Prior to the 20th century, some experts estimate there were more than 100,000 tigers living in the wild; today that number is between 3000 -- 4000. At the same, over the last 150 years, the human population of Asia as grown from 790 million to over 4 billion, with dire consequences for tigers and other wildlife.

But these trends are changing. The demographic transition is the process by which human populations peak and then go down. The researchers looked at different scenarios of economic, education, migration, and urbanization policy. In 2010, 57 million people lived in areas defined as "tiger conservation landscapes" that contained all of the world's remaining wild tigers. However, by 2100, depending on population trends, as few as 40 million people could be sharing space with tigers, or it could be as many as 106 million.

Different population scenarios depend on the course of the demographic transition. Over the long-term, the scenarios associated with the lowest human populations are also associated with the greatest levels of urbanization and education. At the same time, urban consumption is the source of many of the threats to tigers. Therefore, the authors say conservation authorities must engage with people in cities to save tigers, while continuing to support site-level protection efforts around tiger source sites.

Said lead author Eric Sanderson, Senior Conservation Ecologist with WCS: "Urbanization and the subsequent human demographic transition is arguably the most important historical trend shaping the future of conservation. How that transition plays out is not pre-determined. Rather it depends on the policy decisions that governments, and the societies they represent, take with respect to fundamental matters such as urban governance, education, economic reform, and the movement of people and trade goods. These decisions matter for us and tigers too."

合著者和WCS Fi的高级副总裁说eld Conservation Joe Walston: "If we want a world with tigers, forests, and wildness to persist beyond the 21st century, conservation needs to join forces with groups working to alleviate poverty, enhance education for girls, reduce meat consumption, and build sustainable cities."

巴鲁克坳的作者布莱恩·琼斯教授说lege: "Demographic futures, and the socioeconomic causes and consequences thereof, are notoriously difficult to predict. As such, biophysical futures are similarly fraught with uncertainty. Understanding the consequences of different pathways, driven in large part by policy decisions, is crucial to developing a conservation strategy to protect the planets most endangered habitats. Our ability to understand the future will depend in part on how well we understand urbanization, in terms of both land use and demographic behavior."

The paper builds on a 2018 WCS study that found that the enormous trends toward population stabilization, poverty alleviation, and urbanization are rewriting the future of biodiversity conservation in the 21st century, offering new hope for the world's wildlife and wild places.