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 11.6 h; T5 UVB 9 h 36 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 4-6directly under the tube when it is on
Replace the blanket UVI 5-7 default with an optional adult T5 patch at UVI 4-6, aiming initially around 5. This is a moderate working choice within published exposure guidance, not proof that 5-7 is harmful or a measured optimum for every Cyclura. Published UV-Tool assignments vary even within the genus; no trial was found that makes UVI 7 a necessary default.
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: Inferred genus-level working range. 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
Hatchlings / recovery; dry exposed surfaces
Cuba and offshore cays - dry tropical forest, xeric coastal scrub, limestone and sandy nesting areas
28-31 CDay air
23-25 CNight
43-47 CBasking
4-6T5 UVI*
11.6 hPhotoperiod
9 h 36 mT5 UVB duration
64-80 / 78-90%RH day / night*
Wet / storm season easingRain / mist
6Food days/week
Annual schedule
Scroll sideways on smaller screens
| Month | Day air | Night | Basking | T5 UVI* | Photoperiod | T5 UVB duration | RH day / night* | Rain / mist | Food days/week | Seasonal management |
|---|---|---|---|---|---|---|---|---|---|---|
| January | 25-28 C | 19-22 C | 42-46 C | 4-6 | 11.0 h | 9 h | 50-65 / 65-80% | Dry maintenance; light AM mist 2-3x/wk | 5 | Cooler drier phase; maintain lean adults |
| February | 25-28 C | 19-22 C | 42-46 C | 4-6 | 11.5 h | 9 h 30 m | 50-65 / 65-80% | Dry; localized moist refuge | 5 | Dry-season conditioning; varied browse |
| March | 26-29 C | 20-23 C | 42-47 C | 4-6 | 12.0 h | 10 h | 52-68 / 68-82% | Dry; exposed surfaces fully dry | 5-6 | Seasonal warm-up; no brumation |
| April | 27-30 C | 21-24 C | 43-48 C | 4-6 | 12.7 h | 10 h 42 m | 55-70 / 70-84% | Dry-to-wet transition | 5-6 | Increase food quality; nest zone ready |
| May | 28-31 C | 23-25 C | 44-48 C | 4-6 | 13.2 h | 11 h 12 m | 60-75 / 74-87% | Wet-season onset; regular rain pulses | 6 | Primary courtship / mating; monitor aggression |
| June | 29-32 C | 24-26 C | 44-48 C | 4-6 | 13.5 h | 11 h 30 m | 64-80 / 78-90% | Wet; regular rain pulses | 6-7 | Primary oviposition; inspect nest area daily |
| July | 29-32 C | 24-26 C | 44-48 C | 4-6 | 13.4 h | 11 h 24 m | 62-78 / 76-89% | Warm wet phase; possible rain lull | 6-7 | Incubation / female recovery |
| August | 29-32 C | 24-26 C | 44-48 C | 4-6 | 12.9 h | 10 h 54 m | 62-80 / 78-90% | Warm wet / storm phase | 6-7 | Incubation; expected hatch window begins |
| September | 29-32 C | 24-26 C | 43-48 C | 4-6 | 12.2 h | 10 h 12 m | 66-82 / 80-92% | Wet / storm peak; strong ventilation | 6-7 | Hatching / emergence; juvenile growth |
| October | 28-31 C | 23-25 C | 43-47 C | 4-6 | 11.6 h | 9 h 36 m | 64-80 / 78-90% | Wet / storm season easing | 6 | Hatchlings / recovery; dry exposed surfaces |
| November | 27-30 C | 22-24 C | 42-46 C | 4-6 | 11.1 h | 9 h 6 m | 58-72 / 72-85% | Rain reduces | 5-6 | Transition toward dry season |
| December | 26-29 C | 20-23 C | 42-46 C | 4-6 | 10.8 h | 8 h 48 m | 52-68 / 68-82% | Drier phase; light AM mist | 5 | Seasonal reset; reduce rain, not water |
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
Replace the blanket UVI 5-7 default with an optional adult T5 patch at UVI 4-6, aiming initially around 5. This is a moderate working choice within published exposure guidance, not proof that 5-7 is harmful or a measured optimum for every Cyclura. Published UV-Tool assignments vary even within the genus; no trial was found that makes UVI 7 a necessary default.
Taxonomy and range
Written for the nominate Cuban taxon Cyclura nubila nubila, native to Cuba and offshore cays. Do not apply unchanged to the Sister Isles Rock Iguana, C. n. caymanensis.
Heat and UVB
Use a broad 42-48 C basking-surface working target and UVI 4-6 at the principal basking zone, with cooler air and immediate deep shade. These are operational targets, not experimentally proven thresholds.
Diet
Primarily herbivorous. Prioritize calcium-rich browse, leafy weeds, flowers, fibrous vegetables and cactus. Wild crabs or carrion are opportunistic and do not justify routine high-protein feeding.
Breeding
The IUCN husbandry manual reports mating mainly in May and oviposition in June. Guanahacabibes field observations also documented active nesting in late May and June.
Nesting
Nests occur in soil or sand, often under rocks or plants. Isla Magueyes tunnels averaged about 153 cm with one or two turns and chambers about 43 cm deep. Provide at least 60-80 cm of compactable substrate plus broad tunnelling space.
Clutch and incubation
Up to 30 eggs are reported, averaging about 8.6. For Isla Magueyes, 31-32 C and approximately 70-78 days are the strongest published incubation starting values.
Status
The IUCN SSC Iguana Specialist Group lists the Cuban Rock Iguana as Vulnerable; Cyclura nubila is CITES Appendix I.
Locality caution
Cuba has substantial geographic climate variation. Exact locality and established lineage records override this generic wet-dry calendar.