Africa's first butterfly atlas takes wing

Red Listing
Butterflies belong to Lepidoptera, one of the most diverse and species-rich of the insect orders. Importantly, the atlas offers a detailed conservation assessment and Red Listing of all the sub-continent's butterflies, not only for threatened species but also for those species not currently threatened. As such, it will guide government, municipalities, landowners and others on the steps that need to be taken to conserve the region's butterfly populations. The atlas is a sweep of information on butterflies, both in the wild and from specimens in private, institutional and museum collections, such as those at London's Natural History Museum and the African Butterfly Research Institute in Kenya.

Mapping it
For the first time, grid-referenced distribution maps are presented for all the region's butterflies - 794 species and subspecies in total, including 657 distinct species. Launched under the umbrella of the Southern African Butterfly Conservation Assessment (SABCA), the atlas is an alliance between UCT's Animal Demography Unit (ADU), where the project management was based; the South African National Biodiversity Institute (SANBI), which provided core funding for the project; and the Lepidopterists' Society of Africa (LepSoc), which co-ordinated and sponsored the field surveys and provided much butterfly expertise. It's the first insect project that SANBI has funded. The ADU is an old hand at running atlas projects, having produced bird (1997) and frog (2004) and reptile atlases (the latter of which is due to be published later this year). Project co-ordinator and alumna Dr Silvia Mecenero, who describes herself as a conservation ecologist, has a long association with the ADU. While a PhD student in the unit in 2001, she infiltrated three breeding colonies of the Cape fur seal in Namibia. For two years she collected and dissected seal scats; the fishy debris yielded information on seal diet, useful in tracking fish populations for fisheries, and for managing the country's valuable horse mackerel resource. "Sorting out, counting and measuring thousands of little fish ear-bones from the scats was blinding work," Mecenero recalls from the ADU in the new Department of Biological Sciences, the product of a merger between Zoology and Botany in 2012.

Orchestrated effort
One of the project's triumphs was the response from citizen scientists. Butterflies are relatively easy to see and identify, even for non-specialists. At the time, citizen scientists yielded over 17 000 photographic records for the project's online virtual museum. LepSoc has continued with the virtual museum, and it now hosts over 30 000 photographic records. Also, as part of SABCA, the first Butterfly Census Week was launched, for public monitoring of butterfly populations. (This bi-annual event is now managed by LepSoc, and the 7th census was held a couple of weeks ago.) "It's been a huge boost to public awareness," says Mecenero.

Conservation threats
While butterflies may seem just the pretty subjects of little girls' dreams, they're also the flagship species for insect conservation. Insects are the most species-rich group of animals, and their vital role in ecosystems - especially those that are insect pollinators - now underpins their conservation status. Naturally, the atlas has a strong conservation message. 151 species and sub-species - one fifth of Southern Africa's butterflies - are of conservation concern, and 8% are threatened with extinction. The most threatened are right under our noses in the Cape fynbos - as well as in the KwaZulu-Natal midlands grassland biome. Fifty per cent of the butterflies listed are endemic, which means they are found only in the atlas region and nowhere else. Sixty species are threatened with extinction, with 14 considered critically endangered, 27 endangered and 19 vulnerable. Three of the critically endangered species are possibly extinct. Until recently, that number was thought to be four - the Waterberg Copper (Eriksonia edgei) of the Waterberg in Limpopo has been considered extinct for more than 20 years. But in March this year it was rediscovered in another locality, by Lepsoc's Professor Mark Williams. Researchers are working on a conservation plan for the new locality in a private nature reserve in the Waterberg. Habitat is vital to butterfly conservation. Many occur in small, limited areas because they are usually associated with specific host plants and host ants that are needed to complete their life cycle. The atlas also comes with useful habitat information that flags conservation concerns. For example, some butterflies, such as the Lycaenids, occur only in a tiny area the size of a rugby field. "If a species occurs in a small area, we flag it for conservation if the area is currently threatened, or in case a threat arises," says Mecenero.

Alien vegetation
Most habitat loss and degradation are due to forestry, agriculture, mining and housing, inappropriate fire regimes, and alien vegetation that is replacing indigenous plants. In the Western Cape, rapid land development poses a significant threat. "Unless South Africa pays careful attention to the conservation of our butterflies now, we could lose many more of these fascinating creatures - and the important services they provide to our ecosystems," warns Mecenero. But indirectly, the atlas is also about other creatures bright and beautiful. "We're identifying butterfly hotspots to see how they overlap with bird areas and nature conservation areas." The project forms the backbone of Mecenero's postdoctoral fellowship, through the University of Pretoria. With the atlas done and dusted, she's clearly chuffed. Much like a conductor, she's led a large and variegated ensemble - ecologists, lepidopterists and Joe Public - through numerous rewrites, edits and revisions. "It's been the best job ever. I've loved it." Looking ahead, she wants to expand the atlas into sub-Saharan Africa, digitise all the collections, and expand the virtual museum. But this will depend on funding. There are also gaps in the records, particularly in the Free State, Northern Cape and Lesotho, more out of reach than other areas to citizen scientists and the coterie of butterfly experts and enthusiasts who have brought this valuable work to fruition.

(For more information: vmus.adu.org.za; census information on LepSoc website) (Helen Swingler)

Fast facts from the Butterfly Atlas

• South Africa is home to 17% of Africa's 4 000 butterfly species.
• French researchers estimate the yearly value of insect pollinators such as butterflies to be some €153 billion.
• While butterflies may not contribute as much as bees, they perform unique pollination functions. Aeropetes tulbaghia is the only known pollinator of several plants with red flowers, such as Disa uniflora, the red Disa orchid.
• Some eight per cent of Southern Africa's butterflies are threatened with extinction. The most threatened are right under our noses in the Cape fynbos - and in the KwaZulu-Natal midlands grassland biome.
• 151 species and sub-species - one fifth of Southern Africa's butterflies - are of conservation concern.
• Fifty per cent of the butterflies listed are endemic, found only in the atlas region.
• Sixty species are threatened with extinction, with 14 considered critically endangered, 27 endangered and 19 vulnerable.
• Three critically endangered species are possibly extinct. Until March this year, when the Waterberg Copper (Eriksonia edgei) was rediscovered in the Waterberg after more than 20 years, that number was thought to have been four.

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