Tail autotomy works as a pre-capture defense by deflecting attacks

Caudal autotomy is a dramatic antipredator adaptation where prey shed
their tail in order to escape capture by a predator. The mechanism
underlying the effectiveness of caudal autotomy as a pre-capture defense
has not been thoroughly investigated. We tested two non-exclusive
hypotheses, that caudal autotomy works by providing the predator with a
‘consolation prize’ that makes it break off the hunt to consume the shed
tail, and the deflection hypothesis, where the autotomy event directs
predator attacks to the autotomized tail enabling prey escape. Our
experiment utilized domestic dogs Canis familiaris as model predator
engaged to chase a snake-like stimulus with a detachable tail. The tail
was manipulated to vary in length (long vs. short) and conspicuousness
(green vs. blue), with the prediction that dog attacks on the tail should
increase with length under the consolation prize hypothesis, and
conspicuous color under the deflection hypothesis. The tail was attacked
on 35% of trials, supporting the potential for pre-capture autotomy to
offer anti-predator benefits. Dogs were attracted to the tail when it was
conspicuously colored, but not when it was longer. This supports the idea
that deflection of predator attacks through visual effects is the prime
antipredator mechanism underlying the effectiveness of caudal autotomy as
opposed to provision of a consolation prize meal.