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
Seasonally dry tropical forest, thorn scrub, columnar cactus and tree cavities - Motagua Valley, Guatemala
26-29 CDay ambient
20-22 CNight
40-42 CBasking
3-4T5 UVI*
11 h 45 mPhotoperiod
9 h 45 mT5 UVB duration
55-70 / 70-85%RH day / night*
2-3 rain/mist 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 | 25-29 C | 18-21 C | 40-42 C | 3-4 | 11 h 20 m | 9 h 20 m | 45-60 / 55-70% | Light local spray 1-2x/wk | 4 | Courtship / mating |
| February | 26-30 C | 19-22 C | 41-43 C | 4 | 11 h 40 m | 9 h 40 m | 45-60 / 55-70% | Light local spray 1-2x/wk | 4 | Mating / females gravid |
| March | 28-32 C | 20-23 C | 42-44 C | 4-5 | 12 h | 10 h | 40-55 / 50-65% | Minimal; water always | 4-5 | Gravid / nest preparation |
| April | 29-33 C | 21-24 C | 42-44 C | 4-5 | 12 h 25 m | 10 h 25 m | 40-55 / 50-65% | Minimal + moist lay chamber | 4-5 | Main oviposition window |
| May | 29-32 C | 21-24 C | 42-44 C | 4 | 12 h 45 m | 10 h 45 m | 55-70 / 70-85% | 2-3 rain/mist events/wk | 4-5 | Hatching late month / rains begin |
| June | 28-31 C | 21-24 C | 41-43 C | 4 | 13 h | 11 h | 60-75 / 75-90% | 3-5 rain/mist events/wk | 4-5 | Wet-season activity |
| July | 28-31 C | 21-24 C | 41-43 C | 4 | 12 h 55 m | 10 h 55 m | 60-75 / 75-90% | 3-5 rain/mist events/wk | 4-5 | Peak wet-season feeding |
| August | 28-31 C | 21-24 C | 41-43 C | 4 | 12 h 35 m | 10 h 35 m | 60-75 / 75-90% | 3-5 rain/mist events/wk | 4-5 | Wet-season maintenance |
| September | 27-30 C | 20-23 C | 40-42 C | 3-4 | 12 h 10 m | 10 h 10 m | 60-75 / 75-90% | 3-5 rain/mist events/wk | 4-5 | Late wet season |
| October | 26-29 C | 20-22 C | 40-42 C | 3-4 | 11 h 45 m | 9 h 45 m | 55-70 / 70-85% | 2-3 rain/mist events/wk | 3-4 | Rains taper |
| November | 25-28 C | 18-21 C | 39-41 C | 3 | 11 h 25 m | 9 h 25 m | 50-65 / 60-75% | Light local spray 1-2x/wk | 3-4 | Dry-season conditioning |
| December | 24-28 C | 18-20 C | 39-41 C | 3 | 11 h 15 m | 9 h 15 m | 45-60 / 55-70% | Light local spray 1-2x/wk | 3-4 | Pre-breeding conditioning |
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 palearis is endemic to the Motagua Valley of southeastern Guatemala. It is strongly associated with seasonally dry forest, thorn scrub, columnar cactus and tree cavities, and is primarily arboreal in habitat use.
Seasonal climate
The Motagua Valley dry season is mainly November-April and the wet season May-October. Regional climate is hot and semi-arid, but mean atmospheric RH remains moderate; reproduce rainfall seasonality rather than keeping the enclosure uniformly dry or uniformly humid.
Humidity and rain
During the dry season use moderate RH, strong ventilation and only localized light spraying. From May-October increase short rain/mist events and overnight RH. Exposed branches, bark and rock should dry between events; refuge interiors should not remain stagnant or wet.
Diet
Adult field feces contained both insect and plant material: approximately 47.8% insects, 26.9% leaves, 15.4% flowers and 7.7% fruits in one study. Ants and crickets were common. Use a genuinely mixed diet rather than treating adults as strictly herbivorous.
Reproduction
Females have an annual cycle. Copulation occurs January-February, gravid females February-March, and 6-12 eggs are laid from late March to late April in sandy tunnels. Hatchlings appear around late May as the rains begin.
Social warning
Males become territorial during courtship. House adult males separately and supervise breeding introductions. Separate for biting, repeated pursuit, refuge exclusion, suppressed feeding or declining body condition.