Most Biodiverse Countries: Brazil, Indonesia and Colombia Lead

Brazil, Indonesia and Colombia are the countries with the most biodiversity. On the Global Biodiversity Index published by The Swiftest in 2022, Brazil scores 512.34, Indonesia 418.78 and Colombia 369.76. The index combines each country’s known species of birds, amphibians, fish, mammals, reptiles and vascular plants. Brazil leads on the strength of 34,387 vascular plants and 1,141 amphibians. Indonesia has 729 mammals, the most of any country in the top 20. Colombia has 1,863 bird species. China, Mexico, Australia, Peru, India, Ecuador and the United States complete the top ten. Some of these are expected and some are not. A few countries famous for wildlife, above all Madagascar, do not make the top 20 at all.

Brazil 512, Indonesia 419, Colombia 370: the 2022 top ten

The list below is The Swiftest’s ranking as reproduced in Wikipedia’s article on megadiverse countries. It counts species, not how unusual they are. That one design choice explains most of the surprises further down: a big country with many habitats can build a huge total even if few of its species are found nowhere else.

The first three places are no surprise. Brazil holds the largest share of the Amazon rainforest, which is often described as having the greatest biological diversity in the world. Wikipedia’s Brazil article also singles out the Atlantic Forest and the Cerrado savanna for their biodiversity, and the country holds the Pantanal wetland in the Center-West. Its lead of more than 90 points over Indonesia is the largest gap between any two neighbours in the table. Brazil’s totals are not only high but broad: it has 4,738 fish, 847 reptiles and 693 mammals. Indonesia’s 4,813 fish species reflect its place in the Coral Triangle, the region of tropical sea shared with Malaysia, the Philippines, Papua New Guinea, the Solomon Islands and Timor-Leste, where each ecoregion holds at least 500 species of reef-building coral. Colombia has coasts on both the Caribbean and the Pacific, and runs from those coasts over the Andes to the Amazon basin. That spread of habitats in one country is what produces its world-leading bird count.

Mexico, Peru, India and Ecuador, in fifth, seventh, eighth and ninth, are also where most people would expect them. Mexico is where North and Central American wildlife meet, and it has 988 reptile species, second only to Australia. Peru has 1,861 bird species, just two fewer than Colombia, and nearly 20,000 vascular plants on the slopes of the Andes and in the Amazon lowlands. India combines the Himalaya, the Western Ghats and the forests of the northeast, and has 19,635 vascular plants, 1,212 birds and 2,601 fish. Ecuador scores 291.58 even though it is by far the smallest of the four, with 1,629 bird species and 659 amphibians.

China at four, Australia at six and the United States at ten

Three countries in the top ten are not usually pictured as rainforest nations, and each gets there by a different route.

China is fourth, less than four points behind Colombia. Its strength is plants: 31,362 vascular plant species, second only to Brazil among the top 20. It also has 3,476 fish species and 622 mammals. China covers a very wide range of climates, from the tropical south to the high Tibetan Plateau and the dry north. On an index that counts species, that range adds up.

Australia is sixth, although most of it is desert or dry scrub. It wins two whole categories in the top 20. It has 1,131 reptile species, more than any other country listed, and ahead of Mexico’s 988. It also has 4,992 fish species, just ahead of Indonesia’s 4,813. Australia has only 725 bird species and 245 amphibians. Its dry interior suits reptiles far better than it suits frogs, and the scores reflect that.

The United States is tenth, scoring 280.13 with 15,500 vascular plants and 3,081 fish species. That fish total is the fifth-highest in the top 20. The country is one of the 17 megadiverse countries named by Conservation International in 1998, and much of its score comes from temperate forests, deserts and coasts rather than rainforest. It has only 844 bird species and 326 amphibians, fewer than Ecuador, a country less than a thirtieth of its size.

Venezuela, Myanmar, Vietnam, Tanzania, Bolivia: the unexpected names from 11 to 20

Conservation International’s 1998 list of 17 megadiverse countries is still the most-cited shortlist. To qualify, a country needed at least 5,000 endemic plant species and a coastline. Positions 11 to 20 of the 2022 index include several countries that were never on it.

• Venezuela (11th, 273.39) has about 30,000 vascular plants, the third-highest plant count in the top 20, after Brazil and China. It misses the top ten because its fish, mammal and reptile totals are more modest. Many of its plants grow on the tepuis of the Guayana Highlands, flat-topped sandstone mountains whose summits are cut off from the forest below.
• Myanmar (13th, 221.77) is not a megadiverse country, but it has 1,034 birds and 16,000 vascular plants.
• Vietnam (14th, 216.97) has 2,423 fish species, more than Peru or Ecuador.
• Tanzania (17th, 213.10) has 1,074 bird species, the most of any African country on the list after the Democratic Republic of the Congo’s 1,110.
• Bolivia (18th, 209.55) is landlocked, so it could never meet the 1998 coastline rule. Even so, its 1,435 bird species put it ahead of Venezuela.
• Thailand (20th, 200.77) closes the top 20, with 2,150 fish species but only 6,600 vascular plants.

Four megadiverse countries do make positions 11 to 20: Papua New Guinea (12th), Malaysia (15th), the Democratic Republic of the Congo (16th) and South Africa (19th). South Africa scores 207.94 with 21,250 vascular plants. That is more plants than six countries in the top ten, yet it only just makes the top 20, because its bird and amphibian totals are low.

Madagascar and the Philippines: megadiverse, but outside the top 20

The two biggest near-misses are both island nations on Conservation International’s 1998 list, and both miss for the same reason. The index rewards how many species a country has, not how many are found only there.

Madagascar has been isolated for roughly 90 million years, since it split from the Indian landmass. About 90 percent of all its plant and animal species are found nowhere else. It has 14,883 plant species, more than 80 percent of them endemic, including six baobab species found only there. It has more than 100 species and subspecies of lemur and two-thirds of the world’s chameleon species. But it has only just over 300 bird species, about a sixth of Colombia’s, and it had no room in the top 20. On a ranking of endemism, Madagascar would be near the top. On a ranking of totals, it is not in the top 20.

The Philippines has 714 bird species, 243 of them endemic, which is the third-highest number of endemic birds of any country, after the much larger Australia and Indonesia. Its seas are sometimes described as the richest in marine life in the world, and 16 new mammal species were discovered there in a single decade. Its land area is small, though, and its totals of plants and freshwater fish cannot match those of continental countries.

The same arithmetic keeps out small countries with a lot of wildlife. Costa Rica covers about 51,180 km², slightly less than Bosnia and Herzegovina, and cannot reach Brazil-sized totals. Ecuador shows the other side: at ninth place it is the smallest country in the top ten, and it has the most biodiversity per square kilometre of any nation.

Colombia’s 1,863 birds against Peru’s 1,861: where the category leaders differ

A single index score hides the fact that no one country leads in everything. Among the top 20:

• Birds: Colombia 1,863, Peru 1,861, Brazil 1,816. First and second place are separated by two species, so a few new records from Peru could change the order.
• Vascular plants: Brazil 34,387, China 31,362, Venezuela about 30,000.
• Amphibians: Brazil 1,141, Colombia 812, Ecuador 659.
• Mammals: Indonesia 729, Brazil 693, China 622.
• Reptiles: Australia 1,131, Mexico 988, Brazil 847.
• Fish: Australia 4,992, Indonesia 4,813, Brazil 4,738.

Brazil appears in the top three of all six categories, and that consistency is what gives it a clear lead in the index. Colombia wins only the birds but places well everywhere else. Australia wins two categories but falls far behind in birds and amphibians, which holds it at sixth. The bigger picture is that the tropics of the Americas and Southeast Asia dominate, and that big countries collect more species than small ones, even very rich small ones. For the 1998 shortlist in full, see our guide to the 17 megadiverse countries. What the word means is covered in what biodiversity is, and Madagascar’s near-miss makes more sense after reading about its lemurs and other island wildlife.