Birds and reptiles have similar tears to humans, study finds

Have you ever wondered have tears? Well, a study at the Federal University of Bahia in Salvador, Brazil has revealed that they not only have tears, but the composition of their tears is similar to that of humans.

The researchers collected samples of healthy animals’ tears from seven species of birds and reptiles, including macaws, hawks, owls, and parrots, as well as tortoises, caimans, and sea turtles.

And it found both similarities and differences to human tears that could be key to veterinary treatments and eye disease.

“Although birds and reptiles have different structures that are responsible for tear production, some components of this fluid (electrolytes) are present at similar concentrations as what is found in humans,” lead study author Arianne Oriá, said in a press release. “But the crystal structures are organized in different ways so that they guarantee the eyes´ health and equilibrium with the various environments.”

Although the tears of mammals like dogs and horses are more similar to humans, there are similar amounts of electrolyte fluid in the tears of birds, reptiles and humans (but birds and reptiles had slightly higher concentrations than humans).

The study of animal tears is important to insight into better eye treatments for both people and animals, as well as improve our understanding of animals’ evolutionary adaptations.