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.
