45 minutes
- October — 11 hours, 50 minutes
- November — 10 hours, 55 minutes
- December — 10 hours, 15 minutes
If you live in the southern hemisphere, then this schedule will need to be flipped upside-down to match with your local seasons.
The easiest way to schedule when your lights turn on/off is with a smart plug or digital outlet timer. I prefer to schedule each of my lamps and heat sources individually, so I recommend the Kasa Smart Power Strip or Zilla Digital Power Center for convenience. Aside from being better for your reptiles, using timers also makes reptile keeping that much easier!
Ocellated Skink UVB Requirements
UVB stands for “Ultraviolet-B”, and it’s one of the three types of ultraviolet radiation produced by the Sun. Many people freak out about ultraviolet because it’s strongly associated with sunburns and skin cancer when humans over-expose themselves to it. And when they hear the word “radiation,” they think about nuclear fallout and catastrophic meltdowns at nuclear power plants. But there are many different types of radiation, and while some are harmful, others can be beneficial.
UVB is a type of ultraviolet radiation that is essential to reptile health in both the wild and in captivity. One of its most well-known functions is enabling the synthesis of vitamin D within an animal’s body. But it also has many other benefits, including strengthening the immune system and stimulating the production of the feel-good hormone serotonin.
A good ocellated skink enclosure MUST include access to appropriate amounts of UVB. In order to meet this requirement, you will need a strong, high-quality UVB lamp, mounted at a safe distance from the basking area in a wide-angle reflective fixture.
How to use UVB with ocellated skinks
Ocellated skinks are classified under Ferguson Zone 2. If you have a Solarmeter 6.5 (recommended), the UVI on the basking surface should be between 2.0-3.0. UVI should be highest at the basking spot and lower in other areas of the enclosure so your lizard has options to choose from.
If you don’t have a Solarmeter, here’s a fair guide to distancing with each bulb type. The given distances are the distance between the lamp and the ocellated skink’s back while standing on the surface closest to the UVB lamp:
- Arcadia T5 HO Forest 6% OR Zoo Med T5 HO Reptisun 5.0
- mesh: 10-13″ / 25-33cm
- no mesh: 14-17″ / 35-43cm
- Arcadia T5 HO Desert 12% OR Zoo Med T5 HO Reptisun 10.0
- mesh: 16-20″ / 40-50cm
- no mesh: 20-26″ / 50-70cm
Your ocellated skink’s UVB bulb should span roughly half the length of the enclosure, no less than 1/3 and no more than 2/3. The fixture should be mounted over the basking area, alongside the heat lamp.
The above estimations assume a ~35% mesh block and come from bulbs installed in Arcadia ProT5 or Vivarium Electronics fixtures. For more details on adjusting basking distance based on mesh obstruction, see the Facebook group Reptile Lighting > Guides > Guide 1: Using T5-HO lamps above a Mesh Screen.
Due to reported unreliability in performance, ReptiFiles does not recommend ANY other brand of UVB bulb at this time. Using other brands of UVB lighting without the use of a Solarmeter 6.5 may negatively affect your skink’s health.
Note: Make sure that your UVB lamp fixture doesn’t have a piece of glass or plastic to “protect” the bulb. UVB rays are blocked by glass and plastic, rendering that bulb you just spent so much money on completely useless. Naked UVB bulbs are effective UVB bulbs!
Can vitamin D3 supplementation be used instead of UVB lighting?
In theory, yes. Certain species of reptile where UVB is considered “required” have reported been successfully bred while using vitamin D3 supplements rather than UVB. However, successful reproduction that does not necessarily mean that this is best practice. Aside from missing out on the other benefits of UVB, attempting to provide the perfect amount of vitamin D3 through diet alone is an imprecise science at best. Physiological need for vitamin D3 fluctuates from day to day and according to an animal’s species, life stage, and size.
When reptiles have access to appropriate amounts of UVB radiation, they are able to manufacture the exact amount of vitamin D3 that their bodies need in that moment. When reptiles only have access to vitamin D3 through diet, they are limited to the amount available. If there’s not enough, physiological processes that require vitamin D will be compromised. If there’s too much, excess vitamin D will get stored in fat cells for later use, creating the potential for overdose in the future. Considering that modern science doesn’t even know exactly how much vitamin D humans need — much less ocellated skinks — relying on dietary supplementation is most likely to result in under- or over-dosing the animal, both of which will negatively affect their health over the long-term.
To summarize: Rather than messing around with supplements, it’s best for your skink’s wellbeing to simply focus on providing appropriate amounts of UVB from a high-quality lamp.
General Lighting for Ocellated Skinks
Considering that ocellated skinks are primarily diurnal (day-active) and tend to be intermittently active all day long, it is reasonable to assume that they prefer and are stimulated by the presence of bright light in their environment. This assumption is supported by my own observations.
Although UVB lamps and heat lamps (we’ll get to that later) do produce some visible light, they simply don’t produce enough to get anywhere close to replicating daytime illumination. Furthermore, additional lighting is essential to growing live plants. For these reasons, ReptiFiles strongly recommends using ~6500K T5 HO or LED lighting, 2/3 to 3/4 the length of the enclosure.
Here are ReptiFiles’ favorite “daylight” lamps for ocellated skinks:
DO NOT use colored lights of any kind with your ocellated skink’s enclosure (red, black, blue, etc.), not even during the night. These can potentially negatively affect your lizard’s mental health by altering their perception of color in their environment and interfere with their circadian rhythm. Plus, it just looks weird and unnatural.
Keep reading about ocellated skinks:
- Introduction to Ocellated Skinks
- Shopping list: Supplies You Will Need
- How to Select and Buy a Pet Ocellated Skink
- Enclosure Size & Roommates
- Lighting & UVB Requirements
- Heating Requirements
- Humidity Requirements
- Substrate Options
- Environmental Enrichment: Decorating the Enclosure
- Feeding Your Ocellated Skink
- Handling Tips & Behavioral Notes
- General Health Guide
- Additional Resources