Real World Irruption

Irruptive population growth is easy to plot with pen and paper but does it exist in the real world?  The answer is a very definite "Yes" and some predators are experts at it.

In August 2017 we posted about the exponential growth potential of populations that ecologists call an irruption. These generate a characteristic 'J’ shaped growth curve, or “hockey stick” graph of population size over time. While these curves are easy to plot with a calculator and a sheet of graph paper, do they actually exist in nature?

Data from one of our own rodent control programmes demonstrates just how quickly an irruption can occur for fast breeding predators such as rodents. The control site was an area of regenerating coastal kanuka forest in Northland where the abundance of rodents was monitored monthly using 75 double snap trap stations spaced along a 1.5km trapline

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