endemism gone wild The forgotten islands of São Tomé and Príncipe

Text by Martim Melo & Peter Ryan

From the peak of São Tomé on a rare clear day, you can see the entire island below you: precipitous ridges clothed in primary forest, with agricultural land beyond. You can make out the routes taken by intrepid 19th- century naturalists and the places where you have wandered for days, lost in the constant rain. From within, the forest appears infinite, but from above it seems so small. It is almost inconceivable that this tiny area could support 20 endemic bird .

alexandre vaz august thomasson

Relative to their size, São Tomé and Príncipe are the islands with the greatest number of endemic globally alexandre vaz

Above The imposing dome of Boné de slands are special places for natural- number of endemic birds globally, with 17 from the Mandara Mountains (along the iven their remarkable number Jóquei (Jockey’s Cap) set against a turgid ists. Their isolation allows unique species confined to São Tomé (857 square Nigeria/Cameroon border) and includes of endemics, São Tomé and tropical sky. The oil palms that cover the species to evolve, often including kilometres in extent), eight restricted to Mount Cameroon. São Tomé, Príncipe and Príncipe rank high on any Af­ lower slopes of this small islet off the coast ‘strange’ creatures that are adapted to Príncipe (139 square kilometres) and three Annobón are oceanic islands that have rican birder’s must-visit list. Ly- Nigeria of Príncipe produce unusually large fruits, islandI life. These peculiarities contributed shared between the two. By comparison, never been connected to the mainland ingG close to the equator, the islands were which are the main food of an endemic significantly to Darwin and Wallace’s un- the Galápagos islands have 22 endemics or to each other, being separated by seas covered in dense rainforest when they were ▲ Mt Cameroon form of Príncipe Seedeater. derstanding of evolution, inspired by the in a land area almost 10 times greater. more than 1 800 metres deep. Although discovered by the Portuguese in the 15th Galápagos and the islands of South-East Only the Hawaiian islands, 20 times larger, Annobón is the smallest (17 square kilo- century. All the endemic birds evolved in Bioko cameroon Opposite The São Tomé Oriole is just one Asia respectively. São Tomé and Príncipe, support more endemic birds (30 extant metres) and most isolated island, it still these forests. Extensive areas of the islands Atlantic of 20 endemic species confined to the forests two small islands 200 kilometres off the species, plus 19 extinctions in historical supports two endemic bird species, a white- have since been modified by agriculture, Ocean of São Tomé. Like many island birds, it is less coast of Gabon, are equally fas­cinating. times). The Democratic Republic of São eye and a paradise flycatcher. Bioko is the but the rugged terrain has meant that size- brightly coloured than its mainland counter­ The biota of these former Portuguese col­ Tomé and Príncipe is the second smallest largest island (2 027 square kilometres) in able tracts of primary forest have been Príncipe equatorial parts; this is a female and so is particularly drab. onies is so distinct that their forests consti- country in Africa (after the Seychelles), yet the group, yet it has only two endemics (a preserved. Entering these forests is like guinea tute an independent eco-region. Birds are ranks fourth in terms of the number of en- white-eye and a batis) because it was con- stepping into a new world; with a few ex- Gulf of Guinea Previous spread A magnificent male São the most visible component of the unique demic birds. It’s not surprising that each nected to Africa during the last glaciation, ceptions (several African bird species have São Tomé Tomé Paradise Flycatcher glares at the camera species composition and are recognised as island is recognised as a separate Endemic some 11 000 years ago. The four islands been introduced), all the birds encountered after being caught in a mist net. Depicted in important ambassadors for the conserva- Bird Area by BirdLife International. may be quite old, having formed some five here occur nowhere else. In addition to this field guides as a rather drab black flycatcher, tion of the remaining forest, appearing on Together with Bioko and Annobón to 30 million years ago, but genetic studies astonishing endemism, more than 80 per Gabon it is amazingly iridescent. And unlike many of the island nation’s coat of arms, stamps (which belong to Equatorial Guinea), São suggest that their 32 endemic bird species cent of the land snails are endemic, as are Annobón the São Tomé endemics, it is not restricted to and currency. Tomé and Príncipe form the Gulf of Guinea are the result of recent speciation events eight reptiles and seven amphibians (which primary forest, but is also found in secondary Relative to their size, São Tomé and islands group, part of a 1 600-kilometre rather than being relict species that went is amazing, given their intolerance of salt growth and farm bush. Príncipe are the islands with the greatest line of volcanoes that extends south-west extinct on the mainland. water). Mammals are well represented

34 São Tomé and Príncipe AFRICA – BIRDS & BIRDING april/may 2012 São Tomé and Príncipe 35 Mount Cameroon The demise of Speirops Speirops Parallel evolution in Gulf of Guinea

white-eyes Bioko Speirops

he white-eyes (family Zosteropidae) make up a small, homo­ Tgenous group allied to the babblers and sylvid warblers. With many island forms, the species-level is somewhat con- tentious, but the Handbook of the Birds of the World recognises 98 species in 14 genera. Of these, 74 species are placed in Zoster- Forest White-eye ops, making it the largest bird . Only two genera are represented in Africa: some 22 species of Zosterops occur throughout sub-Saharan Africa and adjacent is- lands, and four species of Speirops are confined to a line of volca- noes extending from Mount Cameroon into the Gulf of Guinea. Montane White-eye Speirops are larger than typical white-eyes, have stout bills and lack green or yellow coloration in their plumage. The ranges of the four species do not overlap, with one species occurring on Mount Cameroon and one on each of the three large islands in the Gulf of Guinea: Bioko, Príncipe and São Tomé. Traditionally, the São Tomé Speirops is considered to be closely allied to the Mount Cameroon Speirops and it has been argued African Yellow that the genus evolved on São Tomé, radiating from there to White-eye the adjacent islands and Mount Cameroon. However, recent research by Martim Melo and his colleagues turns these ideas upside down (Molecular Ecology 20: 4953–4967). Evidence from several genetic markers shows that speirops do not constitute a Príncipe White-eye natural group, with the continental forms on Mount Cameroon and Bioko closer to the Forest and Montane white-eyes, whereas alexandre vaz the Príncipe and São Tomé speirops make up part of a radiation one of the more striking aspects of birding on the of white-eyes on the oceanic islands in the Gulf of Guinea that is linked to the African Yellow White-eye (see figure). islands is what is missing; there are no hornbills, This might seem unlikely, given the similarity in structure within Annobón White-eye Speirops. However, the four species of Speirops differ consider- woodpeckers, barbets, robins or bulbuls ably from each other (for example, some have eye-rings and others don’t), and their defining character is more one of dif- by bats, including diurnal species that have on islands, whereas large species are ference from the typical white-eyes. They provide yet another evolved in the absence of forest raptors. constrained by the limited space avail- ex­ample of parallel evolution, whereby the same morphological São Tomé White-eye Each island also has a shrew, although it is able. There have also been two adaptive traits evolve independently when organisms face similar envir­ hard to imagine how these small , radiations which until recently have been onments. It remains to be explained quite what has driven the which need to feed every few hours, man- overlooked: one features the islands’ parallel evolution in this case. However, all four species co-occur aged to colonise the islands. Plant variety white-eyes (see opposite), the other the with a typical white-eye, and they characteristically are more is also impressive, with some 200 endemic Príncipe Seedeater and its large cousin, the abundant than their smaller relatives. nik borrow flowering plants and the highest diversity São Tomé Grosbeak. The Gulf of Guinea white-eyes join a select group of island São Tomé Speirops Top Trees grow straight and true in the few of ferns in Africa. The São Tomé Oriole has lost most of its birds that have undergone adaptive radiation (others are Darwin’s remaining tracts of primary forest on São Although the endemic birds have relatives’ yellow pigment, lending support finches, Hawaiian honeycreepers, Madagascar’s vangas and, at a Tomé. Fortunately for birders, there are few evolved quite recently, they include many to the hypothesis that sexual selection is much smaller scale, Tristan da Cunha’s finches). In terms of phylo­ species confined to the distant canopy. interesting forms, including the world’s reduced on islands. There is also the elu- genetic theory, Speirops can no longer be treated as a separate largest weaver (Giant Weaver), sive São Tomé Fiscal, the only closed-forest genus. Several other small genera within the Zosteropidae have Príncipe Speirops Above Like most white-eyes, this Príncipe (Giant Sunbird) and seedeater (São Tomé shrike in the world, and two species so pe- also been found to be recently evolved offshoots from Zosterops Speirops is quite curious and confiding. Grosbeak), together with the smallest ibis culiar that their affinities were unknown white-eyes. In addition, Melo’s study revealed that the two sub­ Despite its large size and aberrant plumage, (Dwarf Olive Ibis). This follows a com- until recently. Dohrn’s Thrush-Babbler, species of Príncipe White-eye found on Príncipe and São Tomé recent molecular data show that speirops mon island pattern whereby small species which welcomes you to Príncipe with its are not sister taxa and so should be treated as separate species. do not form a natural group, having increase in size relative to their mainland loud, melodic song, is now known to be a It also confirms that the Forest White-eye is distinct from the Abyssinian White-eye evolved separately on São Tomé/Príncipe counterparts, and large species become sylvid warbler, closely related to the African­ African Yellow White-eye, and that the Taita White-eye is not and other white-eyes and Bioko/Mount Cameroon (see box smaller. This is probably because small Hill-Babbler. The rather drab São Tomé related to the Abyssinian White-eye complex. opposite). species can expand their niches by becom- Short-tail, which is confined to the prim­ Illustrations reproduced from BIrds of Sub-Saharan Africa (Struik Nature), courtesy of Dawie Chamberlain ing larger in the absence of competitors ary forests of São Tomé, is so odd that it

36 São Tomé and Príncipe AFRICA – BIRDS & BIRDING april/may 2012 São Tomé and Príncipe 37 event. The islands’ volcanic origin and high rainfall also played a role, creating a spectacular landscape of towering moun- tains, deep valleys and volcanic plugs. This topographic diversity created local microclimates, increasing the possibilities for successful colonisation by many dif- ferent plant and species. That said, one of the more striking aspects of birding on the islands is what is missing; there are no hornbills, woodpeckers, barbets, robins or bulbuls. Why have the endemic birds survived? Almost all bird extinctions during the past 500 years have occurred at oceanic islands, yet as far as we know, no species

martin dallimer has disappeared from São Tomé and Príncipe. Compare this with St Helena, a considerably smaller island in the tropical Atlantic that was discovered 30 years later; it has lost at least eight species and only Know before you go one endemic survives. São Tomé and Príncipe were settled in iven their amazing birdlife, stunning January are the drier periods, although Príncipe White-eye. It is also where there the 1490s by a mix of Jewish exiles, slaves Gscenery, rich history, friendly inhabit- February can be good for visiting São have been several reports of an undescribed and prisoners. Agriculture grew rapidly ants and diverse cuisine, it is surprising that Tomé’s southern forests. small owl. Access is simplest by boat, which and by 1529 São Tomé was the world’s São Tomé and Príncipe have largely been Many of the endemic birds are easily also allows you to see the subspecies of primary producer of sugarcane, largely at ignored by independent birders. Permission seen in farm bush, but visiting primary for- Príncipe Seedeater confined to Boné de the expense of the lowland forests. Only to visit the islands was hard to obtain after est is essential for locating some species. Jóquei (Jockey’s Cap), two kilometres off the southern forests were spared because independence from Portugal in the 1970s, On São Tomé, the forest surrounding the south-east coast. of their inaccessibility and extremely high but these days they are readily accessible. Lagoa Amélia, above Bom Sucesso Botanic The Tinhosas Islets, 20 kilometres south rainfall (more than seven metres per year). São Tomé can be reached by air from Libre- Garden, is a good place to find the more of Príncipe, support up to a million seabirds, We don’t know what impact the loss of ville (45 minutes), Luanda (two hours) or common endemics, including the now including Brown Boobies, Sooty Terns, and the lowland forest had on the birds, be- Lisbon (six hours). Príncipe is a 35-minute scarce Maroon Pigeon. For the more Black and Brown noddies. This makes the cause ornithological work only began in flight from São Tomé. Accommodation intrepid, a two-day hike to São Tomé peak Tinhosas the most important seabird site the late 1800s. The exploration of lava ranges from a basic ‘pensão’ at around offers unforgettable views and guarantees in the eastern trop­ical Atlantic. Do not tubes for sub-fossil remains may yet reveal US$20 per night to upmarket hotels and the pigeon and, with luck, all the en­demics land on the islets: besides being extremely that some species went extinct before be- lodges. Apart from two main local lan­ except the Dwarf Olive Ibis. The ibis is now dangerous, it causes great disturbance to martim melo (2) ing described. guages, Portuguese is widely spoken, confined to the south-east of the island, the birds. To hire a boat, contact the Bom Top The Príncipe Thrush is inexplicably was suggested to be a relic from the lineage With the decline in sugarcane produc- French is the second most spoken lan­- where it is most accessible around Ribeira Bom Island Resort or ask for the owners of rare compared to its close relative on São that gave rise to the furnariids of Central tion in the 17th century, the islands’ eco­ guage, and you will hear English used Peixe, on the old Monte Carmo estate. cariocos or botes. Tomé. It differs from the São Tomé Thrush and South America. In fact, genetic data nomy relied on supplying slave ships en by hotel staff and some guides. The São Tomé Grosbeak also occurs in this The Monte Pico Association will help by having a darker breast, bright yellow bill, show it to be a ‘tail-less’ wagtail, which you route from West Africa to America. The in- You will need a tourist visa to enter the area, but is easier to find in the south-west, with guides and other arrangements. and paler eyes and legs. can well believe when you see it nervously troduction of coffee and cocoa in the 19th country (bear in mind that obtaining a where the São Tomé Fiscal is also more Monte Pico is not active on Príncipe, but high-stepping across the forest floor. century led to further destruction of the tourist visa is tricky if there isn’t a consulate common. This requires a one- to two- can provide the necessary contacts. Bikegila Above The enigmatic São Tomé Grosbeak forest up to an altitude of 1 200 metres. or embassy in your country). Malaria is the hour boat trip from Santa Catarina to São is the guide who knows where the more was known from only three skins collected ow did such high levels of From 1908 to 1919 São Tomé and Príncipe main health concern, but the situation has Miguel, followed by a couple of hours’ hike tricky birds occur. Locally based companies in the 19th century until it was rediscovered endemism arise? The islands’ was the world’s largest cocoa producer, but improved dramatically in the past five years. into the interior. It is best to spend a couple (Navetur-Equatour and Mistral Voyages) in south-west São Tomé in 1991. It is now geographic situation played a then manufacture began to fall, particu- The only dangerous snake is the black of nights in the forest to ensure that you specialise in nature tourism. If you want known to be a giant relative of the abundant key role. The Congo rainforest, larly after World War II. Following inde- cobra, believed to have been introduced to get to grips with all the endemics. to avoid the hassle of arranging your Príncipe Seedeater. oneH of the richest centres of biodiversity in pendence in 1975, many plantations were control rats in plantations on São Tomé. As On Príncipe, most endemics are easily own logistics, several bird tour companies the world, provided a large pool of poten- abandoned, leading to the expansion of in any tropical area, care should be taken found along the path from the main town visit the islands, often coupled with trips Opposite Birds are not the only attraction tial colonisers. Furthermore, the islands are secondary forest. As a result, forest cover is with water consumption. to Bela Vista or the path from the airport to to Gabon (for example, Birding Africa, to the islands. Reaching the best birding not too far offshore to make colonisation at its highest for the past 150 years and this All the endemic birds can be seen at Ribeira Izé. Visiting the southern forests of BirdQuest and Tropical Birding). By working areas can be an adventure in itself. Here unlikely, but they are sufficiently distant to may explain why some exceptionally rare any time of year, but it is best to avoid the Príncipe is essential for the Príncipe Thrush, with Monte Pico guides, they support local two guides cross the mouth of the São make the evolution of colonisers in isola- species appear to be making something of rainy season. June–August and December– and the best bet for finding the scarce conservation efforts. Tomé River on Príncipe. tion from their source populations a rare a recovery. For example, the São Tomé

38 São Tomé and Príncipe AFRICA – BIRDS & BIRDING april/may 2012 São Tomé and Príncipe 39 RESOURCES BOOKS Guide des Oiseaux de São Tomé et Príncipe. Christy, P., Clarke, W.V. (1998) ECOFAC, São Tomé (www.ecofac.org). All birds illustrated, good texts (in French), birding itineraries. Available through NHBS (www.nhbs.com), but considerably cheaper on São Tomé (check availability with the Monte Pico Association).

The Birds of São Tomé & Príncipe: A Photoguide. Leventis, A.P., Olmos, F. (2009). A nicely presented Portuguese– English guide with photos of all endemics and most other birds. Available from STP Biologists’ Association or NHBS; proceeds support conservation projects.

Field Guide to the Birds of Western Africa. Borrow, N., Demey, R. (2004)

christian boix Christopher Helm, London. The Gulf of Guinea islands’ endemics are conveni- repetitive call, is the country’s un­official the government initiatives, two NGOs are ently grouped; laminated colour copies 5 a.m. alarm clock. But 11 species are fÁbio olmos playing key roles. The Monte Pico Associ­ of these plates are handy in the field. Threatened and an additional three are ation brings together the people with the Above This photograph of a male Giant categorised as Near-Threatened – and the best knowledge of the forests. They supply The Birds of São Tomé and Príncipe, Weaver doesn’t do justice to the bird’s most recent split of the white-eyes is likely to the guides who can take you to the most with Annobón: Islands of the Gulf of striking attribute – its giant size. From a further increase this tally. Four species are difficult endemics and are often the people Guinea. Jones, P.J., Tye, A. (2006) British distance, females can be confused with a Critically Endangered: Dwarf Olive Ibis, carrying out environmental awareness and Ornithologists’ Union, Oxford. A detailed São Tomé Oriole. Príncipe Thrush, São Tomé Fiscal and São reforestation campaigns, maintaining for- introduction to the islands and their Tomé Grosbeak. Of these, the ibis is per- est trails or working in the botanic garden birds, with a fully referenced checklist. Right In a country with four Critically haps most at risk because of ongoing il- and herbarium. The STP Biol­ogists’ Associ­ Endangered birds, the Dwarf Olive Ibis is legal hunting, a threat that also faces the ation is the local affiliate of BirdLife Interna- ONLINE RESOURCES probably the most threatened. Barely 200 increasingly rare Maroon Pigeon. tional and is the Species Guardian of three Gulf of Guinea Islands’ Biodiversity survive in the south–central region of São The future of the endemic birds of São Critically Endangered species. Its members Network (www.ggcg.st). Although not Tomé, where they are at constant risk from Tomé and Príncipe, and the islands’ other conduct censuses of the Dwarf Olive Ibis regularly updated, this remains a good illegal hunting. biodiversity, depends on the effect­ive population, ‘converting’ hunters into field website for those interested in the biota conservation of the primary forests. In assistants in the process. of the Gulf of Guinea islands. Opposite The islands are not just about early 2006 almost a third of each island The two organisations often collaborate forest birds; the rich seas support large was declared a natural park (Parque Nat­ and recently published the first ornitho- Island Biodiversity Race (www.cal numbers of tropical seabirds. Breeding ural do Obô), which includes most of the logical paper written by Santomeans. The academy.org/medialibrary/blogs/gulf species include Brown Boobies (shown remaining primary forest and a buffer zone growing awareness among the inhabitants of guinea/). Blog about the California here), White-­tailed Tropicbirds, Common of secondary forest. Nevertheless, because of the islands’ extremely rich environ- Academy of Sciences’ research into and Black noddies, and Sooty and Bridled of the small size of the islands, conser- ment, together with readily available in- bio­diversity on the Gulf of Guinea terns. There is probably also a little-known vation efforts cannot be limited to these ternational help, gives some hope that São islands. population of Band­-rumped Storm­-Petrels; protected areas. With a human popu­lation Tomé and Príncipe may yet be spared the birds are occasionally attracted to lights at growth rate of three per cent per year, de- massive extinctions and ecological havoc Monte Pico Association (montepico. night in the forested interior of São Tomé, mand for environmental resources – and typical of most oceanic islands. The victory blogspot.com). President: Luis Mário tasso leventis suggesting that they breed on the main ultimately for access to the protected areas is not certain, but the signs are definitely Almeida ([email protected]). island. Given recent splits of Band-rumped Grosbeak, which went missing for 101 are planted beneath a canopy of taller trees – will increase. Agricultural land already encouraging. Storm-Petrels at other Atlantic Ocean years after three were collected in 1888–90, that make a ‘shade forest’, a structure that covers about half the islands, and finding STP Biologists’ Association: Hugulay breeding sites, this might even represent is now known from several sites in central mimics the original rainforest and supports a model of sustainable agriculture is one ACKNOWLEDGEMENTS Maia ([email protected]). another endemic species for the islands. and southern São Tomé. most of the endemic birds. Some of these of the country’s highest priorities. With thanks to Peter Jones and Nigel Collar. Cocoa is currently the most important species are common even in the capital The conservation challenges are great, Martim Melo’s research work on the islands is Travel info: www.saotome.st/travel.php cash crop, which is good for birds. The city, notably the São Tomé Prinia which, but more and more people in São Tomé supported by the National Geographic/Waitt and www.navetur-equatour.st trees require shade to grow properly and with its noisy wing-snapping display and and Príncipe are facing up to them. Besides Grants programme.

40 São Tomé and Príncipe AFRICA – BIRDS & BIRDING april/may 2012 São Tomé and Príncipe 41