Cape Town - Africa is for the birds, right? Absolutely, according to a new analysis by a group of bird specialists and scientists that throws up some interesting – and welcome – results.
Their findings were published in the latest issue of the South African Journal of Science. It could help boost bird-based ecotourism – dubbed “avitourism” – on the continent.
According to some sources, avitourism is one of the fastest-growing outdoor activities in the world. Ecotourism hot spot Costa Rica generates almost half of its tourism income from birders, while the Department of Trade and Industry has reported that avitourism is worth more than $200 million (more than R2-billion) to the South African economy.
One of the authors of the paper, Newlands-based birding specialist Dr Chris Lotz, explains that the common perception in the international birding community is that South America is the world’s best birding destination, and that Africa doesn’t compete with it in terms of bird diversity.
“We’re trying to show that if you look at a deeper level (than just counting species), sub-Saharan Africa has by far a genetically more diverse birdlife than the rest of the world,” he says.
Of course, many birders keep life-lists and like to “tick” as many new species as possible.
Using just this simple criterion, South America does still come out tops. According to the world’s bird database, Avibase, that is supported by conservation group Birdlife International, there are about 10 000 bird species and 22 000 sub-species world-wide – and South American countries Colombia and Peru have the highest number of species, with 1 816 and 1 752 respectively.
But species alone do not represent full biological diversity.
Taxonomists classify all life forms according to a ranking system that includes the increasingly specialised kinship groupings of class, order, family and genus, ending in species and sub-species.
Birds belong to the class Aves that includes all feathered, winged, bipedal, warm-blooded, egg-laying, vertebrate animals.
And the order Coraciiforms, for example, is made up of 10 families of birds that include the kingfishers, todies, motmots, bee-eaters, rollers, hoopoes and hornbills.
If a birder looks beyond just ticking individual species, says Lotz, he or she will find that a region with – say – eight species from eight genera is more diverse than a region with eight species, but from only seven genera. And this is where sub-Saharan Africa comes into its own.
Lotz worked with Professor Michael Cherry of Stellenbosch University’s Department of Botany and Zoology, and birding enthusiasts Monika Forner and Dr John A Caddick to prove their point. “We took eight areas in Africa that are similar in size, and compared them with 16 similar regions spread across the world,” he says.
“For 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.”
Using regression analyses (a statistical process for estimating the relationships among variables), they tested for relationships between genus count, family count, order count, and the ratios between, for example, species-genus or species-family.
They found that the high number of species in Colombia and Peru were distributed in a surprisingly small number of families – 85 and 87 respectively.
Comparison on a higher taxonomic level showed that northern India had the world’s largest number of families at 104, but sub-Saharan Africa was only just “behind”, boasting 103 families in three regions, and between 97 and 101 families in all its other regions.
And moving even higher up the taxonomic ranks to the level of order, sub-Saharan Africa comes out top: the Mozambique-Zimbabwe region has the highest number of different orders of birds on the planet at 30, while there are 29 different orders in the coastal West Africa, South Africa, Ethiopia-Eritrea and Angola regions.
The authors note that no other continent contains regions with more than 28 orders.
“In terms of higher taxonomy, sub-Saharan Africa is arguably the richest part of the planet for birds,” they argue. And even at species level, parts of sub-Saharan Africa are still very bird-diverse: one part of East Africa, the same size as Colombia, has 1 324 species.
Their findings hold significant implications for conservation efforts. “There are eight endemic bird species in Malawi’s Nyika National Park. They are distributed in seven genera, all of which are very widespread in Africa,” says Lotz.
“But the eight species in Madagascar’s Mikea Forest are in eight genera, one of which is found in no other (proclaimed) Important Birding Area (IBA), and three of which are confined to the South Malagasy spiny forests’ Endemic Bird Area (EBA).
“The Mikea Forest should therefore be afforded a higher conservation priority,” he argues.
The Important Birding Area Programme is an initiative of BirdLife International, and aims to conserve a network of sites critical for the long-term survival of threatened bird species.
“We recommend counting at all taxonomic levels in existing IBAs and EBAs as a first step in assessing how priorities might be affected,” the authors conclude. - Sunday Argus