If you’ve spent ever a little time around parts of the internet that deal with elephant advocacy, you’ve probably seen the stock photo above: liquid clearly running out of the inner corner of an elephant’s eye, looking for all the world like crying. It’s pretty much the go-to image for pieces about emotional complexity in elephants, and is generally used to represent the fact that people think they can cry tears of emotion. Except if you’ve spent any time at a zoo or around people who work with elephants, they’ll tell you elephants can’t cry because they don’t have the right physical structures. So what gives? The answer turns out to be, effectively, that going semi-aquatic for a while in your evolutionary history fucks up a perfectly good tear-producing system, and that effective science messaging is really hard. So. Uh. I went down a rabbit hole and spent two weeks researching how elephant eyeballs keep themselves wet. It’s actually pretty fascinating science, but since the above article I wrote is pretty technical, here’s a more casual rundown.
Humans (and most mammals) produce most of our tear fluid from a big gland under the outer part of our eyebrows. It drains onto the eye, spreads across it when we blink, and normally just drains away into our nasal cavity through those tiny holes in the inner corners of our eyes. If our eyes get irritated, we produce more liquid to flush out whatever is in them; if we’re in an emotional state, the “calm yourself back down” part of the fight-or-flight reflex system makes the gland overproduce liquid that’s full of hormones and painkillers and stuff. In the latter case, the drainage canals in our eyes get overwhelmed by the amount of liquid produced, and you get the whole tears spilling out of your eyes thing.
Tear fluid isn’t just liquid in your eyes – it’s actually a pretty complicated three-layer setup. Each layer is produced by a different type of gland and has a different purpose: mucous helps make sure tears spread evenly, then you’ve got the actual aqueous stuff which is anti-bacterial, and then oil on top of the watery stuff keeps the liquid from evaporating or falling out of your eyes all the time.
Probably during the period of time when it’s thought the ancestors of elephants were semi-aquatic, they basically threw that entire system out of the window. Having a modified lacrimal apparatus (the set of glands and canals that are involved in tear production) appears to be a fairly normal thing for semi-aquatic mammals: modern pinnipeds don’t have an oil layer on their tear film, because when you’re underwater a lot you don’t need to worry about your eyeball lubrication evaporating. (This is why pinnipeds, when on land, appear to always be crying – there’s no lipid barrier creating surface tension and keeping the fluid on the eye.) Except… the ancestors of elephants got rid of the whole water-based tear-producing system, not just the lipid layers. Including the drainage system at the corners of their eyes. And then, eventually, evolved to be terrestrial again.
So, in absence of the normal glandular system for lubricating their eyes, elephants… appear to have basically hijacked a bunch of the glands they did have left (one on the third eyelid, as well as ones external to the eye that normally lubricate the eyelashes) and started using them to keep their eyes moist. Because these are modified skin glands, they produce really weird fluid – lovely combinations of watery liquid and mucous and sebum. But, because elephants no longer have those drainage systems for tear fluid, it doesn’t have anywhere to go; their watery eyeball goop builds up and then spills out of their eyes at the inner corner. There’s actually a specific groove in the skin that moves it diagonally away from the eye in both species, which is why the spilled fluid tends to look like “tear tracks” rather than just a wet mess near the eye.
TL;DR: when it looks like an elephant is crying, that’s just the regular eyeball moisture draining out visibly because they don’t have canals to carry it into the nasal passages like most mammals.
Here’s some other fun stuff about eyeballs and elephants and crying that made the above overview a bit overwhelming when I tried to include them in paragraph form:
Without a lacrimal apparatus, elephants can’t produce emotional tears – the glands that normally get a message from the brain that says ‘hey you should produce sad tears now’ are just straight up non-existent.
The white stuff that accumulates at the corners of their eyes is likely to be the mucous and sebum from the tear fluid that hasn’t evaporated; there’s no academic literature addressing it, but it occurs more on windy days when their eyes would be producing more tear film to remove irritants,and the elephant care staff I’ve talked to said it’s considered to be a normal occurrence.
The drainage from glands on the side of an elephant’s head is also not crying! It’s fluid seeping from a modified sweat gland, which (in African elephants) is actually triggered by the other end of the fight-or-flight system from crying; they start draining from their temporal glands during periods of high internal arousal, but it’s the “okay time to get amped” sympathetic nervous system that makes it happen – crying is a parasympathetic nervous system response that serves to help humans calm back down after a stressor.
Asian elephants don’t actually generally from their temporal glands during strong emotion! Females rarely, if ever, produce fluid from them, and males generally only have discharge present fro them when they’re in musth.
We don’t actually know a lot about the purpose of the temporal glands in elephants. It’s hypothesized that the secretions from them are some sort of chemical communication, but more research is needed.
EDIT: tear duct appears to be a colloquial term that is used to reference both the little tubes between the gland that creates tears and the surface of your eye, and the duct that drains tears into the nasal cavity of both mammals. This is part of the confusion around the term. Either way, saying “elephants don’t have tear ducts” is an interesting way of phrasing things, because what’s more important is that they also don’t have the gland that creates tears.
Second TL;DR: Don’t trust information from any “elephant expert” who attempts to claim that elephants cry emotional tears. It’s just straight up anatomically impossible, and the “alternate” (temporal gland drainage) isn’t analogous to the internal states in which humans cry. Anyone who purports that elephants cry emotionally either hasn’t done their research or is purposefully misrepresenting normal elephant physiology as a manipulation tactic.
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