A new study revealed that the average animal size will be reduced by 25% over the next century due to humans’ destruction of the habitat of larger creatures and unless strict measures are taken to protect wildlife.

Researchers at the University of Southampton warned that smaller and adaptable creatures like rodents, dwarf gerbils and songbirds are expected to prevail, while larger, less adaptable, slow-lived species, like tawny eagles and rhinos, will likely become extinct.

Small, highly-fertile insect-eating animals that can flourish in a variety of habitats will be the most resilient, the study indicated.

“By far the biggest threat to birds and mammals is humankind – with habitats being destroyed due to our impact on the planet, such as deforestation, hunting, intensive farming, urbanisation and the effects of global warming," lead author of the study published in the journal Nature Communications, Rob Cooke, said.

“The substantial ‘downsizing’ of species which we forecast could incur further negative impacts for the long-term sustainability of ecology and evolution. 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,” he added.

“We have demonstrated that the projected loss of mammals and birds will not be ecologically random – rather a selective process where certain creatures will be filtered out, depending on their traits and vulnerability to ecological change," a professor at the University of Southampton, Felix Eigenbrod, deplored.

“Extinctions were previously viewed as tragic, deterministic inevitabilities, but they can also be seen as opportunities for targeted conservation actions. As long as a species that is projected to become extinct persists, there is time for conservation action and we hope research such as ours can help guide this,” research chair at Memorial University in Canada, Amanda Bates, noted.