Which Continent is Home to the Most Varied Animal Species?


The diversity of the largest animals often depends on the smallest factors.

Scientists have identified over a million animal species, with millions more yet to be discovered across Earth’s seven continents.

But which continent boasts the most animal species?

A History of Cataloging Species

For centuries, scientists have been cataloging and mapping species around the globe.

VĂ­tor Piacentini, an ornithologist at the Federal University of Mato Grosso in Brazil, explained that before the digital age, most information about species distribution came from museum collections.

Today, the public also plays a significant role in this effort.

The Citizen Science Revolution

In the past 20 years, there has been a revolution in citizen science.

Piacentini noted that “scientists are using their data to fill the gaps.”

Mapping Biodiversity

Using this data, scientists map the distribution of species worldwide.

In the late 1980s, scientist Norman Myers coined the term “biodiversity hotspot” for places with an exceptionally high number of species for their area.

Of the 36 hotspots worldwide, most are on continents that cross the equator, where the climate is warm and humid.

The Role of Plants

Barnabas Daru, an applied ecologist at Stanford University, highlighted that plants are the foundation of species diversity.

“If a place has a higher diversity of plants, it makes it easier for other organisms that depend on those plants to become more abundant.”

Plants thrive in warm, humid conditions.

Warm air traps water molecules to create humidity, and warmth helps microorganisms, like decomposers, break down dead material, providing nutrients for plants.

Importance of Insects

Insects, which pollinate many flowering plants, thrive in warmer climates because they can’t regulate their own body temperature.

More insects in the tropics mean more pollination for plants and more food for predators.

Variety of Habitats

Piacentini noted that a continent must offer a variety of habitats to house many species.

Places with high biodiversity have many niches for animals to occupy.

For example, tall trees or high mountains create different environments that allow more creatures to coexist without competing for the same resources.

South America’s Winning Blend

Most scientists agree that South America has the highest number of animal species.

The Amazon rainforest, with its multiple tree layers, and the Andes mountains, with numerous microclimates, provide the perfect combination of heat and diverse geography.

“Everything’s combined there,” Piacentini said, “and that’s why it has the biodiversity [that it does].”

Threats to Biodiversity

However, South America’s biodiversity is under threat from deforestation, mercury mining, and climate change.

Despite these challenges, there’s still an opportunity to mitigate the damage.

“We will certainly lose a lot of species,” Piacentini said, “but every effort that we make to reduce our impact will save us a lot as well.”