Corucia cold tolerance

My first Solomon's was left loose in a room with a screened window basking area. At night the temperature would sometimes drop to 40F, yet he often chose to sit right by the screen, though there were heated basking and hide areas, and the room was warm. This worried me at first, but I gave up since he would stubbornly return to the spot when he felt like it and felt no ill effects.
More recently I have noticed that my caged colonies will often sit in the cooler part of the cage at night, and when they get loose, will also sit in cold places.
I also recently lost one individual into my yard. I found him a week later none the worse for wear, though one night temps dropped into the 50s. (note that this is the first time one got out - fixed the breach in security and made myself sick in the meanwhile..).
What are the microclimate temperatures that they live in? I wonder if the canopies in the Solomon islands are somehow colder than the tropical conditions would suggest, maybe from wind chill? Anyone know of any studies out there ? Unlike snakes and iguanas, cold spells do not seem to induce respiratory infections in these animals - they just seem to slow down. My Tiliquas also seem that way, but they like it hotter if given a choice.

Hello Phil,

Unfortunately, no direct studies in the upper canopy of the Solomon rainforests has ever been done. De Vosjoli did studies in the nearby New Caledinia rainforests (See refernces below - Vivarium magazine). I have pasted a paper written in this direction that is posted in the Faunaclassifed Scientific Journal Section. My indirect interpretation, this is probably the closest shot in determining the actual temperature at the higher altitude since total deforestation seems immanent. By a blown forecast, I had Corucia in South Florida experience 59 degrees with no deleterious effects. I however, made it a practice with outdoor Corucia to bring them in whenever the temperature dropped below 68 degrees. Even if they could tough it out, the potential stress to their systems is not worth the risk in my opinion.

Enclosed is the article for what it's worth....

Courtesy of POLYPHEMOS:

Natural and simulated climate - Corucia

--------------------------------------------------------------------------------

Leeway Corucia Research Center (LCRC)


Abstract:

Little has been studied in the high canopy of the Solomons regarding climate. Through interpretation from lower areas along the coast an estimate
of natural climate of Corucia was deduced. In addition, simulated conditions in captivity have provided more data concerning climate.


Corucia zebrata is a high-canopy arboreal lizard (Schnirel {POLYPHEMOS -2004}) . In

the Solomon archipelago, there is little seasonal variation in temperature. Rainfall

varies in that there is a dry season from June- August and a wet season from

February to May and from September to November.

Temperature varies in latitude with the average temperature declining about 4

degrees F. per 990 feet change in elevation. Taking this and information from

23 year climate data from Honiara on Guadalcanal which has an elevation of 594

feet, the following can be complied on Corucia temperture at the appropriate

higher elevation. The general range in temperature would be from 68 degrees F. at

night and 84 degrees F. during the day. Extremes compensated for elevation would

be 59 degrees at the absolute minimum and 92 degrees at the maximum. The upper

canopy in the mountains would have a descending airflow at night during semi-prime

Corucia activity. The upper elevations at night have Katabatic winds (also known as

Fall or Bora winds) which descend towards the coast as the lower elevations have an

outward flow of air towards the warmer, nighttime ocean.

Evaporation at prime temperature and humidity with a gentle downward Katabatic

wind would be at 6.17 - 9.33 mm (.24 -.37 inches) in a 24 hr. period. A value greater

than the maximum would cause uncomfort and desiccation to Corucia zebrata. A

consistent lower rate of evaporation from the minimum can lead to parasitic fungal

and bacteria infections. The Moon Condition characterised by crater-like pits

(Schnirel, 2002) Is caused by Pseudomonas bacteria (DuPont, 2002). Since climatic

studies have not been done in the higher terrain of the Solomons; let alone the

upper-canopy, this data is based on research done at the Leeway Corucia Research

Center (LCRC) using a L-2 series evaporimeter with a 30 mm diameter. Conditions

of the upper rainforest canopy in the higher terrain environment of Corucia zebrata

were duplicated as much as possible to the conditions described above. This included

a slight downward Katabatic-like airflow at night. The conditions used would be

optimum and matchable for captive propagation of Corucia zebrata and thus, these

evaporation figures would be of greatest value for non wild Corucia. Due to no

actual studies in the canopies where Corucia zebrata reside, some slight

variation in the above results are possible. Some factors to consider can be

amount of filtered sunlight, % of time the Corucia canopy is in a cloud forest

environment (Quantity of water held in the clouds), height arrangement of the

forest canopy, and velocity / turbulence of the wind. Merriam (1973) studied

the effects of horizontal preciptation (fog drip) using artifical leaves in a fog

wind tunnel. The special distribution of leaves and the properties of their

surface may have to be taken into account for assessment of area evaporation.

This would be especially so during periods of precipitation. Fog drip depends

on total leaf surface as well as whether the leaves possess drip tips.

Assessment of the leaves of the high canopy of the Solomon archipelago

would depend on the ratio of tree leaves and their relative design to leaves

of Pothos and other vines present in the canopy.


Humidity should be 62% at the minimum, with 84-92% an average. Since heavy

rainshowers are common, especially in the wet season, 100% is common and relished

by Corucia which become very active in a downpour. However, as mentioned

above, excessive periods of stagnant humidity at or near 100% is unnatural and

potentially detrimental.

Discussion:


Corucia based on captive observations seem to prefer to drink water in the

following three categories:



1). Being from a rainforest environment, Corucia seem to prefer first to obtain

drinking water directly from natural rain showers which are often frequent in the

Solomons, primarily in the rainy season.


2). Also indicative of a rainforest environment, Corucia will drink water

secondarily from standing leaves- especially those of a drip-tip design (designed

to eliminate excess water by the plant; thereby stopping fungal growth).


3). If pools are available, (In the wild tree top canopy, this would manifest

itself through pools in crouches of trees), Corucia will tertiary drink water from

this method.


References:
de Vosjoli Phillippe; Account from the Daily journals of Phillippe Fast, Frank; 1995. de Vosjoli and Frank Fast. The Vivarium,
Volume 6-Number 5, Escondido, California,
U.S.A. pp 4-7, 12-17, 36-38, 40-44.

McCoy, Michael; Reptiles of the Solomon Islands. Wau Ecology
1980. Institute, Handbook No. 7:30. Papua New
Guinea.


Merriam, R.A. Fog drip from artificial leaves in a fog wind
1973. tunnel. Water Resources Research 9(6) :
1591 - 1596.


Parker, F.; 1983. The prehensile tailed-skink (Corucia zebrata)
on Bougainville Island, Papua New Guinea.
Advances in Herpetology and Evolutionary
Biology, Museum of Comparative
zoology.

Schnirel,
Brian L.; 2004. Seni biometric analysis on the extinct Scincidae
species:Macroscincus coctei (underlined).
Polyphemos, Volume 2, Issue
1, May, Florence, South Carolina, U.S.A. pp. 12-
22. Cambridge, Massachusetts, U.S.A. pp.
435-440.

New Caledonia - Sorry for typo

Thanks for the info. Currently I allow them to stay at room temp at night, which is never much below high 60F, and heat during the day. They seem to prefer a cool down period as they shun heat sources at night. Are yours at ambient temps at night, or do you have basking areas for them ?

Thanks for the info.