Sub-Saharan Africa has greater bird diversity than anywhere else in the world.
The research, titled Beyond Just Species: Is Africa the Most Taxonomically Diverse Bird Continent? published in the South African Journal of Science, is surprising, given that South America, not Africa, is considered the utopia of bird diversity.
"We took eight areas in Africa that are similar in size and compared them with 16 similar regions spread across the world," said Dr Chris Lotz, who received his PhD from the University of Cape Town and who worked with Stellenbosch University's Professor Michael Cherry.
"In each region, we downloaded bird lists from the world bird database, Avibase, and then counted the number of species, genera, families and orders for each region."
Avibase is an online database with more than ninemillion records- about 10000 bird species. It is supported by Birdlife International, a global alliance of conservation groups.
In taxonomy – the scientific classification of organisms – organisms are separated into kingdoms, then phylum, class, order, family, genus and finally species. There are six kingdoms in total, but millions of species.
Taxonomy is often described as being like a tree, with kingdoms being the thickest branches that split and divide into twig-like species.
For example, a domestic cat is part of the animalia (kingdom), chordate (phylum), mammalia (class), carnivore (order), felidae (family) and felis (genus). In scientific circles, your darling Fluffy is called Felis catus.
The analysis of Lotz and Cherry, who are in the department of botany and zoology at Stellenbosch University, found that, although South American countries, namely Colombia and Brazil, had the highest number of species at 1816 and 1752 respectively, northern India had the highest number of families, but sub-Saharan Africa had the highest number of orders.
"There are 29 different orders of bird in coastal West Africa, South Africa, Ethiopia-Eritrea and Angola, while Mozambique-Zimbabwe has the highest number of orders on the planet at 30," the university said.
No other continent contains regions with more than 28 orders, it said.
"In terms of higher taxonomy [the categories above species], sub-Saharan Africa is arguably the richest part of the planet for birds," the authors write.
However, part of East Africa – about the size of Colombia – had 1324 species, showing that it had high diversity at species level as well, Lotz said.
Peter Ryan, the acting director of the University of Cape Town's Percy FitzPatrick Insititute of African Ornithology, said that the study reinforced findings published in the scientific journal Nature last year.
A paper titled The Global Diversity of Birds in Space and Time, found that the "high diversity [of bird species] in South America is a new phenomenon, like fynbos, which became the dominant vegetation in the Western Cape in the past four million years", he said.
"In terms of phylogenic diversity, rather than species, Africa and Australia are more important. It's about the level of biodiversity you're interested in conserving," Ryan said.
The two studies "independently came to the same conclusions".