The textbook example of population modeling is the predator-prey cycle, in which the rise and fall in the number of prey causes a delayed rise and fall in predators.

A recent study of lions on the Serengeti plains has found a wrinkle in this simple picture.  The number of lions makes sudden jumps - even when the food supply changes gradually. 

The difference seems to be tied to the fact that when a pride reaches a certain size, some females will split away and start a new one. 

But for the new pride to be successful, there needs to be enough males to defend food, water and good sites for dens. 

By assuming, therefore, that there is an upper and a lower limit to pride size, Craig Packer of the University of Minnesota and his colleagues found they could predict the leaps in lion populations over recent decades.

The results were published in an article in today's Science journal.

-- LiveScience Staff

Credit: Science