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 12.0 h; T5 UVB 10 h.
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 4-6directly 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
Wettest phase / browse abundance
Curaçao semi-arid dry forest and rocky scrub; prolonged dry season with brief seasonal rains
29-31 CDay ambient
25-26 CNight
38-41 CBasking
4-6T5 UVI*
12.0 hPhotoperiod
10 hT5 UVB duration
68-82 / 82-92%RH day / night*
Frequent short showersRain / mist
7Food days/week
Annual schedule
Scroll sideways on smaller screens
| Month | Day ambient | Night | Basking | T5 UVI* | Photoperiod | T5 UVB duration | RH day / night* | Rain / mist | Food days/week | Seasonal management |
|---|---|---|---|---|---|---|---|---|---|---|
| January | 28-30 C | 23-25 C | 38-41 C | 4-6 | 11.5 h | 9 h 30 m | 60-72 / 72-82% | Occasional AM mist | 6 | Late rains; breeding condition |
| February | 28-30 C | 23-25 C | 38-41 C | 4-6 | 11.8 h | 9 h 48 m | 55-68 / 70-80% | Drying; 2-3 light mists/wk | 6 | Dry season starts; courtship |
| March | 28-31 C | 23-25 C | 39-42 C | 4-6 | 12.1 h | 10 h 6 m | 52-66 / 68-78% | Sparse mist; water always | 5-6 | Main mating period |
| April | 29-31 C | 24-25 C | 39-42 C | 4-6 | 12.4 h | 10 h 24 m | 50-64 / 68-78% | Dry upper zones; moist nest | 5-6 | Mating / nesting begins |
| May | 29-32 C | 24-26 C | 39-42 C | 4-6 | 12.6 h | 10 h 36 m | 50-65 / 68-80% | Very dry air; moist deep nest | 5 | Main oviposition / recovery |
| June | 29-32 C | 24-26 C | 39-42 C | 4-6 | 12.7 h | 10 h 42 m | 52-68 / 70-82% | Dry; occasional pulse rain | 5-6 | Late laying / incubation |
| July | 29-32 C | 25-26 C | 39-42 C | 4-6 | 12.6 h | 10 h 36 m | 55-72 / 72-84% | Transitional; light showers | 6-7 | Incubation / first hatchlings |
| August | 29-32 C | 25-27 C | 39-42 C | 4-6 | 12.4 h | 10 h 24 m | 58-75 / 74-86% | More showers / fresh browse | 7 | Main hatchling emergence |
| September | 30-32 C | 25-27 C | 39-42 C | 4-6 | 12.2 h | 10 h 12 m | 62-78 / 78-88% | Wet-season build-up | 7 | Juvenile growth / recovery |
| October | 29-31 C | 25-26 C | 38-41 C | 4-6 | 12.0 h | 10 h | 68-82 / 82-92% | Frequent short showers | 7 | Wettest phase / browse abundance |
| November | 28-31 C | 24-26 C | 38-41 C | 4-6 | 11.7 h | 9 h 42 m | 68-82 / 82-92% | Frequent showers | 7 | Wet phase / body condition |
| December | 28-30 C | 23-25 C | 38-41 C | 4-6 | 11.5 h | 9 h 30 m | 64-78 / 78-88% | Showers easing | 6-7 | Conditioning toward 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.
Population identity
Use Iguana iguana - Curaçao population. Genetic work treats Curaçao animals as a highly distinctive dry-forest population. Preserve locality and pedigree; do not assign an unsupported subspecies name.
Natural climate
Official Curaçao climate data describe a dry season Feb-Jun, transitional Jul-Aug and rainy season Sep-Jan. Temperatures remain tropical all year and strong trade winds are normal.
Enclosure
Large arboreal enclosure with heavy trunks, wide shelves, shaded retreats and deep nesting substrate. About 200 x 120 x 200 cm is only a practical indoor minimum starting point for one adult; larger is preferable.
Heat and UVB
Use about 28-32 C daytime air, 23-27 C nights and a broad 38-42 C basking surface. A measured UVI around 4-6 at the main basking zone is a practical target, with shaded retreats below UVI 1.
Humidity and rain
Reduce rain/mist during Feb-Jun but never remove drinking water or humid retreats. Increase showers in Jul-Aug and use frequent short rain events Sep-Jan. Maintain strong ventilation.
Diet
Plant-based diet: calcium-rich greens, safe browse, leaves, flowers and fibrous vegetables daily, with smaller fruit portions. Seasonal browse abundance can be increased after summer rains; do not starve animals to mimic drought.
Breeding
Curaçao field studies place courtship and mating in March-April and oviposition mainly late April-May. Hatchlings emerge before the main rainy season, when new leaves become available.
Nesting / incubation
Provide 45-60+ cm of compactable sandy-soil nest substrate. Curaçao females produce fewer but larger eggs than humid-mainland green iguanas; a later comparison reports a mean clutch around 16.9 eggs. For incubation, about 28.5-30 C is a conservative general green-iguana starting range where Curaçao-specific trials are lacking.
Conservation warning
Do not cross locality-known Curaçao animals with unknown-origin or morph iguanas if conserving the island lineage matters. Adult males can be strongly territorial and females need monitoring for nesting difficulty.