It’s happened to us all: you try so hard not to break the tail when you catch an anole, but inevitably it happens to one. As readers of Anole Annals know, many species of lizards, including anoles, lose their tails as a defense mechanism. While losing a tail, called autotomy, has known detrimental effects on social status in males and reduced locomotor capacity, we know less about other potential costs for a strategy that is intended to keeps lizards alive to reproduce another day. McKenzie Quinn, an undergraduate in Michele Johnson’s lab at Trinity University, wanted to know how losing so much tissue, and then replacing it, might take away available resources from other important processes. She measured changes in egg number, egg size, body size, and fat mass in the liver over the course of three weeks after experimental removal of the tail in green anoles. These females were compared to a control group that did not have their tails removed.
Lizards who had their tails autotomized re-grew their tails over the course of the experiment, whereas control groups that had intact tails had minimal tail growth. Surprisingly, there was no difference between the two groups in any of the traits measured. Females with autotomized tails had just as much growth, just as many eggs of the same size, and just as much fat accumulated in the liver. This suggests that in a laboratory setting females are not taking resources away from growth and reproduction to re-grow a tail. Field studies and additional manipulations of resource availability in the future may help us understand what costs are associated with such an intriguing and seemingly costly defense strategy.