A Lizards Expendable Tail
by: Lizard Lounge
Some lizards when confronted with a predator will
voluntarily shed their tail. This process is called tail
autotomy (self-cut). After the tail is detached from the
body it will wiggle around on the ground for a few
minutes. This provides a visual distraction and draws
attention away from the vulnerable head and abdomen of
the lizard. Usually this allows the lizard enough time
to make an escape.
Not all lizard species are capable of doing this, the
ones that can have fracture points in their vertebrae.
The lizard’s blood vessels in the tail area rapidly
constrict after autotomy to ensure minimal blood loss.
The muscles in this area are also adapted to provide
easy shedding of the tail.
After a lizard drops its tail it will start to grow
back a new one, however the new one will not look the
same as the original. It may have different colors,
shape and size. Sometimes multiple tails will grow in
the place of the one that was dropped. The new tail is
able to perform all the functions of the original with
the exception of autotomy. That’s because the new tail
does not have any fracture points in the vertebrae. For
some legless lizards their tail can make up almost 2/3
of their body length, so loosing it can be a stressful
ordeal.
The whole process of shedding its tail can be very
stressful to the lizard. If this happens while in
captivity it is generally a result of stress and careful
evaluation of the situation is required to ensure that
it does not happen again. A lizard that has recently
shed its tail should be kept in its own enclosure while
it re-grows the tail. Ensure that this enclosure is kept
clean to minimize the chance of infection. Growing a new
tail requires the expenditure of a great deal of protein
(energy) and fat. This is compounded by the fact that
the tail stores a lot fat which is no longer with the
lizard. It is widely believed that the energy required
to re-grow a tail can negatively effect the reproductive
cycle. This happens because the lizard is unable to put
enough energy into producing the eggs. In some cases it
may take the lizard up to 2 years to completely re-grow
the tail.