Desert kangaroo rats ninja-kick attacking rattlesnakes
A desert in the southwestern United States may be the lair of secret ninja masters. You know them as desert kangaroo rats. But a pair of new studies finds that these rodents can bust out complex moves to avoid deadly rattlesnake bites.
Clashes between these rodents and rattlers happen at lightning speed. Researchers weren’t sure how the rats dodged death. Now, high-speed cameras offer the first detailed look at their tricks. The findings were published online March 27 in the journals Functional Ecology and the Biological Journal of the Linnean Society.
Scientists knew that keen hearing and foot tapping help desert kangaroo rats keep predators away. But those tactics don’t always work, notes Rulon Clark. He’s a behavioral ecologist at San Diego State University in California.
Clark and his team had seen snakes ambush rats in the wild. They watched as many rodents jumped and darted away unharmed. To get a closer look, the scientists trekked into the Sonoran Desert in Yuma, Ariz. They lugged along high-speed cameras. Using them, the researchers caught 32 brawls between desert kangaroo rats (Dipodomys deserti) and sidewinder rattlesnakes (Crotalus cerastes). The footage revealed the rats’ defensive moves.
Rats twisted their bodies in midair to dodge the lunging rattlesnakes’ fangs. Even when snakes landed a bite, some rats kicked off their foes. Just in time, too. Snakes couldn’t always bite long enough for the rats to get a deadly dose of venom.
The kicking was one of the biggest surprises. “We didn’t expect it would be so effective,” says Grace Freymiller. She is also a behavioral ecologist at San Diego State University.
After dodging rattlesnakes’ fangs, the rodents used their tails to shift their bodies. They landed on their feet and quickly retreated.
All of that evasion happens faster than the blink of an eye. One rat reacted to a snake’s lunge in just 38 milliseconds. Desert kangaroo rats are “clearly pushing the envelope” of reaction time among vertebrates, Clark says.
behavioral ecologist A scientist who studies how animal behavior relates to where animals live.
ecology A branch of biology that deals with the relations of organisms to one another and to their physical surroundings. A scientist who works in this field is called an ecologist.
footage (in movies and videos) A term for the uncut or unprocessed motion pictures or video imagery taken by a camera. It takes its name from the fact that it took several feet of film to capture a few seconds of motion-picture photography.
journal (in science) A publication in which scientists share their research findings with experts (and sometimes even the public). Some journals publish papers from all fields of science, technology, engineering and math, while others are specific to a single subject. The best journals are peer-reviewed: They send all submitted articles to outside experts to be read and critiqued. The goal, here, is to prevent the publication of mistakes, fraud or sloppy work.
millisecond A thousandth of a second.
predator (adjective: predatory) A creature that preys on other animals for most or all of its food.
rodent A mammal of the order Rodentia, a group that includes mice, rats, squirrels, guinea pigs, hamsters and porcupines.
tactic An action or plan of action to accomplish a particular feat.
venom A poisonous secretion of an animal, such as a snake, spider or scorpion, usually transmitted by a bite or sting.
vertebrate The group of animals with a brain, two eyes, and a stiff nerve cord or backbone running down the back. This group includes amphibians, reptiles, birds, mammals and most fish.
Journal: M. Whitford et al. Determinants of predation success: How to survive an attack from a rattlesnake. Functional Ecology. Published online March 27, 2019. doi: 10.1111/1365-2435.13318.
Journal: G. Freymiller et al. Escape dynamics of free-ranging desert kangaroo rats (Rodentia: Heteromyidae) evading rattlesnake strikes. Biological Journal of the Linnean Society. Published online March 27, 2019. doi: 10.1093/biolinnean/blz027.