wild mammals are struggling


According to a study by scientists at Israel’s Weizmann Institute of Science, the total mass of wild land mammals alive today is less than 10% of the combined weight of humans, with a total of approximately 22 million tonnes. Meanwhile, humanity’s total weight is around 390 million tonnes, and domesticated species and urban rodents add a further 630 million tonnes to the total mass of creatures competing with wild mammals for resources. The biomass of pigs alone is almost twice that of all wild land mammals.

Lead author Ron Milo stated, “These creatures are not doing well at all. Their total mass is around 22m tonnes which is less than 10% of humanity’s combined weight and amounts to only about 6lb of wild land mammal per person. And when you add all our cattle, sheep and other livestock, that adds another 630m tonnes. That is 30 times the total for wild animals. It is staggering. This is a wake-up call to humanity.”

The study, published in Proceedings of the National Academy of Sciences, also revealed that the species that are thriving the most are those that can easily adapt to the presence of humans, such as white-tailed deer and wild boars. Furthermore, common pet species contribute significantly to humanity’s impact on the planet. Domestic dogs weigh approximately 20 million tonnes, which is close to the combined weight of all wild terrestrial mammals, while cats weigh around 2 million tonnes, almost double that of the African savanna elephant.

The depletion of wild mammals appears to be much worse than first anticipated, with the crisis facing the planet’s wildlife requiring urgent assessment.

The next phase of the study will assess how much of the biomass loss occurred over the past 100 years. As the researchers note, “Biomass is complementary to species richness and other diversity metrics, and can serve as an indicator of wild mammals’ abundance and ecological footprint on a global scale.”



At Natural World Fund, we are passionate about stopping the decline in our wildlife.

The declines in our wildlife is shocking and frightening. Without much more support, many of the animals we know and love will continue in their declines towards extinction.

When you help to restore a patch of degraded land through rewilding to forests, meadows, or wetlands, you have a massive impact on the biodiversity at a local level. You give animals a home and food that they otherwise would not have had, and it has a positive snowball effect for the food chain.

We are convinced that this is much better for the UK than growing lots of fast-growing coniferous trees, solely to remove carbon, that don’t actually help our animals to thrive.

This is why we stand for restoring nature in the UK through responsible rewilding. For us, it is the right thing to do. Let’s do what’s right for nature!

Support our work today at https://naturalworldfund.com/ and join in the solution!


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