Asian Forest Scorpions - Facts

[The Snark]

In Situ, their natural habitat.
1. Loose deep detritus preferred. Commonly 2 to 6 inches deep.
Affords the ability to hide in any location where they hunt.
2. Moisture not required.
It may facilitate molting but is not necessary. From May into November is the rainy months with the detritus normally moist. December on into May their habitat is normally extremely dry.
3. 16 C to 18 C, 60 F to 66 F, is the median temperature of their native habitat derived from the earth below the detritus layer. Thermal battery effect.
They will also use the mediating thermal battery effect during daylight hours when they are hiding such as rocks and rubble which tend retain the median temperature.
4. They never come out of their hides until it is dark.
S.E. Asia is wall to wall predators. Mostly birds, rats and some species of mice, but any prowling animal will make short work of them.
5. Their eyesight in primarily motion detectors.
During daylight, any ambient light, it is inhibited and they may not even detect prey directly in front of them.
6. Starting in August through October is mating season.
Essentially suicide runs for males randomly searching for females. The males can often end up in locations where there are no suitable hides come daylight and fall prey to predators.
7. Starting in November they glut themselves with food.
By the first of the year the forests are bone dry with very little insect activity. In hibernation they can go about 4-5 months without food.

This table is mean average air temperature. The soil temperature varies considerably less and rarely goes above 15 C - 60F. Note that at night when they are normally active the average yearly air temperature is 20 C - 68 F.

Month	Min (°C)	Max (°C)	Mean (°C)	Min (°F)	Max (°F)	Mean (°F)
January	14	29	21.5	57	84	70.7
February	16	32	24	61	90	75.2
March	19	35	27	66	95	80.6
April	22	36	29	72	97	84.2
May	24	34	29	75	93	84.2
June	24	33	28.5	75	91	83.3
July	24	32	28	75	90	82.4
August	24	31	27.5	75	88	81.5
September	23	32	27.5	73	90	81.5
October	22	31	26.5	72	88	79.7
November	19	30	24.5	66	86	76.1
December	15	28	21.5	59	82	70.7
Year	20.5	31.9	26.15	68.9	89.4	79

 

[Edan bandoot]

What's your local sp that you're referring to?

 

[The Snark]

What's your local sp that you're referring to?

H. laoticus, H. spinifer, H. longimanus, H. cyaneus, H. fulvipes and H silenus
Northern Thailand, N.E. Burma, and Western Laos is roughly the center of four species and occasional reports of the other two being present. I will have to check which are the most common here.
The full geographical extent of the "Asian Forest Scorpion" as listed above is Cambodia, Laos, Thailand, Vietnam, India, Sri Lanka, Bangladesh, Nepal, and China
H bengalensis, H gravimanus, H indus, H kanarensis, and H swammerdami are not considered 'Forest' scorpions.

 

[KenEnd]

Thank you for the helpful insight Snark <3 Much appreciated.

 

[Albireo Wulfbooper]

This table is mean average air temperature. The soil temperature varies considerably less and rarely goes above 15 C - 60F. Note that at night when they are normally active the average yearly air temperature is 20 C - 68 F.

I was wondering about soil temperature a while back but had some trouble finding data on this. Of course the soil has a strong insulating effect that will buffer temperature, but it's good to have some sense of what that buffer range is. Do you know at what depth the soil temperature would have been measured for this? Obviously there will be more variation in the very top layer, even in shaded forest soils, but I'm curious how far down you have to dig to have very stable temperatures in that context. I assume that in the context of an enclosure where the soil volume is necessarily less, the buffer will be somewhat less effective. I'm tempted to get a dedicated soil thermometer to monitor substrate temperature in my scorpion enclosures as the house temperature fluctuates throughout the year (my room ranges from ~20ºC to ~33ºC seasonally), just for the sake of curiosity

 

[wizentrop]

@Albireo Wulfbooper, gotta make them thrive

Seriously, this is a great collection of info @The Snark! People often overlook seasonal variation, ground level (or below) temperatures, photoperiod, and even simple things like prey variation. This is good stuff that gives the bigger picture.

 

[The Snark]

I was wondering about soil temperature a while back but had some trouble finding data on this. Of course the soil has a strong insulating effect that will buffer temperature, but it's good to have some sense of what that buffer range is. Do you know at what depth the soil temperature would have been measured for this? Obviously there will be more variation in the very top layer, even in shaded forest soils, but I'm curious how far down you have to dig to have very stable temperatures in that context.

When one part of a couple, close friends of mine, abandoned his partner she gave me his soil science textbooks, around 1984. They became loose leaf, got moldy and I finally tossed them around 2010-12.
The short answer. Soil temperature at the surface can be roughly gauged by how verdant the native plant growth is. Ideal as found in tropical rain forests is 18-24 C or 64-75 F. The ideal being best for germination and establishment of the widest variety of species of plants.
The long answer is found here and a couple of years of college bio-science is highly recommended. https://geothermal-energy-journal.springeropen.com/articles/10.1186/s40517-017-0082-z

Another rough rule is the thermocline data of soils is a small fraction of open air and is dependent upon soil moisture. VERY roughly soil temperature transference is measured in inches where open air is measured in hundreds of feet. (An extreme example being the cumulus cloud development on the west coast of equatorial Africa where moist air near the earth surface can move up to 40,000 feet in a period of a few hours).
Or putting it in simplified terms, soil temperatures don't vary much, year round.

Or to sum up, Asian forests where these scorpions thrive is high temperate to the lower side of tropical temperatures, averaging 20 C or 68 F. year round. During their hibernation period the temperatures are the highest with their habitat being over half deciduous forests which shed their leaves and allow more sunlight to reach the ground. During the rainy season when they are most active the ground is much moister with little or no sunlight which allows the subsurface cooler temperatures to slowly rise to the surface.

but I'm curious how far down you have to dig to have very stable temperatures in that context.

Median temperature derivation data commonly used is one meter below the soil surface

Of course the soil has a strong insulating effect that will buffer temperature,

Lots of data on the 'thermal battery (retention) effect'. Web search earth ship design.

Another excellent source of info: https://www.epa.gov/climate-indicators/climate-change-indicators-permafrost

PS Plant variety is directly related to ideal soil temperature. Compare the boreal forests (often a single species for acres) to the tropical. where dozens or even over 100 different species compete.

 

[The Snark]

-By the way, the environment where that animal is sedentary in the wild should always be taken into account with terrariums. Rough tolerance tables can be worked out accordingly.
Examples: Birds mostly are adapted to the air temperature. Many sparassids and similar ranging hunters are adapted to the local air temperature and lowering the temperature helps trigger them to become active. Scorpions and other detritus dwellers operate from soil surface temperatures and hole dwellers as moles and gophers are active year round day and night as they dwell in the near thermally stable sub soils.