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
Expected hatching/emergence from July clutches
San Salvador, The Bahamas - coastal scrub, limestone cays and sandy nesting pockets
28-30 CDay air
23-25 CNight
42-46 CBasking
4-6T5 UVI*
11.6 hPhotoperiod
9 h 36 mT5 UVB duration
64-80 / 78-90%RH day / night*
Wettest/storm phaseRain / 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 | 25-27 C | 20-22 C | 41-45 C | 4-6 | 10.8 h | 8 h 48 m | 55-68 / 70-82% | Drier; light AM mist 2-3x/wk | 5 | Cooler dry-season maintenance; keep adults lean |
| February | 25-27 C | 20-22 C | 41-45 C | 4-6 | 11.3 h | 9 h 18 m | 54-67 / 70-82% | Drier; light mist | 5 | Dry-season conditioning; maximize browse variety |
| March | 26-28 C | 21-23 C | 42-46 C | 4-6 | 12.0 h | 10 h | 54-68 / 70-82% | Driest phase; localized refuge moisture | 5 | Seasonal warm-up; no brumation |
| April | 27-29 C | 22-24 C | 42-46 C | 4-6 | 12.7 h | 10 h 42 m | 56-70 / 72-84% | Dry-to-wet transition | 5-6 | Increase feeding quality; prepare nesting substrate |
| May | 28-30 C | 23-25 C | 43-47 C | 4-6 | 13.2 h | 11 h 12 m | 60-74 / 74-86% | Increase rain pulses | 6 | Primary courtship/mating begins |
| June | 29-31 C | 24-26 C | 43-47 C | 4-6 | 13.5 h | 11 h 30 m | 62-76 / 76-88% | Warm; regular rain pulses | 6-7 | Peak mating; gravid females need privacy |
| July | 29-31 C | 24-26 C | 43-47 C | 4-6 | 13.3 h | 11 h 18 m | 60-75 / 75-87% | Warm; moderate rain | 6-7 | Primary oviposition month; inspect nest zone daily |
| August | 29-31 C | 24-26 C | 43-47 C | 4-6 | 12.9 h | 10 h 54 m | 60-76 / 75-88% | Warm; intermittent rain | 6 | Incubation / female recovery |
| September | 29-31 C | 24-26 C | 42-46 C | 4-6 | 12.2 h | 10 h 12 m | 62-78 / 76-90% | Wet/storm season increases | 6 | Late incubation; stable moisture, avoid overheating |
| October | 28-30 C | 23-25 C | 42-46 C | 4-6 | 11.6 h | 9 h 36 m | 64-80 / 78-90% | Wettest/storm phase | 6 | Expected hatching/emergence from July clutches |
| November | 27-29 C | 22-24 C | 41-45 C | 4-6 | 11.1 h | 9 h 6 m | 60-74 / 74-86% | Rainfall easing | 5-6 | Juvenile growth; transition toward dry phase |
| December | 26-28 C | 21-23 C | 41-45 C | 4-6 | 10.7 h | 8 h 42 m | 56-70 / 72-84% | Drier transition | 5 | Seasonal reset; reduce rain, not drinking 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.
Habitat
Restricted to San Salvador and satellite cays in The Bahamas; exposed maritime scrub and limestone with sandy pockets used for nesting.
Heat and UVB
Use a broad 41-47 C basking-surface working target and UVI 4-6 at the main basking area, with cooler air and immediate deep shade.
Diet
Strongly plant-dominant. Field work records coastal plants including Borrichia arborescens, Rhachicallis americana and Opuntia stricta; animal matter is only occasional.
Breeding
Mating occurs mainly in May-June. Green Cay field work found nesting concentrated in July, with larger females tending to oviposit earlier.
Nesting
Natural sandy-soil burrows are about 30-116 cm long with egg chambers 18-28 cm below the surface. Provide deep compactable sand/soil and privacy.
Clutch
Up to 6 eggs are reported, averaging 4.4. Natural incubation lasts approximately 91-92 days.
Incubation caution
A species-specific incubation temperature has not been established. Any artificial temperature range should be treated as an extrapolation from related Cyclura.
Status
Cyclura rileyi rileyi is listed as Critically Endangered by the IUCN SSC Iguana Specialist Group; Cyclura rileyi is CITES Appendix I.