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Can We Live without Large Herbivores?

In May, 134,000 saiga antelope died in central Kazakhstan. Credit:serg2015/adobe

In May, 134,000 saiga antelope died in central Kazakhstan. Credit: serg2015/adobe

By Thomas Newsome & William Ripple

The collapse of large herbivore populations around the world has dire ecological and social consequences.

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In May this year, 134,000 saiga antelope died in the space of 2 weeks in central Kazakhstan. That was about half the world’s population of this endangered antelope species.

The exact causes of the mass antelope die-off are still unknown, but this alarming event raises the question of whether we can live in a world without large herbivores.

Some 100,000 years ago, during the Pleistocene, we started to lose a suite of herbivores, particularly mega-herbivores larger than 1000 kg. Changes in climate are often invoked as the cause, but overhunting by humans was likely a contributing factor.

During the Pleistocene in Australia, for example, there were iconic species such as Diprotodon, which was the size of a rhinoceros. There were also giant kangaroos that stood up to 3 metres tall. Preying upon these animals was another giant, the marsupial lion. All are now extinct.

The extinction of these creatures can be viewed as a natural experiment that highlights the scale of ecological impacts arising from the loss of large herbivores. The loss of those giant grazers in Australia, in combination with increased fire in the landscape, triggered the replacement of mixed rainforests by sclerophyll forests, which included species more tolerant of drought and fire.

In other areas, such as North America, the extinction of mega-herbivores gave rise to the...

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