Pangolin Thermoregulation: Sun Basking and Body Temperature
On a warm morning in the South African bushveld, a ground pangolin emerges from its burrow entrance, unfolds from its defensive ball, and stands with its broad, scaled back angled directly toward the sun. It remains almost motionless for several minutes, scales slightly raised, skin and underlying tissue absorbing solar radiation. This is basking — a thermoregulatory behaviour more associated with reptiles than mammals — and in pangolins it reveals an unusual compromise in the warm-blooded mammalian body plan.
Understanding pangolin thermoregulation is essential both for conservation biology and for the captive management of rescued animals. Unlike most mammals, pangolins sit at the edge of effective endothermy: they are warm-blooded but only marginally so, and their temperature control system can be overwhelmed by cold weather, physical stress, or the shock of captivity. Getting thermoregulation right is often the difference between a rescued pangolin surviving rehabilitation or dying within 48 hours of rescue.
Baseline Body Temperature: Cooler Than Most Mammals
The normal core body temperature of a resting ground pangolin (Smutsia temminckii) ranges from approximately 33 to 36 degrees Celsius — significantly lower than most mammals of similar body mass, which typically maintain temperatures of 36 to 39 degrees. This lower baseline is associated with a metabolic rate that is reduced relative to body size predictions: pangolins burn less energy per kilogram than most comparably sized carnivores or omnivores, which matches their sedentary daytime behaviour and their reliance on a high-volume but low-handling-cost prey (termites and ants do not require complex pursuit or killing strategies).
Pangolin Body Temperature at a Glance
Resting core temp: 33–36 °C • Active foraging temp: 35–38 °C • Post-basking peak: up to 38.5 °C • Critical low (hypothermia risk): below 30 °C • Critical high (hyperthermia risk): above 40 °C
The relatively low baseline metabolic rate has implications for cold tolerance. A pangolin exposed to overnight temperatures below 10 degrees Celsius — not uncommon in the Highveld of South Africa in June and July — faces a significant thermoregulatory challenge. Unlike many mammals that can simply increase their metabolic heat production to compensate, pangolins have limited capacity to do so for extended periods. Their primary defence against cold is behavioural: retreating into a well-insulated burrow and adopting a tightly curled posture that minimises exposed surface area.
The Basking Behaviour: Function and Mechanics
Pangolin basking has been documented across African species in both wild settings and at captive facilities. Camera trap recordings at Tswalu Kalahari Reserve and telemetry data from ground pangolins in Limpopo show that basking most commonly occurs in the late morning after the pangolin has exited its overnight burrow, and occasionally in the late afternoon before a nocturnal foraging trip.
During basking the pangolin positions itself to maximise solar exposure of the dorsal (upper) surface — the most heavily scaled area of the body. The scales, which are dark brown to olive in colour, absorb solar radiation effectively, and the underlying skin — relatively thin and vascularised compared with the scale-covered surface — transfers this heat into the bloodstream. The animal may slowly rotate its body as the sun moves, maintaining optimal orientation.
Why Scales Help (and Hinder) Heating
The pangolin's scale armour presents an interesting thermoregulatory paradox. On one hand, the scales are good solar absorbers: dark keratin surfaces readily convert incoming shortwave radiation to heat. On the other hand, the scale layer adds thermal mass and reduces direct skin-to-air contact, slowing both heating and cooling. The slightly raised scale posture observed during basking — where the trailing edges of the scales are lifted slightly away from the body — may increase convective airflow beneath the scales, allowing heat to reach the underlying skin more efficiently.
Researchers have suggested that the scale-lifting behaviour during basking, sometimes described as pangolins "fluffing up" their armour, may serve the dual purpose of thermoregulation and ectoparasite dislodgement. Ticks and mites sheltering between scales would be exposed to desiccating heat and potentially to preening action from the animal's tongue.
Burrow Microclimate: The Primary Thermal Buffer
For ground pangolins, the burrow is the most important thermoregulatory tool. Underground temperatures at depths of one to two metres remain remarkably stable across the seasons in Southern Africa — typically between 18 and 24 degrees Celsius in the high-lying grasslands and bushveld where ground pangolins are most common. This stable microclimate provides a warm refuge on cold winter nights and a cool retreat on hot summer afternoons.
Radio-tracking studies in North West Province and the Kruger National Park have shown that pangolins retreat to deeper burrow sections during cold weather, spending more time in the chamber portion of the burrow rather than the entrance tunnel. Burrow depth selection appears to be actively responsive to surface temperature: the same individual may use shallow burrows in summer and consistently deeper burrows in winter.
Curling as Insulation
When inactive in the burrow, pangolins adopt a tightly curled posture with the tail wrapped over the face and underside. This ball configuration reduces the surface-area-to-volume ratio — the same physical principle that makes a sphere lose heat more slowly than a flat sheet of the same mass. In a closed ball, a pangolin exposes primarily its scaled dorsal surface to the burrow air, while the less-insulated ventral skin and face are tucked inward and warmed by metabolic heat rather than lost to convection.
When pangolins curl in response to a threat — which predators and humans experience as a defensive behaviour — the thermoregulatory value is incidental. But in the cool of a burrow on a July night in Gauteng, the ball posture serves both defence (against any predator that investigates) and heat conservation.
Seasonal Variation in Activity
Ground pangolins in South Africa are less active in winter (June–August) than in summer. This is not hibernation — pangolins do not enter a torpid state with depressed body temperature and suspended metabolism as true hibernators do — but it is a significant reduction in foraging activity. Animals tracked in Limpopo have been recorded spending up to 22 hours per day underground during cold mid-winter periods, compared with 14 to 16 hours in summer.
The foraging trips that do occur in winter are often timed to coincide with the warmest part of the day rather than the typical nocturnal pattern, a reversal that reflects the need to maintain body temperature above the threshold for efficient muscle function and digestion. Cold muscles require more effort per digging stroke, and digestion is significantly slower at lower body temperatures in animals with reduced metabolic rates.
Rainfall and Termite Availability
Temperature is not the only seasonal driver. Termite and ant activity itself is seasonal, peaking during the summer rainfall season when colonies are expanding and forager numbers are highest. In winter, termites retreat deeper into mound structures and become less accessible. The combination of cold-induced activity reduction and reduced prey availability means winter is physiologically stressful for pangolins, and this is the period when underweight or injured animals are most likely to die.
Hyperthermia: The Summer Risk
While cold is the greater winter risk, summer in the South African lowveld brings the opposite danger. Ambient temperatures above 35 degrees Celsius, combined with direct solar exposure, can push a pangolin's core temperature toward 40 degrees and beyond. At this level, cellular enzyme function is compromised, and heat stroke becomes a real risk.
Wild pangolins manage this by remaining underground during the hottest parts of the day and by limiting basking sessions to the morning hours. They may also pant — a behaviour documented in ground pangolins at high ambient temperatures that uses evaporative cooling from the respiratory mucosa.
Pangolins confiscated from traffickers or rescued from snares in summer are at high risk of hyperthermia: the stress of handling, combined with confinement in poorly ventilated bags or boxes, can drive body temperature dangerously high within minutes. Field responders are advised to move pangolins to shade immediately and to wet the exposed skin — not the scales — with cool (not cold) water if overheating is suspected.
Captive Thermoregulation Management
Managing pangolin body temperature in captivity is one of the most technically demanding aspects of pangolin husbandry, and getting it wrong is frequently fatal. South African rehabilitation facilities typically maintain holding temperatures of 24 to 28 degrees Celsius for adult ground pangolins, with careful attention to eliminating drafts and providing insulated sleeping boxes that simulate burrow conditions.
Pangolins in captive care often show more extreme basking behaviour than wild animals, which may indicate that the thermal environment of the enclosure is cooler than optimal. Providing a basking lamp at one end of an enclosure — creating a thermal gradient so the animal can self-regulate — is now standard practice at accredited facilities.
Stress and Thermoregulation
A recently captured or highly stressed pangolin often fails to thermoregulate effectively. The physiological stress response — elevated cortisol, suppressed feeding and digestion, and altered metabolic rate — can interfere with normal thermoregulatory behaviour. An animal that should be basking may instead remain curled and immobile even in a thermally appropriate environment, leading to gradual heat deficit if ambient temperatures are low.
This intersection of stress and thermoregulation is one reason why the mortality rate of pangolins immediately post-confiscation is so high, particularly in cold or temperate countries where illegally traded animals may be held in unheated warehouses or shipping containers. The African Pangolin Working Group's emergency care protocols specifically address this: rapid warming, dark and quiet confinement, and immediate stress-reduction measures are the priority within the first hour of receiving a confiscated or injured pangolin.
FAQ: Pangolin Thermoregulation
What is the normal body temperature of a pangolin?
The core body temperature of a ground pangolin at rest ranges from approximately 33 to 36 degrees Celsius, lower than most mammals of similar size. During basking it may rise toward 37 to 38 degrees before the animal seeks shade or retreats underground.
Do pangolins hibernate?
African pangolin species do not hibernate, but they do reduce activity significantly during cold winter periods in South Africa, spending more time underground in thermally stable burrows and less time foraging on cold nights.
Why do pangolins bask in the sun?
Pangolins bask to raise their body temperature before a foraging session, as warmer muscles and a higher metabolic rate improve digging efficiency and digestive function. Basking also stimulates ectoparasite die-off on exposed skin.