The diversity of animal species is influenced by many factors, including the smallest ecological elements. Scientists have identified over a million animal species, with millions more yet to be discovered across the seven continents. So, which continent boasts the most animal species?
For centuries, scientists have been cataloging and mapping species globally. Before the digital age, much of this information came from museum collections, says Vítor Piacentini, an ornithologist at the Federal University of Mato Grosso in Brazil. Nowadays, the public also contributes significantly through citizen science. Piacentini notes a “revolution” in citizen science over the past 20 years, with scientists using public data to fill knowledge gaps.
With this information, scientists can map species distribution worldwide. In the late 1980s, scientist Norman Myers coined the term “biodiversity hotspot” to describe regions with an exceptionally high number of species for their area. Of the 36 recognized hotspots, most are on continents crossing the equator, where the climate is warm and humid.
Barnabas Daru, an applied ecologist at Stanford University, explains that high plant diversity supports higher animal diversity. Warm, humid climates are ideal for plants, which in turn support a variety of animals. Warm air traps moisture, benefiting plants and microorganisms that decompose organic matter into nutrients. Insects, crucial for pollination, thrive in these climates, supporting a food chain for many species.
South America, in particular, stands out for its biodiversity. The Amazon rainforest, with its multiple canopy layers, and the Andes mountains, with diverse microclimates, create a variety of habitats. This combination of heat and geographical diversity makes South America the continent with the highest number of animal species.
However, South America’s biodiversity faces threats from deforestation, mercury mining, and climate change. Piacentini warns of potential species loss but emphasizes that efforts to reduce human impact can save many species.
