Lessons of 15,000 Years of Human–Wildlife Interaction for Conservation in Patagonia in the 21st Century

Andrés J Novaro,Rebecca Susan Walker

doi:10.3390/d13120633

Abstract

Humans arrived in the Patagonia region of southern South America in the late Pleistocene period, ca. 15,000 years ago. A few centuries later, during a period of rapid warming, the megafauna went extinct in Patagonia, as well as some smaller species, like the guanaco (Lama guanicoe), in the southern portion of the region. As in other regions, extinctions probably occurred due to a combination of effects of climate and direct and indirect impacts of humans on wildlife communities. We reviewed recent archeological and genetic-based discoveries about numbers and distributions of humans and wildlife and their early interactions and used them to draw lessons for current debates among managers and scientists. Recent discoveries, for example, help us understand (1) the population limitation mechanisms and other interactions involving guanacos, livestock, forage, predators, and scavengers; (2) the magnitude of wildlife movements and the need for landscape-level planning for conservation; (3) the importance of indirect effects of human activities on wildlife communities; and (4) the compounded effects of human activities and climate change on wildlife. We believe these lessons drawn from deep time and recent history can help define new priorities for research and management and inform our conservation vision for the 21st century, a period when dramatic climate change impacts will add challenges to a region subject to a century of overgrazing and other anthropogenic pressures.

Highlights

For millions of years, geological and evolutionary forces, such as the breaking up of Gondwanaland, the rising of the Andes mountains, and the emergence of the Panamanian land bridge, together with changes in climate, governed the evolution of life on the SouthAmerican continent and the development of faunal communities
Examples of key paleoecological insights for conservation planning include understanding how bottom-up processes of climate change can be distinguished from top-down processes, including anthropogenic impacts on biodiversity [8,9], long-term biotic responses that depend on complex and non-linear processes with thresholds and feedbacks that lead to unexpected surprises, and the effects of global warming in the late Pleistocene era at similar rates and magnitudes to the warming projected for the 21st century [7]
Humans represented a new predator in the Patagonian ecosystem in the late Pleistocene period, capable of hunting even the largest-bodied herbivores [18]

Summary

Introduction

Geological and evolutionary forces, such as the breaking up of Gondwanaland, the rising of the Andes mountains, and the emergence of the Panamanian land bridge, together with changes in climate, governed the evolution of life on the South. The last continental region to be colonized by Homo sapiens, recent analyses of radiocarbon dates from archeological sites and mtDNA from ancient and living people have estimated an arrival in Patagonia between 14,500 and 17,000 years ago, very quickly after reaching the continent [1,20] Humans represented a new predator in the Patagonian ecosystem in the late Pleistocene period, capable of hunting even the largest-bodied herbivores [18] They appeared to have relied more on the smaller and more abundant guanacos and the even smaller camelid, Lama gracilis, than on megafauna [29]. Some iconic wildlife species, such as Andean condors, rheas, and Andean cats (Leopardus jacobita), have not recovered or have continued their declines in abundance and/or distribution, and the causes for these trends are not well understood [42,47,53]

Lesson 1

Lesson 2

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Lesson 4

Findings

Rewilding versus Coexistence or Inclusive Rewilding?