A new study has found that the body weight of elephants in zoos fluctuates greatly over a 100-month cycle. And that that fluctuation is directly related to elephants' teeth.
"The fluctuation is linked to the particular pattern of tooth change in elephants," reports Science Daily, "which results in them having more or less chewing surface available."
The study, released this week by the University of Zurich in Switzerland, notes, "The teeth of most mammals, including humans, are only replaced once in a lifetime, when the milk teeth give way to the permanent teeth. This one change is enough to adapt to the increasing size of the jaw. But elephants increase greatly in size and weight over the course of their lives -- from a starting weight of 100 kilograms to several tons in adulthood. One single change of teeth would not be enough for the enormous growth of the jaw."
It is unclear if this phenomenon takes place int he wild, as well. Notes the University of Zurich study, "As elephants [in the wild] reproduce all year round but do experience seasonal fluctuations in the amount of food available, animals of various ages and tooth stages have access to differing quality and quantity of food. The weight of these elephants is therefore influenced by other factors alongside the change of teeth. It is only in zoos, where food availability is comparatively stable, that the pattern can be clearly observed."