Graeme James Caughley - Paradigm

Paradigm

Caughley advocated the use of the Declining Population Paradigm in conservation biology. This paradigm seeks to discover why a population is declining and how to prevent further declines. This opposes the small population paradigm that seeks to determine how long a small population will last. The declining population paradigm is not overly theoretical and does not deal with population viability analysis, effective population size, minimum viable populations or problems related to genetics. Caughley pointed out that it did not require a model to go out and observe what was going on in a system (cause and effect), although this lack of a mathematical model hinders generalisations by requiring case by case assessments.

Shortly after the death of Graeme, Hedrick and colleagues argued against the declining population paradigm for what they called the inclusive population viability analysis (PVA) At a first reading it is difficult to discern what the counter argument is since they state that they agree with Caughley in that a broader understanding and synthesis of ideas is required. It is upon closer examination, however that the concept and statement that "one cannot always interpret the significance of deterministic factors unless a proper inclusive PVA is carried out". This paper was in reaction to Caughley's promotion of common sense and was written by those that encouraged the use of mathematical models. Caughley however, was not against mathematical models and used them to determine rates of increase, dispersal, fecundity, and mortality.

To truly understand the controversy one must read the two articles of "Viva Caughley!". Both articles were written as a rebuttal to Hedrick and colleagues, who claim that Caughley's ideas are overly simplistic. Clinchy and Krebs explain that in fact it was not simple enough and "the basic distinction in conservation biology is between field biologists and lab scientists". It then was a heated debate against those that used expensive modelling programs and those that went out to do the same thing with inexpensive tools purchased at a hardware store such as pvc pipe and bits of string. Upon careful observation there is little disagreement found between what Caughley said and the rebuttal that Hedrick and colleagues gave.