By Marcus Lu
Mammals, though comprising a small fraction of Earth’s creatures, hold vital ecological roles globally. They are crucial for maintaining ecosystem health through services like pollination, seed dispersal, and predator-prey dynamics.
In this visualization, we depict the average lifespans of mammals, using data from Discover Wildlife and the United Nations.
Human Lifespans on the Rise
Defined as warm-blooded creatures with hair or fur, mammals nurse their young with milk from mammary glands. While smaller animals such as weasels typically live 1-2 years, larger counterparts like elephants can thrive for decades, and bowhead whales can live for 200 years, or even longer.
| Animal | Average lifespan (years) |
|---|---|
| Weasel | 1 to 2 |
| Hedgehog | 3 |
| Wolverine | 12 |
| Tiger | 14 |
| Brown bear | 25 |
| Lowland tapir | 30 |
| Western gorilla | 35 |
| Brandt’s bat | 41 |
| Humans (1950) | 47 |
| Elephant | 56 |
| Humans (2022) | 72 |
| Bowhead whale | 200 |
Notably, human lifespans have experienced a remarkable surge. According to the UN Population Division, the global average life expectancy has surged from 47 years in 1950 to 72 years in 2022, marking a 25-year increase. This is attributed to advancements in nutrition, medication, and essential resources.
However, as human longevity flourishes, it can have an adverse effect on wildlife mammal populations. To put this into numbers, over the past 100,000 years, the surge in human population has precipitated an 85% reduction in wild mammal biomass.
Today, livestock dominates 62% of the world’s mammal biomass, with humans accounting for 34%, while wild mammals comprise only 4%.
Despite a decline in mammal diversity, the total biomass of terrestrial mammals has significantly increased, expanding approximately ninefold over the past 10,000 years.
Curious to learn more about mammals? Check out this graphic that shows the biomass of all the world’s mammals.
