Introduction

For hundreds of millions of years, the earth has been the dominion of giants. From the prodigious arthropods of the Cambrian, to the ginormous sharks of the late Miocene, to the Blue Whale of the Anthropocene, our oceans have teemed with substantial life. Our landscapes have borne witness to dinosaurs, massive hornless rhinos, mammoths, Ground Sloths, and elephants. Even our skies have played host to the likes of argentavis magnificens (the biggest bird of all time), pterodactyls and albatrosses.

Through ice ages, meteor strikes (potentially), changes in climate, and more, the presence of megafauna has been near-continuous, conspicuous and crucial. Yet in the past ~50,000 years, a mere instant in geological and evolutionary terms, their profusion and diversity has decreased dramatically. Megafaunal biomass has shifted disproportionately towards a new species of megafauna, if not as giant in stature and longevity as many of its fellows and contemporaries, arguably more monstrous in terms of profound effect on the Earth than any before. This wildly successful outfit to whom allusion is made, so gargantuan in its earthly footprint as to (somewhat arguably) merit the denotation of a new geologic epoch, is of course humankind.

Estimated human biomass plotted against estimated non-human megafauna biomass (Barnosky et al,  2008)

This transition is by no means without consequence, for our world and indeed our species. And for all of our success, complexity and proliferation, when faced with the task of filling in the footsteps of our fellow megafauna, we have thus far been found sorely wanting.

Over the next few months this blog aims to explore, from the Pleistocene through to the Anthropocene; the diversity of megafauna that have existed on Earth, the impacts they have had on the world around them (ecosystem function) and the contentious issue of the causes of their downfall. Treating the history and development of megafauna as a critical readout for underlying diversity and robustness of ecosystems, I then aim to assess the state that we now find ourselves in, how capable current biota (ourselves included) are of fulfilling the ecosystem roles left vacant by extinct or threatened megafauna, the outlook for the planet in the context of continued megafaunal loss, and what can be done in terms of mitigation.