Keeper timer setting
T5 UVB: one hour later on, one hour earlier off
ON: 1 hour after the daylight lights come on.
OFF: 1 hour before the daylight lights go off.
October: daylight 11 h 45 m; T5 UVB 9 h 45 m per day.
The T5 runs for two hours less than the total photoperiod. Example: daylight 08:00-20:00 means UVB 09:00-19:00. Keep the monthly UVI strength as listed beneath the tube. Existing care values are preserved.
UVI beneath the optional T5 tube
Working exposure targetOctober target at normal back height
UVI 3-4directly 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 ยท Muryn, Baines and Dishman (2026), Reptile Lighting Guide V10
October management
Selected automatically using the Netherlands date
Rains taper
Tropical dry forest, rocky slopes, open woodland and agricultural mosaics - western and central Mexico
26-29 CDay ambient
20-22 CNight
41-43 CBasking
3-4T5 UVI*
11 h 45 mPhotoperiod
9 h 45 mT5 UVB duration
45-60 / 60-75%RH day / night*
2-3 light rain events/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 | 25-28 C | 18-21 C | 41-43 C | 3-4 | 11 h 15 m | 9 h 15 m | 35-50 / 50-65% | Light local spray 1-2x/wk | 4-5 | Vitellogenesis / mating begins |
| February | 26-29 C | 18-21 C | 42-44 C | 4 | 11 h 40 m | 9 h 40 m | 35-50 / 50-65% | Light local spray 1-2x/wk | 4-5 | Peak mating |
| March | 28-31 C | 19-22 C | 43-45 C | 4-5 | 12 h 05 m | 10 h 5 m | 30-45 / 45-60% | Minimal; drinking water available | 4-5 | Gravid; nesting prep |
| April | 29-32 C | 20-23 C | 43-45 C | 4-5 | 12 h 35 m | 10 h 35 m | 30-45 / 45-60% | Minimal + moist lay chamber | 4-5 | Main oviposition window |
| May | 29-32 C | 21-24 C | 43-45 C | 4-5 | 13 h | 11 h | 45-60 / 60-75% | 2-3 light rain events/wk | 4-5 | Early rainy season / incubation |
| June | 28-31 C | 21-24 C | 42-44 C | 4 | 13 h 15 m | 11 h 15 m | 55-70 / 70-85% | 3-4 rain/mist events/wk | 4-5 | Hatching begins |
| July | 27-30 C | 21-24 C | 42-44 C | 4 | 13 h | 11 h | 55-70 / 70-85% | 3-5 rain/mist events/wk | 4-5 | Hatchlings / wet-season feeding |
| August | 27-30 C | 21-24 C | 42-44 C | 4 | 12 h 40 m | 10 h 40 m | 55-70 / 70-85% | 3-5 rain/mist events/wk | 4-5 | Peak wet-season activity |
| September | 27-30 C | 20-23 C | 41-43 C | 3-4 | 12 h 10 m | 10 h 10 m | 50-65 / 65-80% | 3-4 rain/mist events/wk | 4-5 | Wet-season maintenance |
| October | 26-29 C | 20-22 C | 41-43 C | 3-4 | 11 h 45 m | 9 h 45 m | 45-60 / 60-75% | 2-3 light rain events/wk | 3-4 | Rains taper |
| November | 25-28 C | 18-21 C | 40-42 C | 3 | 11 h 20 m | 9 h 20 m | 40-55 / 55-70% | Light local spray 1-2x/wk | 3-4 | Dry-season conditioning |
| December | 24-27 C | 17-20 C | 39-42 C | 3 | 11 h 05 m | 9 h 5 m | 35-50 / 50-65% | Light local spray 1-2x/wk | 3-4 | Conditioning / pre-breeding |
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.
Identity and habitat
Ctenosaura pectinata is a large diurnal iguanid native to western and central Mexico. It occupies tropical dry forest, rocky slopes, open woodland and disturbed agricultural mosaics, and uses both terrestrial and arboreal refuges.
Seasonal climate
Central-Mexico populations experience a long dry season from roughly October-May and a summer rainy season. January-April are especially dry; April-May are among the hottest months. Breeding is tied to this dry-season phase.
Thermal management
Provide intense local basking in the low-mid 40s C only if animals can retreat immediately to substantially cooler air and shade. A cool zone around 25-28 C during the day is important; do not maintain the entire enclosure above 30 C.
Humidity and rain
Dry-season RH should be moderate-low with limited local spraying. From May through September, increase short rain/mist events and overnight humidity while maintaining strong ventilation. Exposed surfaces should dry between events.
Diet
Diet changes strongly with age. Small juveniles can eat mostly insects; adults are predominantly herbivorous and should receive varied leafy greens, edible weeds, flowers and browse with only limited animal prey.
Reproduction
Mating/vitellogenesis are best documented in January-February, gravid females are common in April, and mean clutch size in one central-Mexico study was 31.1 eggs (range 12-52). Recent work estimates incubation at about 67-88 days, mean roughly 78.5 days.
Social warning
Males are strongly territorial during breeding. Multiple adult males should not be housed together. Separate any animal for persistent pursuit, biting, refuge exclusion, suppressed feeding or declining body condition.