Data from: Cut your losses: self-amputation of injured limbs increases survival

Autotomy, self-induced limb loss, is an extreme trait observed throughout
the animal kingdom; lizards drop their tails, crickets release their legs,
and crabs drop their claws. These repeated evolutionary origins suggest
that autotomy is adaptive. Yet, we do not have a firm understanding of the
selective pressures that promote and maintain this extreme trait. Although
multiple adaptive hypotheses exist, research has generally focused on
autotomy’s adaptive value as a form of predator escape. However, autotomy
could also be selected to reduce the cost of an injured limb, which we
investigate here. Previously, this alternative hypothesis has been
challenging to directly test because when an injury occurs on an
autotomizable limb, that limb is almost always dropped (i.e., autotomy is
behaviorally fixed within populations). Recently, however, we have
identified a species, Narnia femorata (Insecta: Hemiptera: Coreidae),
where some individuals autotomize limbs in response to injury, but some do
not. This natural variation allowed us to investigate both the survival
costs of retaining an injured limb and the benefits of autotomizing it. In
this study, we find a positive association between autotomizing injured
limbs and survival, thereby quantifying a new and likely widespread
benefit of autotomy—reducing the cost of injury.