A new study is now suggesting that mammals and birds will shrink in size over the next 100 years or so.

According to the study ‘Nature Communications’, 

“Ecological downsizing can entail the loss of unique ecological functions and can impact ecosystem structure, function, and bio-geochemical cycles. Hence, downsizing could be a driver, as well as a consequence, of global change with implications for the long-term sustainability of ecological and evolutionary processes.

They also concluded that the recent human activities have triggered the rate of extinction in animals and have increased the capability to alter the structure of mammals and birds on Earth. This will lead to grave ecological consequences.

African elephants are now born tuskless because they have been consistently targeted for the best ivory. They have developed this trait to ensure their survival in a world where they are killed for ivory.

The study adds that the total body mass of the mammals will significantly reduce by as much as 25% in the coming 10 years. The difference is way more than the 14% body size reduction mammals went through from 130,000 years ago. 

The study was conducted in regard to the body mass, litter size, diet, habitat and the length in time between generations in 15,484 birds and land mammals.

The study also mentioned which species will go extinct according to the International Union for Conservation of Nature (IUCN) Red List of Threatened Species.

Critically-endangered species stand a chance of 1% survival rate while endangered animals have a two in three rate of survival. Vulnerable animal species are the safest with a 90 percent survival rate. 

Rob Cooke, the study’s lead author said,

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, urbanization and the effects of global warming.

The study’s findings also conclude that smaller, more fertile and adaptable species have a higher chance of surviving in comparison to their larger counterparts.

Do we really need more damage to take place before we realise we’ve destroyed our planet?