Chapter Index

Light, temperature, humidity for captive lorises and pottos

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For natural climatic conditions in the habitats of different forms See our databas page at  http://www.loris-conservation.org/database/population_database/tables/13-Ecology.pdf
See also chapters "Temperature Levels" and "Lighting Conditions" in Fitch-Snyder et al 2001: Management of Lorises in Captivity - A Husbandry Manual for Asian Lorisines (Nycticebus & Loris ssp.)

Health problems due to lack of natural sunlight are not known (our lorises regulary get vitamins with the food).
Flickering of defect neon tubes may cause epileptoform seizures in Loris. Such flickering can be prevented by using starters which switch off the tube completely when it is defect.
The normal flickering frequency of neon tubes ought to be considered, Michael Günther (pers. comm.) said lorises and galagos probably see the flickering frequency. There is a technical device which can be built in to prevent neon tubes from flickering, I am not sure about its English term (Ballast? Control gear?)
Light colour: red light is said to be less visible for lorises and may therefore be advantageous for observation unless infrared night vision equipment is available. Blue light looks moonlight-like on exhibition. Dim normal, yellowish light, however, seems well suitable,

Table: signs of inadequate climate or light in slender lorises

Temperature Humidity of the air Light intensity during animal night
Recommended value See our page about  Ecology for needs of the different taxa. 
In our colony, in cooler cages and in cages for very old animals heated sleeping places are provided. 
More than 65% Activity is apparently influenced by a combination of zeitgebers and actual light intensity. About one or two lux or more, activity in the "animal evening" started when light was dimmed below about 6 lux. But animals can be habituated to some degree to rather bright night light. At Ruhr-University, light is dimmed after observation of behaviour (see below) and occasionally human needs for behavioural observation
Signs for (too) high values Relaxed, energy-saving resting postures, animals sleeping with their face visible and sometimes with the legs hanging sideways, not tightly rolled up. The veins in the auricles may be enlarged, in males the testes may be scrotal and enlarged, particularly during sleeping period, probably for better emission of heat. In cages not regularly cleaned, ammonia may develop in the urine layer on the branches, causing skin problems in the parts of the trunk in contact with the btanch during sitting. Respiratory problems by ammonia vapours? 7 - 18 lux were tolerated by captive L. l. nordicus, most animals in a test showed activity. Possible consequences of too bright light: increased shyness and absence of certain behaviour only shown when the animals feel undisturbed.
Considerably too bright light: animals initially stayed in sleeping posture during activity time, with only some food intake, then returning to the sleeping place. With longer duration some activity was aobserved (observed in captive L. l. nordicus at about 40 - 50 lux in unsystematic tests)
Signs for (too) low values Increased food consumption. 
In one zoo, 16°C were tolerated by healthy L. l. nordicus. This, however, is a temperature rarely observed in their natural habitat; especially slender lorises from warmer lowland regions with their scarcely haired long limbs certainly are not adapted to low temperatures.
In some N. pygmaeus, torpor was observed when cooled down, animals became active again after re-warming, but some caught a cold. The animals apparently did not avoid too cold places like concrete floors. 
Repeated sneezing In old animals, vision may decrease. Under dim light conditions (less than 1 lux); attempts to leave such dark cages and move to lighter areas were observed

How to measure light intensity with a camera exposure meter:
18 DIN, exposure time 1/30 Sec.; Diaphragm:
2:  500 Lux
2,8: 1000 Lux
4:  2000 Lux
5,6-8: 5000 Lux
8-11: 10000 Lux
11-16: 20000 Lux
22:  50000 Lux


Charles-Dominique, P., 1977: Ecology and Behavior of Nocturnal Primates. New York: Columbia University Press.
Conway, K. M.; Shaw, L. J.; Micklesen, S.; Crouse, D. W., 1978: Activity rhythms of ten species of nocturnal animals as a function of light intensity. Pp. 101-140 in: Crockett, C.; Hutchins, M. (eds.): Applied behavioral research at the Woodland Park Zoological Gardens, Seattle, Washington 1977. Pika Press, Seattle.
Erkert, H. G., 1989: Lighting requirements of nocturnal primates in captivity: a chronobiological approach. Zoo Biol. 8 (2): 179-191.
Frederick, C.; Fernandes, D., 1994: Increased activity in a nocturnal primate through lighting manipulation: The case of Perodicticus potto. International Zoo Yearbook 33: 219-228.
Frederick, Ch.; Fernandes, D.; Pastorello, L., 1995: Photoperiod and activity profiles of captive nocturnal prosimians. Laboratory Primate Newsletter 34 (3): 4-6. Online edition: http://www.brown.edu/Research/Primate/lpn34-3.html#photo
Fitch-Snyder, H.; Schulze, H.; Larson, L. et al., 2001: Management of Lorises in captivity. A husbandry manual for Asian Lorisines (Nycticebus & Loris spp.). Center for Reproduction of Endangered Species, Zoological Society of San Diego, Box 551, San Diego, CA 92112-0551. Online edition
Harker, J. E., 1964: The Physiology of Diurnal Rhythms. Cambridge: Cambridge University Press.
Kavanau, J. L.; Havenhill, R. M., 1976: Compulsory regime and control of environment in animal behaviour. III. Light level preference of small nocturnal mammals. Behaviour 59: 203-225.
Nash, L. T., 1986: Influence of moonlight level on traveling and calling patterns in two sympatric species of Galago in Kenya. Pp. 357-367 in: Taub, D. M.; King, F. A. (eds.): Current perspectives in primate social dynamics. Van Nostrand Reinhold Co., New York.
Pariente, G. F., 1979: The role of vision in prosimian behavior. Pp. 411-459 in: G. A. Doyle & R. D. Martin (Eds.): The Study of Prosimian Behavior. Academic Press, New York.
Petter-Rousseaux, A., 1980: Seasonal activity rhythms, reproduction and body weight variations in five sympatric nocturnal prosimians in simulated light and climatic conditions. Pp. 137-152 in: Nocturnal malagasy primates. Ecology, physiology and behavior, Charles-Dominique, P.; Cooper, H. M.; Hladik, A.; Hladik, C. M.; Pages, E.; Pariente, G. F.; Petter-Rousseaux, A.; Schilling, A. (eds.),. Academic Press, New York. UB Bochum: VXB 4438
Keywords: Microcebus; Mirza; Cheirogaleus; Phaner; Lepilemur; circadian rhythms; reproduction; locomotion
Redman, J. F., 1979: Effect of light on the circadian rhythm of the slow loris, Nycticebus coucang. Thesis, Stockton (CA), University of the Pacific.
Trent, B. K.; Tucker, M. E.; Lockhard, J. S., 1977: Activity changes with illumination in slow loris, Nycticebus coucang. Applied Animal Ethology 3: 281-286.
Ward et al. 1970: Psychon. Sci. 18: 265-266: information about perception of neon light - flickering frequency? Not yet checked
Ward et al. 1970: J. Comp. Physiol. Psychol. 73: 74-77.: information about perception of neon light - flickering frequency?
Ward, Doerflein 1971: Psychon. Sci. 23: 43-45.: information about perception of neon light - flickering frequency?
Yoda, K., 1974: Three-dimensional distribution of light intensity in a tropical rain forest of West Malaysia. Jap. J. Ecol. 24: 247-254.

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Conservation database for lorises (Loris, Nycticebus) and pottos (Arctocebus, Perodicticus), prosimian primates
Slender loris husbandry information, H. Schulze, Ruhr-University Bochum
Last amendment: 19 May 2008
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