Advances in wildlife ecology and the influence of Graeme Caughley

Abstract

Graeme Caughley produced substantial advances in our understanding of interactions between large mammalian herbivores and the environments they occupy. The strength of his work lay in the logical approach to answering fundamental questions. While his life work contributed to our understanding of animal population dynamics, it is in the application of his research and ideas that we have greatly advanced the science of conservation biology. Two central legacies of Caughley's lifelong work are that an understanding of basic science leads to more appropriate management, and that underlying assumptions must be explicitly stated and tested. By arguing that efficient management of ecosystems requires an understanding of the underlying mechanisms, he moved forward the application of basic research to management. Future advances in wildlife conservation must focus on three aspects: (1) the rules for stability in ecosystems, and how humans cause instability; (2) the decline in native habitats, mostly from agriculture, and how to renew and reconstruct them while expanding threatened populations; and (3) how to breed species in captivity, and then reintroduce them as a last line of defence.

Demographic plasticity in an invasive species: The effects of time since invasion and population management history on beavers in Tierra del Fuego, Argentina

“…We also estimated generation time ( T ), life expectancy at birth ( e 0 ), and life expectancy at 3 years old ( e 3 )—the average age at which beavers potentially disperse and reach sexual maturity (e.g., Payne, 1989) as average life years (Caughley, 1977). Age frequencies represent true age distributions, because births occur in pulses at 1‐yr intervals (Brenner, 1964), reducing the underestimation of vital rates (Sinclair et al., 2006). On the other hand, as natural selection affects reproductive success, and this selective pressure is surpassed when the organism first reproduces (Pianka, 2011), we estimated the average time that the organism lives after producing offspring, as .…”

“…The persistence of a wild population depends on the evolved biological mechanisms between a species and its environment (Sinclair et al., 2006). Conservation and management practices (such as lethal control of exotic invasive species) require an understanding of how these mechanisms operate at the population level (Skalski et al., 2005).…”

Introduction

“…4 Some wildlife managers also exclude reptiles, such that the definition is limited to 'freeranging birds and mammals'. 5 From a legal perspective, the definition is not based on biology but on whether the animal is 'wild' in the sense of ownership. 6 An animal is 'wild' if it is not under direct human control, thereby excluding domesticated pets and farm animals.…”

Scientific contributions of citizen science applied to rare or threatened animals

“…Long‐term and large‐scale monitoring of wildlife populations is fundamental to learn more about subjects relevant to conservation, such as species range shifts, phenology, changes in community composition, and ecology of infectious disease (e.g., Dickinson et al., 2010 ; Nielsen et al., 2009 ; Sinclair et al., 2006 ). Such monitoring is crucial for understanding drivers of decline of rare or threatened species and for incorporating population trends into policy frameworks for legislative protection (Robinson et al., 2018 ).…”