Our home enjoys blessings from trees. Not our own trees, which are smallish, but those of our neighbours. The garden just over our back-garden wall sports several good size ones, mainly mango and curry leaf, some of them leaning over into our airspace. Right past that garden lies a narrow lane bordering a mansion compound with lots of really tall trees. They sway in the breezes blow and catch lovely late afternoon sun. They attract tons of birds: Green Imperial Pigeon, Crested Goshawk and Black-Hooded Oriole among the more charismatic.
And every few days come the langurs. Trees in the next-door garden become their bouncy castle and their salad bar. Sometimes they’ll stretch themselves into awkward positions to rip off a leafy twig just out of easy reach while identical-looking twigs sit right next to them. Why is that hard-to-reach one better? Pickiness continues as they sample their leaves and drop dozens of them into our garden with only one or two nibbles out of each. Who knew monkeys could be so keen for the perfect bite?
Their agility is astonishing and their leaping prowess makes the Hanuman legend easy to understand. (So-called ‘Hanuman’ langurs: close cousins of our locals.) I have seen one jump 20 feet from one roof to another while holding a baby! They scamper over house roofs all around us but would almost never come onto our property until recently. Our fierce, fearless Golden Retriever, Millie (could be short for ‘Militant’) goes eyeball to eyeball with cobras and one night killed an intruding civet cat in a fight that destroyed our vegetable patch, then left the bloodless corpse on our doorstep to appreciate when we woke up, having heard nothing of the dark struggle. Millie is very interested in these monkeys. She’ll watch them as long as they’re in her field of vision. Our Golden Lab, Clara, couldn’t be bothered.
Lately, we’ve kept Millie out of the back garden (which she likes to use for you-know-what) and the monkeys now sometimes use our house roofs as a highway. I don’t like it one bit: their spectacular leaps break roof tiles and I’m worried they’ll get into the house with their scary canines. I wouldn’t want to get between a mommy and her baby. They move back and forth on our garden wall and take samples from our lemon and narang trees. I recently observed a brief (and I do mean brief) copulation atop the wall. Another time, as my son and I were playing badminton, six or eight of them sat on the wall for a while just watching us. I got the distinct feeling they understood what we were doing.
Purple-faced langurs reside only in Sri Lanka. There seems to be a population explosion in our neck of the woods. The local troupe seems to harbor an adorable new baby every other month and their numbers seem bigger than they used to be. This distorts the larger picture, however. As a sub-species, Colombo’s western purple-faced langur rates as ‘critically endangered’ (highly likely to fall extinct in the near future). They list among the most highly threatened primates in the world. Their main challenge lies in habitat loss as roads and houses chew up their forest. Hence their frequent appearance in neighbouring trees.
Ninety percent of their range now lies in human-populated areas. Healthy gene flow suffers from confinement to isolated pockets of viable habitat. This increases disease vulnerability, among other ills.
On a certain day back in November 2020, I noticed something I have been tracking ever since. On the next-door property with the bouncy-castle trees sits a house, nobody living there for the past half-dozen years. There’s an upstairs set of windows, below which sits an air-conditioning unit on a shelf. That day, two or sometimes three langurs spent lingering interludes sitting atop the AC unit, appearing to look through the windows into the room there.
Nothing was happening inside, so what could be holding their interest? After watching a while, I caught sight of a langur face in the window. It dawned on me that these simians were gazing at their own reflections in the glass. Snapping away with my camera as they leaned in and fidgeted, I caught a pic of one of them licking its own reflection. My discussion of this episode appeared as ‘Monkey Mirror Test: Part I’ in the May 2021 issue of Echelon and in the July 10, 2021 issue of EconomyNext. I recap some of that discussion here.
For some five decades now, scientists have been experimenting with the Mirror Self-Recognition (MSR) test. They are looking for whether an animal is capable of grasping that it is seeing itself in a mirror. If so, we may perhaps infer that it is aware of itself as a self or maybe understands that it is an object in the outside world, not just a field of experience.
You put one or more animals of a particular species in front of a mirror and watch what happens. In a typical first reaction, an animal thinks it is encountering another animal of its species. It may squawk with aggression or manifest other social behaviours. Most species never move beyond this, but some begin trying to puzzle out what is going on.
MSR literature describes phases that may follow this first social response phase. A second phase involves physical investigation such as looking behind the mirror. A third phase entails repetitive motions intently observed. As with that mirror scene in the Marx Brothers film ‘Duck Soup,’ this apparition does whatever I do at exactly the same time. This ‘preening’ behavior gets characterized as Level One in what’s called ‘passing’ the mirror test. The animal seems aware of itself as a self because it understands that it is watching itself, if that makes sense.
For animals that reach this stage three, scientists introduce a confirmational phase four, typically embodied in the ‘mark’ exercise when it is possible. They place a visible spot on a part of the animal’s body that it cannot normally see—its forehead for example—and then leave it in front of the mirror. If the animal, upon seeing the mark in the mirror, then touches that spot on its own body, it must be grasping that the image in the mirror is itself. This could be called Level Two in passing the mirror test. Chimpanzees use mirrors to groom themselves, cleaning teeth for example, and to scrutinize their own genitals.
Scientists reason that an animal capable of understanding its own image possesses self-awareness: “ability to become the object of your own attention.” The conclusion seems plausible enough at first, but gets slippery as you keep thinking. Is self-recognition a discovery of self-awareness or is it a product of self-awareness already there? Does failing the test prove that an animal is not self-aware? A growing MSR literature reports findings and raises questions.
From my observations, I conjecture that our local langurs recognize themselves and so, according to MSR theory, possess this sense of selfhood. Licking your own reflected tongue looks possibly like passing a self-administered version of the mark test.
Most animals seem not to pass the test, dogs and cats for example, and several species of primates. Bonobos pass the test along with their chimp cousins, orangutans as well. (Visiting London Zoo in 1938, Charles Darwin watched an orangutan make faces at its image in a mirror.) Bottlenose dolphins and orcas pass versions of the phase-four mark test. At least one Asian elephant like those found in Sri Lanka appears to pass the test. First non-mammals to pass the test, Eurasian magpies try to remove coloured stickers from their feathers while viewing them in a mirror. Manta rays—fish with big brains featuring neurons structurally similar to those of birds and mammals—exhibit energetic preening behaviour, such as blowing bubbles at their images. Scientists count this as passing the test. They link success on the test with large ratios of brain to body size (‘encephalization quotient’), with high intelligence and with social sophistication.
For capable primates, reflection recognition may well predate modern testing. Long before mirrors and glass windows there were pools of clear still water. I once observed two lapwings standing at the edge of a swimming pool, their reflections clearly visible, doing a whole lot of nothing for hours. Were they puzzling over their birdy reflections?
Since that first observation, I have witnessed langur glass-gazing a number of times. One day last May, one baby and two grown-ups sat atop the AC unit together, peering intently. Multiple participants may help precipitate recognition of one’s own reflection. (That reflection looks like Bilbo to my right and this one looks like Freyda to my left, so the one in the middle must be….Hey, not too bad-looking either!) Maybe they experience a shadow world where doppelganger versions of themselves live mysteriously. (Deep origin of religion?) That day one of the big ones began licking the glass rapidly while the baby, up on hind legs, seemed to grapple with the apparition or try to get through the glass. Later, the baby by itself either waved to its reflection with its right forepaw or else reached to touch its reflection.
On an August day last year, one monkey sat gazing at the glass for long moments while the rest of the troupe ate and frolicked. It broke off to join others in a tree, then returned briefly to the AC unit before moving off with the troupe. Around noonish on a January day this year, a 15-monkey troupe occupied their bouncy castle. They seemed to be suffering an outbreak of ‘zoomies,’ what my son calls it when one of our dogs takes to running madly around the house and garden for no apparent reason.
They’ll steal twigs from or slap one another to provoke chases through the branches. Babies especially seem to relish long tumble-downs before grabbing something to break their fall. Sometimes two facing each other will jump up and grapple a bit in the air. Youngsters get atop house walls too high for jumping by climbing hand over hand up a grown-up’s dangling tail. Then, likely as not, they’ll jump back to the trees.
That day, three langurs in succession leaped atop the AC unit, glanced into the glass for a few seconds, then moved off. A few minutes later, there was a fourth visit. This visit, more prolonged, was divided between glass-gazing and turning around to monitor an apparent altercation.
The fact that three visitors seemed so ho-hum about the image in the glass might seem to indicate that they do not recognize themselves. (Or maybe they do but they’re quickly taking turns.) Another fact may also point to non-recognition. Most times when the troupe turns up, no one visits the AC unit. If they were recognizing themselves, you would think they would be doing it all the time. Expert Frans De Waal suggests that self-awareness among primates may be not a ‘yea’ or ‘nay’ thing but rather a ‘more or less’ thing. I have found no literature on mirror testing with langurs.
I obviously cannot conclude with any certainty that langurs I’m watching recognize themselves or possess a sense of self-awareness. One characteristic, however, makes it likely that they might: langurs are highly allomaternal, meaning that baby caregiving comes not just from mommies but also from aunties and juvenile kin females and sometimes from males as well. This is a fairly rare trait. Human childcare is allomaternal of course.
Most monkey mothers strongly resist letting other females handle their infants. Allomaternal mothers do so liberally and without anxiety. I have seen our local langurs passing babies among themselves on multiple occasions. Trust among sisters lies deep. Scientists suggest that allomaternal care fosters emotional empathy, social learning and high intelligence. Several species credited with passing the mirror test–including orcas, bottlenoses, elephants, bonobos and magpies– manifest allomaternalism. All are notoriously intelligent.
Self-awareness may go with recognition that other animals—at least those in one’s own species—are also selves of their own. It may foster ‘theory of mind’—comprehension that other animals have desires and intentions, along with accurate grasp of what those might be. This may correlate with empathy and generosity: sharing of benefits and assistance in peril.
Possible self-awareness is one reason why we should study and take care of our local langurs. Another is that we have destroyed their homes.
Author, lawyer and former law professor, Mark Hager lives in Pelawatte with his family.
https://www.linkedin.com/in/mahager/
Further Reading
Hrdy, Mothers and Others (allomaternalism)
De Waal, Mama’s Last Hug (animal emotions)
Andrews, The Animal Mind
Keenan, et. al., Self-Face Recognition and the Brain
Roonwal & Mohnot, Primates of South Asia
Yapa & Ratnavira, Mammals of Sri Lanka
Parker, et. al., ‘When there is no forest left: fragmentation, local extinction and small population sizes in the Sri Lankan purple-faced langur’
Rudran, ‘A survey of Sri Lanka’s endangered and endemic western purple-faced langur’
Organizations and Resources
Wildlife and Nature Protection Society (Sri Lanka)
Sri Lanka Wildlife Conservation Society (Sri Lanka)
Department of Wildlife Conservation (Sri Lanka)
Dilmah Conservation (Sri Lanka)
New England Primate Conservancy (U.S.)
International Union for Conservation of Nature (Worldwide: local office in Pelawatte)