(CNN) Birds and mammals will shrink in average size over the next 100 years, with the body mass of the latter falling by a quarter, according to a new study.

The overall body mass of the mammal population has fallen 14% in the last 130,000 years, but research suggests this trend will accelerate massively in the years ahead, according to scientists from the University of Southampton.

Lead study author Rob Cooke explained that human destruction of habitats, hunting, intensive farming, urbanization and global warming are all to blame, and there could be worrying consequences.

"The substantial 'downsizing' of species which we forecast could incur further negative impacts for the long-term sustainability of ecology and evolution," Cooke said in a statement.

Tawny eagles will die out and smaller birds will thrive, say researchers

"This downsizing may be happening due to the effects of ecological change but, ironically, with the loss of species which perform unique functions within our global ecosystem, it could also end up as a driver of change too."

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