Squirrels shake their tails to warn of predators, show agitation, or signal during courtship.
Reasons
- Warning: tail flagging alerts other squirrels and shows predators they’ve been seen. Squirrels do this with a bark.
- Distraction: sends a signal to a predator that it was seen.
- Agitation or frustration.
- Courtship and territory display.
- Warmth: the tail also works as an umbrella and blanket.
Research
A study on California ground squirrels found they heat the tail to confront rattlesnakes (infrared signal).
Tail
Tail helps balance when jumping and is used to communicate.
Species
Gray squirrels, red squirrels and ground squirrels.
Danger
Squirrels can carry parasites, so don’t touch them.
Reasons
Squirrels flick or shake their tails for several reasons:
- Alarm and warning: tail flagging signals to other squirrels that a predator such as a hawk, cat or dog is near. Gray squirrels flick the tail rapidly and give barking calls.
- Defense against predators: the tail flagging signals to the predator that it has been spotted, which discourages pursuit. Studies by Rebecca Rundus at the University of California, Davis, on California ground squirrels found that tail flagging directed at rattlesnakes discouraged the snake from attacking.
- Social communication: squirrels flick the tail in courtship, to show aggression to rivals, or to show dominance and territory.
- Heat signaling: California ground squirrels increase blood flow to the tail, making it hotter, which is detected by rattlesnakes’ infrared-sensing pits and seems to confuse or intimidate them.
- Balance: the tail helps a squirrel balance when running along branches and wires.
- Thermoregulation and warmth: they wrap the bushy tail around the body in cold, or use it as a shade or umbrella in sun.
Research
Rundus et al. (2007, Animal Behaviour) showed that ground squirrels with heated tails faced less aggression from snakes. Squirrels can also use their tails to signal to their young. A parachute-like tail also helps to slow a fall; squirrels can survive falls from great heights.
Tail
A squirrel’s tail has about 20 to 30 percent of its body length extra. The hairs are about 3 to 5 centimeters long. The tail can shed fur, and squirrels sometimes lose the tail to escape predators, but it does not regrow.
Species
There are over 200 species of squirrels worldwide: tree squirrels (gray, red, fox), ground squirrels, flying squirrels, chipmunks and marmots. Eastern gray squirrels can live up to 6 years in the wild and 12 or more in captivity.
Danger
Squirrel tail flicking is normal behavior. Do not feed or approach wild squirrels, which can bite and carry fleas or diseases such as tularemia, though rabies is very rare in squirrels.
Behavior research and species notes
Squirrels flick or shake their tails to communicate alarm, mark territory, signal aggression and warn about predators. Research by Rebecca Smith, published in the journal Animal Behaviour, found that California ground squirrels wave their tails faster and heat them up when facing rattlesnakes, because rattlesnakes sense infrared heat. Tail flagging may tell a predator it has been spotted, which can discourage an attack. Gray squirrels use tail flicks with chirps and barks as alarm calls. The tail also helps with balance when running along branches, shade and warmth in cold weather, and body communication between squirrels. A fluffy tail can be used as a blanket in winter. Squirrels can drop a tail to escape a predator, but it does not grow back. Wild squirrels may carry fleas and ticks, and they should not be handled, since bites can transmit disease.
Based on data from the journal Animal Behaviour and wildlife agencies
