Ecology: Carnivore declines may be associated with human socioeconomic development

Declines in the populations of the world’s largest carnivores — such as lions, tigers, and wolves — may be more strongly associated with human socioeconomic growth than habitat loss or climate change, suggests a modelling study published in Nature Communications. The findings highlight potential trade-offs between improving the living standards of people and maintaining carnivore populations, which could challenge the achievement of the UN Sustainable Development Goals (SDGs) to promote human development growth.

Previous research has improved our understanding of biodiversity and threats to wildlife populations. However, the drivers of biodiversity change at global scales and the role of human socioeconomic factors (such as improved income, education, and life expectancy) on wildlife populations — including large carnivorous mammals — remain less clear.

Thomas Johnson and colleagues analysed features that drive population declines, and recoveries of 50 species of the world’s largest carnivores — including lions, tigers, and wolves — in over 1,000 populations around the world. The authors found that the leading driver of biodiversity change is changes in human development, and not climate change or habitat loss, as previous studies suggested. They also ran simulations to project how such changes might have shaped carnivore abundances over the past 50 years. The authors found that when human development growth is fast, carnivore populations decline sharply. However, as human development growth slows and begins to plateau, carnivore populations show the capacity for population growth and recovery, potentially revealing strategies that could help address biodiversity loss.

The findings reveal conflicts that could hinder the achievement of the UN SDGs in developing countries, as improvements in health, education and income could negatively affect progress towards improving terrestrial ecosystems. The authors note that more work is needed to establish the mechanisms linking human development growth with carnivore declines.