Keeper timer setting
T5 UVB: one hour later on, one hour earlier off
During active care — ON: 1 hour after daylight starts.
OFF: 1 hour before daylight ends.
During hibernation / full brumation: T5 UVB OFF (0 hours). In transition months, keep UVB off while dormant and use the active timer only once the animal is warmed and active.
October: daylight 11 h 45 m; T5 UVB 9 h 45 m.
The active T5 duration is the photoperiod minus two hours. Example: daylight 08:00–20:00 means UVB 09:00–19:00. Follow the monthly UVI strength measured beneath the tube and provide access to shade. This timing rule does not introduce hibernation for species whose schedule has only a mild or active winter rest. If an older combined heat / UV column is present, the new T5 UVB duration column governs UVB timing; existing heat settings are preserved.
UVI beneath the optional T5 tube
Working exposure targetOctober target at normal back height
UVI 4directly under the tube when it is on
The retained range remains a provisional captive working target. No new species-specific result was found that clearly requires a numerical change. Retaining it is not certification of an experimentally established optimum.
Your measuring point
Measure at the animal's normal back height directly beneath the brightest accessible part of the T5 strip, positioned toward the middle/back. The animal can enter and leave this area freely.
Keep a lower-UVI gradient and fully covered refuges near UVI 0. This is the optional exposure area, not the average across the cage.
Use a UV Index meter, such as a Solarmeter 6.5/6.5R. Warm the tube for about 30 minutes; keep reflector, guards and mesh in place. Raise or lower the fixture within its manufacturer's minimum-distance guidance, then recheck the reading and every higher accessible surface.
Evidence level: Provisional retention. These are working recommendations, often inferred; exact species optima and seasonal UV dose usually have not been measured. Log lamp-on time and animal behaviour as well as UVI.
Baines et al. (2016), UV-Tool · Muryn, Baines and Dishman (2026), Reptile Lighting Guide V10
October management
Selected automatically using the Netherlands date
Autumn taper
Rocky volcanic slopes, scrub, gardens and agricultural edges - endemic to Gran Canaria, Canary Islands
23-27 CDay ambient
18-21 CNight
38-41 CBasking
4T5 UVI*
11 h 45 mPhotoperiod
9 h 45 mT5 UVB duration
50-65 / 60-75%RH day / night*
Light spray 1-2x/wkSpray / rain
3-4Food offers*
Annual schedule
Scroll sideways on smaller screens
| Month | Day ambient | Night | Basking | T5 UVI* | Photoperiod | T5 UVB duration | RH day / night* | Spray / rain | Food offers* | Status / breeding |
|---|---|---|---|---|---|---|---|---|---|---|
| January | 19-22 C | 14-17 C | 30-33 C | 2-3 | 10 h 30 m | 8 h 30 m | 55-70 / 65-80% | Light spray 1-2x/wk | 2-3 | Cool winter rest |
| February | 20-23 C | 14-17 C | 31-34 C | 2-3 | 11 h | 9 h | 55-70 / 65-80% | Light spray 1-2x/wk | 2-3 | Winter rest / conditioning |
| March | 21-25 C | 15-18 C | 35-38 C | 3-4 | 11 h 45 m | 9 h 45 m | 50-65 / 60-75% | Light spray 1-2x/wk | 3-4 | Warm-up / courtship begins |
| April | 22-26 C | 16-19 C | 38-41 C | 4 | 12 h 30 m | 10 h 30 m | 45-60 / 55-70% | Light spray 1x/wk | 4 | Courtship / mating |
| May | 24-28 C | 17-20 C | 40-43 C | 4-5 | 13 h 15 m | 11 h 15 m | 40-55 / 50-65% | Minimal spray | 4-5 | Peak mating / vitellogenesis |
| June | 25-29 C | 18-21 C | 41-44 C | 4-5 | 13 h 45 m | 11 h 45 m | 40-55 / 50-65% | Minimal; moist nest only | 4-5 | Oviposition begins |
| July | 26-30 C | 19-22 C | 42-45 C | 5 | 14 h | 12 h | 40-55 / 50-65% | Minimal; water always | 4-5 | Main laying / incubation |
| August | 26-30 C | 20-22 C | 42-45 C | 5 | 13 h 30 m | 11 h 30 m | 40-55 / 50-65% | Minimal; water always | 4 | Late laying / hatching |
| September | 25-29 C | 19-22 C | 40-43 C | 4-5 | 12 h 45 m | 10 h 45 m | 45-60 / 55-70% | Light spray 1x/wk | 4 | Hatching / recovery |
| October | 23-27 C | 18-21 C | 38-41 C | 4 | 11 h 45 m | 9 h 45 m | 50-65 / 60-75% | Light spray 1-2x/wk | 3-4 | Autumn taper |
| November | 21-24 C | 16-19 C | 34-37 C | 3 | 10 h 45 m | 8 h 45 m | 55-70 / 65-80% | Light spray 2x/wk | 3 | Cooling / reduced activity |
| December | 19-22 C | 14-17 C | 30-33 C | 2-3 | 10 h 15 m | 8 h 15 m | 55-70 / 65-80% | Light spray 1-2x/wk | 2-3 | Cool winter rest |
Keeper notes
Use measured gradients and animal behaviour, not single thermostat readings
T5 UVI measurement
Measure UVI at normal back height directly beneath the brightest accessible part of the optional T5 strip. Place the strip toward the middle/back with free access to and away from it; preserve a gradient into fully covered refuges near UVI 0. These numbers describe the exposure area, not the whole enclosure or a daily average.
UVI review
The retained range remains a provisional captive working target. No new species-specific result was found that clearly requires a numerical change. Retaining it is not certification of an experimentally established optimum.
Habitat and climate
Gallotia stehlini is endemic to Gran Canaria and uses rocky volcanic habitats, scrub, agricultural edges and disturbed landscapes. Gran Canaria has mild winters and warm, extremely dry summers; rainfall is concentrated mainly in autumn and winter.
Thermal management
Use a broad gradient rather than a uniformly hot enclosure. Active-season basking surfaces around 40-45 C are appropriate, but shaded retreats must remain much cooler. Winter cooling should be mild, not deep brumation.
Humidity and rain
Summer exposed surfaces should remain dry, reflecting almost rainless June-August conditions, but provide a slightly humid burrow/retreat and constant drinking water. Increase localized spraying modestly in autumn/winter.
Diet
Adults are overwhelmingly herbivorous. A comparative field study found approximately 94-99% vegetal matter by dry weight. Base feeding on leafy greens, weeds, browse, flowers and controlled fruit, with animal prey only as a minor supplement. Juveniles require more invertebrates.
Reproduction
A six-year captive study recorded June-August oviposition, one clutch annually, mean 9.8 eggs with a 5-14 range, and incubation of 75-86 days (mean about 80). Other experienced keepers report larger clutches and occasional second clutches.
Winter conditioning
Successful captive keepers commonly provide about two months of reduced heat and feeding in winter. A practical target is roughly 19-23 C by day and 14-18 C at night with reduced basking.
Nest warning
Provide at least 30-40 cm of warm, diggable soil/sand with a lightly moist lower layer before June. Large females may test-dig repeatedly and require substantial nesting depth.
Social warning
Adult males are large and powerful. Use multiple basking, feeding and refuge sites and separate immediately for sustained aggression or exclusion.