NOV 18, 2016 7:21 AM PST

How Vomiting Evolved to be a Defensive Mechanism

WRITTEN BY: Xuan Pham

For some animals that don't have sharp teeth or claws, or other types of classic defense mechanisms, evolution has helped them build a new way to defend themselves. Think nasty, pungent, slimy, and even corrosive barf. Yes, this is a defense mechanism, and it's pretty effective too!

This strange coping strategy is popular among many bird species. For example, vultures are known to induce vomiting as a way to drive away predators. Furthermore, the vulture's emesis is highly acidic, ranging between pH 1 and 2. This is enough to burn some thin-skinned predators if they happen to venture too closely to the vulture.

Other birds that use their stomach content as natural "pepper spray" include herons, gulls, and the European roller.

Interestingly enough, if vomiting is considered a defense mechanism, then some people would also consider human morning sickness during pregnancy a form of defense barfing. Though the act isn't directed at any one predator, per se, the common nausea and vomiting in the early trimesters may be a way to protect the mother-to-be and fetus from potentially toxic foods.
About the Author
  • I am a human geneticist, passionate about telling stories to make science more engaging and approachable. Find more of my writing at the Hopkins BioMedical Odyssey blog and at TheGeneTwist.com.
You May Also Like
DEC 10, 2020
Plants & Animals
The Surprising Way Honeybees Protect Hives from Hornets
DEC 10, 2020
The Surprising Way Honeybees Protect Hives from Hornets
"Murder hornets," more commonly known as giant hornets, might be new to North America, but in their native ran ...
FEB 10, 2021
Space & Astronomy
Do Salt and Melting Ice Cause Landslides on Mars?
FEB 10, 2021
Do Salt and Melting Ice Cause Landslides on Mars?
Recurrent slope lineae (RSL) are dark flows that extend downhill on Mars to form sandy patterns on its surface. Research ...
APR 17, 2021
Space & Astronomy
Dent in Earth's Magnetic Field Caused by Buried Ancient World
APR 17, 2021
Dent in Earth's Magnetic Field Caused by Buried Ancient World
Researchers from Arizona State University have suggested that two giant blobs of rock cupping the Earth's core are l ...
MAY 15, 2021
Space & Astronomy
Earth's Core has 70 Times More Hydrogen than the Oceans
MAY 15, 2021
Earth's Core has 70 Times More Hydrogen than the Oceans
Researchers from the University of Tokyo have found that under certain extreme conditions, hydrogen particles can bond s ...
JUN 24, 2021
Space & Astronomy
European Space Agency to Launch Satellite Made from Plywood
JUN 24, 2021
European Space Agency to Launch Satellite Made from Plywood
Modern spacecraft are typically made out of carbon fiber composites. Now, however, the European Space Agency has announc ...
OCT 15, 2021
Health & Medicine
The Art of the Smize: Study Shows Eyes are More Active in Smiling Behind a Mask
OCT 15, 2021
The Art of the Smize: Study Shows Eyes are More Active in Smiling Behind a Mask
Mask wearing has become a part of our everyday lives. Something that we have all adapted to because of this is expressin ...
Loading Comments...