Never smile at a crocodile?

SES, 26 March 2021

‘Fake tears’ provide real research results…

Accusing someone of shedding ‘crocodile tears’ traditionally meant they would have been faking their grief, these insincere tears paralleling the ancient (and erroneous) belief that these animals shed tears as they consume their prey. With new research providing further insight into the nature of these tears, now might be the time to revise our perceptions of their worth…

There have been conflicting theories throughout history as to why crocodiles appear to cry. Some believed it was simply due to their appearance after leaving a river. However there is some evidence tears can be triggered in crocodiles while they feed. There is even a medical condition in humans colloquially known as “crocodile tears syndrome”: Bogorad’s syndrome, which is a rare condition that causes people to cry when eating food.

Tears aren’t just for emotional times. Nor are they solely a human phenomenon. All vertebrates have tears. And, like these animals, crocodiles will weep to lubricate their eyes – especially when these eyes dry out after the animal has been on land for a considerable period of time.

Now a study by Brazilian veterinarians has identified that the chemical makeup of these tears are strikingly similar to those of humans. The study, published in the journal Frontiers in Veterinary Science, identifies reptiles and birds with unique tear crystallization patterns that help specific animals keep their eyes wet and healthy.

The National Geographic article states that “The research illustrates how little we know about tears and how they work in humans and other animals, notes Brian Leonard, a veterinary ophthalmologist at the University of California, Davis. “It’s an important but massively poorly understood field,” he says, “so this study is interesting on multiple levels.”

It is hoped that further analysis may provide advanced treatments for human eye disease in the future. So it might be that ‘crocodile tears’ in the future could be seen as helpful ones – at least for dry eye sufferers.