How Pangolins See at Night: Eye Anatomy and Nocturnal Adaptations

Published 14 June 2026 — alphapanga.com

Camera trap photographs of pangolins almost always share a distinctive quality: the animal is captured in infrared flash illumination with two small bright points of reflected light — the eye shine produced when light bounces off the tapetum lucidum, the reflective membrane behind the retina. This eye shine confirms that pangolins, like cats, dogs, and many other nocturnal mammals, possess this light-amplifying tissue. Beyond that single optical feature, the visual biology of pangolins remains remarkably poorly characterised. In an era when the genome sequences of multiple pangolin species have been published and their scale chemistry analysed in detail, the basic structure and function of the pangolin eye has received almost no systematic scientific attention.

Small Eyes in a Sensory Hierarchy

Pangolin eyes are conspicuously small relative to body size. Across the eight pangolin species, the eye diameter is modest and does not approach the proportionally large eyes of highly visual nocturnal predators such as owls, tarsiers, or bushbabies. Eye size in nocturnal animals is a reliable indicator of the evolutionary priority placed on vision: species that depend heavily on sight in low light conditions evolve large corneas and large lenses to maximise photon capture. Pangolins have not followed this trajectory, which immediately signals that vision is not their primary foraging sense.

This inference is consistent with field behavioural observation. Pangolins locate insect nests primarily through olfaction. The long, convoluted nasal passages of pangolin skulls — well documented in osteological studies — bear the elaborate turbinate bones that support a large olfactory epithelium surface area. The vomeronasal organ, or Jacobson's organ, which detects non-volatile chemical cues and pheromones, is present in pangolins and likely plays a role in locating foraging sites and in social communication. When a pangolin approaches a termite mound or ant colony, it is following an olfactory trail, not a visual one.

The Tapetum Lucidum: How It Works

The tapetum lucidum is a layer of reflective cells positioned immediately behind the retina. When a photon enters the eye and passes through the retina without being absorbed by a photoreceptor, the tapetum reflects it back through the retina for a second pass, roughly doubling the probability of photon detection. This doubles the eye's effective sensitivity to low-intensity light at the cost of some spatial resolution, because the reflected beam does not retrace the exact path of the incoming light, introducing a slight blurring of the image.

The tapetum's composition varies across species. Felid tapeta are composed of zinc-containing crystalline riboflavin, which produces the characteristic green or yellow-green eye shine of cats. Canid tapeta are composed of zinc cysteine. Bovid tapeta are cellular rather than crystalline. The specific composition of the pangolin tapetum has not been published to our knowledge, though the distinctive eye shine captured in camera trap images suggests it is well developed and likely a cellular or crystalline type producing a pale green or yellow reflection.

Eye shine colour varies with species, individual, and the angle of illumination, so camera trap images alone cannot determine tapetum composition. Histological examination of preserved pangolin eyes — from captive deaths or confiscated animals that do not survive rehabilitation — could resolve this definitively. Given the conservation value of pangolin tissue samples, eyes from mortalities at rehabilitation centres represent an underutilised research resource.

Photoreceptor Architecture: Inference Without Data

In the absence of published histological studies of pangolin retinas, the composition of the photoreceptor layer — the relative density of rods and cones, which determines the trade-off between light sensitivity and colour vision — must be inferred from evolutionary context. Strictly nocturnal mammals typically have rod-dominated retinas with few or no cone types, sacrificing colour discrimination for maximum sensitivity in dim light. Some primarily nocturnal species retain a dichromatic cone system — two cone types, typically sensitive to short-wavelength and medium-wavelength light — that provides limited colour vision in brighter conditions.

Pangolins are primarily nocturnal but some species show crepuscular activity — a preference for the low light conditions of dawn and dusk rather than full darkness. The Sunda pangolin (Manis javanica) has been recorded active during daylight hours in some environments. A retina architecture with a modest cone complement would be consistent with this behavioural flexibility, providing some colour vision capacity when ambient light levels are sufficient while maintaining rod-based sensitivity for fully nocturnal foraging.

Electroretinography — measuring the electrical response of the retina to light stimuli of different wavelengths and intensities — has been used to characterise photoreceptor function in zoo animals across dozens of species, including armadillos, aardvarks, and other insectivores with which pangolins share ecological niches. To our knowledge, no electroretinographic study of any pangolin species has been published in a peer-reviewed journal. This is a gap that could be addressed using sedated animals at zoological institutions with pangolin collections.

Pupil Shape and Optical Design

The shape of the pupil provides information about how an animal uses its visual system. Vertical slit pupils, characteristic of ambush predators like cats and vipers, produce exceptional depth-of-field control at close range while still allowing rapid dilation for low-light sensitivity. Round pupils, typical of larger predators and diurnal species, allow more uniform light collection across the visual field. Horizontal slit pupils, found in grazing prey species like goats, provide a wide panoramic field and excellent detection of approaching predators in the horizontal plane.

Pangolin pupil shape is not consistently documented in the literature. Close-up photographs of pangolin eyes suggest a roughly circular or somewhat ovoid pupil shape when the pupil is dilated in low light, which would be consistent with a generalist nocturnal visual system focused on sensitivity rather than optical specialisation. Photographs under brighter conditions, which would reveal how the pupil constricts, are uncommon because pangolins typically become inactive and curl defensively when exposed to bright light.

This light-avoidance behaviour is itself informative. Captive pangolin behaviour studies note that individuals become active immediately when enclosure lighting is reduced to near-darkness or turned off, and remain inactive and stressed when exposed to normal room lighting. This response pattern is more extreme than in many nocturnal species that tolerate moderate light levels. It suggests that the pangolin visual system may be adapted for very low light conditions and may experience bright illumination as genuinely aversive, whether through photoreceptor saturation or through a learned association between brightness and daytime danger.

Hearing and the Full Sensory Picture

Understanding pangolin vision requires placing it within the full sensory context. Field behavioural evidence suggests that pangolins rely on a hierarchy in which olfaction is primary, hearing is secondary, and vision plays a supporting role primarily in detection of large-scale movement at close range.

The external ears of pangolins are small but visible, particularly in the African species. Pangolins seal their ear canals when foraging at insect nests, protecting against biting insects, but at other times their hearing appears active and sensitive. Pangolins in rehabilitation facilities react to rustling sounds at distances that imply hearing sensitivity in the mid-frequency range, and they detect approaching humans before visual contact. The Middle Ear morphology of pangolins, which has been characterised in a small number of osteological studies, shows the enlarged cochlear structures typical of good low-frequency hearing, useful for detecting ground vibration and low-pitched sounds in the forest environment.

Olfaction integrates with hearing to provide a rich situational awareness that compensates for limited visual acuity. A pangolin approaching a termite mound in full darkness can smell the mound from tens of metres, hear the colony activity within it from several metres, and use vision only to navigate the final approach and confirm the presence of large obstacles. This sensory division of labour is economically efficient: maintaining large, energetically expensive eyes makes little sense when the foraging ecology does not reward fine visual discrimination.

Rehabilitation and Captive Management Implications

The practical implications of pangolin visual biology for captive management and rehabilitation are significant. Facilities receiving pangolins from trafficking seizures need to manage light environments carefully. Standard wildlife rehabilitation protocols designed for diurnal or generalist species often involve bright examination lights, daylit enclosures, and overhead fluorescent lighting in treatment rooms. For pangolins, these conditions are physiologically stressful and may contribute to the high mortality rates observed in confiscated animals at poorly equipped facilities.

Best-practice rehabilitation centres now use dim red-spectrum lighting for nocturnal species, including pangolins, based on the principle that mammalian rods are less sensitive to long-wavelength red light and that animals therefore experience red-lit environments as functionally darker than white-lit ones. The extent to which this approach specifically benefits pangolins depends on the spectral sensitivity of their photoreceptors — a question that, as noted, has not been formally answered. Red-light protocols are nonetheless a reasonable precautionary standard pending proper photoreceptor characterisation.

Enclosure design recommendations from African Pangolin Working Group guidelines consistently emphasise dark burrow areas, minimal daytime disturbance, and observation through infrared cameras rather than direct visual monitoring. These recommendations are based on accumulated rehabilitator experience rather than formal visual biology research, but they represent the field's best current integration of what is observationally known about pangolin light sensitivity.

The Research Opportunity

Three studies could substantially advance understanding of pangolin visual biology with relatively modest investment. First, histological examination of retinas from pangolin mortalities at major rehabilitation centres in South Africa, China, and Vietnam would characterise photoreceptor composition and retinal layer architecture. Second, electroretinographic studies at accredited zoological institutions with anaesthetised pangolins under husbandry sedation would quantify spectral sensitivity and temporal resolution. Third, genomic analysis of opsin genes — the light-sensitive proteins in photoreceptors — from published pangolin genome sequences could predict which wavelengths different pangolin species are sensitive to, providing a genomic complement to the anatomical studies.

These studies would not only satisfy basic scientific curiosity. They would provide the quantitative foundation for evidence-based captive management protocols, contribute to the broader comparative ophthalmology literature on mammalian nocturnal adaptation, and potentially reveal whether different pangolin species — particularly the contrast between ground-dwelling African species and arboreal Asian species — have evolved distinct visual systems in response to their different light environments.

For related pangolin biology see our articles on acoustic monitoring research, pangolin muscle anatomy, and the pangolin tongue.