Africa’s Biomes – the Guinea-Congo Forests

Africa, in common with the rest of our planet, has been divided up into various biomes or ecosystems, each supporting unique avifauna and communities of other living organisms. These biomes or ecosystems are mostly a result of three factors – latitude, humidity and elevation. I plan to eventually feature all the various African biomes in these Africa Beat blogposts but have started with my favorite, the Guinea-Congo Forests.

A typical forest scene from the Congo forest bloc, image taken in Gabon’s Loango National Park by Adam Riley.

Tropical rainforests are most well developed in equatorial areas of low latitude, high humidity and low elevation. Africa supports approximately 30% of the world’s forests and the great bulk of these forests lie in two vast  blocs; the Upper Guinea forests of West Africa and the Congo or Lower Guinea forests of Central Africa. The Congo Forest is actually the 2nd largest forest in the world after the Amazon and is followed by New Guinea’s forests.

Map of Africa’s biomes

The Upper Guinea forests stretch from Guinea eastwards to Ghana. The Congo forests stretch from Nigeria southwards to Angola and eastwards to Uganda, with the vast bulk of this forest in the Democratic Republic of Congo. Between the two forest patches is a narrow area known as the Dahomey Gap, an area of woodlands classified as Sudan-Guinea savanna and named after Benin’s old colonial designation (Benin is situated within this woodland gap.) There are also transitional zones and outlying African rainforests beyond these two forest blocs. The Upper Guinea bloc is under severe pressure and over 80% of the original forest cover has been destroyed. The Congo bloc covers 700,000 square miles and, although it is rapidly being destroyed, a greater percentage remains; nonetheless, the UN estimates that 66% (two thirds) of the forests will be gone by 2040 unless the destruction is stopped.

A scene from the Upper Guinea forest bloc, the Kakum canopy walkway in Ghana, by Adam Riley.

The mammals of Africa’s great rainforests are quite famous – examples include Lowland Gorillas (now recognized as two species, Western and Eastern and restricted to the Congo bloc), Chimpanzees (both blocs) and Bonobos (Congo), Okapi (Congo), Forest Elephant (both), Pygmy Hippopotamus (Upper Guinea), dozens of monkey and duiker species, pangolins and much besides. The avifauna is less well known and I will cover here some of the more typical groups of birds that frequent Africa’s great rainforests.

The Tree Pangolin is endemic to Africa’s two rainforest blocs. Photographed in Ghana by Adam Riley.

Waterbirds – several species of aquatic bird are can be found on the waterways and lakes of Africa’s rainforests, the shy and elusive White-crested Tiger Heron being one of the more sought-after of these species. Hartlaub’s Duck is the only waterfowl restricted to this biome and can often be found foraging in baïs – marshy openings in the rainforest. Spot-breasted Ibis also forage in baïs or along rivers. All three species of fishing owls also occur in the rainforests, the little known and very rare Rufous in Upper Guinea, Vermiculated in the Congo bloc and Pel’s, which occurs in both forest blocs and also in woodland zones beyond the forests.

The rare and elusive White-crested Tiger Heron. Image taken in Gabon by Adam Riley.

A rare photo of a pair of highly sought-after birds – Vermiculated Fishing Owls, by Markus Lilje/Rockjumper Birding Tours. Image taken in Cameroon’s Korup National Park.

Raptors – several raptors are confined to the Guinea-Congo forests, all being rather tough to observe and occurring at low density. One of the more widespread species is the Congo Serpent Eagle – it occurs in both forest blocs where it is represented by different subspecies. Its far carrying calls are heard more often than the bird is seen. Other forest raptors include the massive monkey-hunting Crowned Eagle (which is not, however, restricted to these forests but occurs elsewhere), Cassin’s Hawk-Eagle, Red-thighed and Chestnut-flanked Sparrowhawk, Long-tailed Hawk and Red-chested Goshawk.

The Congo forest subspecies of Congo Serpent Eagle, photographed by Adam Riley in Gabon.

A pair of Crowned Eagles, Africa’s most powerful raptor, perched on an exposed forest tree. Image by Adam Riley from South Africa.

Guineafowl, francolins & Congo Peafowl – four species of guineafowl (Black, White-breasted, Crested and Plumed), two species of diminutive francolins (Forest and Nahan’s) and the mythical Congo Peafowl are all very difficult species occurring in these great forests. Hunting pressure as well as natural shyness and low densities account for few sightings, especially of the peafowl which was known from only a feather for many years. This bird became the obsession of American ornithologist James Chapin, who obtained a feather from a pygmy’s headdress during his 6-year Congo expedition and went to great extremes to prove that a peafowl actually existed in Africa, until he eventually found two old, mislabeled specimens in a Belgian museum.

A Crested Guineafowl by Markus Lilje/Rockjumper Birding Tours.

A Crested Guineafowl chick lies concealed on the forest floor. Image taken by Adam Riley in Uganda.

Parrots – Africa is not well endowed with colorful parrots, with the very familiar African Gray Parrot being the commonest rainforest species. Fortunately large flocks still occur, despite immense pressure from the captive bird trade. It is wonderful to hear and see these whistling flocks hurtling over the canopy! Other African rainforest parrots are Red-fronted Parrot and the diminutive Black-collared Lovebird.

A pair of wild African Gray Parrots feeding on palm fruit. Image taken in Gabon by Adam Riley.

Turacos – are a family of birds endemic to Africa and many of them fill the role occupied by parrots on other continents. The fabulous Great Blue Turaco makes one of the dominant sounds of the rainforests, with other species including Guinea, Black-billed and Yellow-billed.

A massive Great Blue Turaco takes flight. Image taken in Rwanda by Adam Riley.

A Guinea Turaco photographed in Ghana by Adam Riley.

Kingfishers – both forest and aquatic kingfishers can be found inside Africa’s great forests. The Chocolate-backed is a lovely rainforest canopy species and, along with African Dwarf, is not associated with water. Shining-blue and White-bellied, however, are only found around forest streams and ponds. Blue-breasted can occur both near water as well as deep in the forest.

A young Chocolate-backed Kingfisher photographed by Adam Riley in Ghana.

A digiscoped image of African Dwarf Kingfisher in Uganda by Adam Riley.

Blue-breasted Kingfisher by Markus Lilje/Rockjumper Birding Tours.

Bee-eaters – several beautiful bee-eaters are restricted to Africa’s forests and these are treated in more detail in an earlier Africa Beat blog post of mine.

Blue-whiskered Bee-eater has recently been split from Blue-headed. Image taken in Ghana by Adam Riley.

Hornbills – are also prevalent in the forests with both giant and dwarf species. The massive Black-casqued Wattled and Yellow-casqued Wattled sound like steam trains as their heavy wings pound overhead, but the diminutive Black and Red-billed Dwarf are usually located calling from the high canopy. The strange White-crested has one of the most maniacal and unusual calls of any bird and spends most of its time following monkey troops and swooping in on any insects they disturb in the forests. The larger White-thighed, Brown-cheeked and Piping feed mostly on rainforest fruits.

A massive Yellow-casqued Wattled Hornbill soars overhead. Image taken by Markus Lilje/Rockjumper Birding Tours in Cameroon.

The tiny Red-billed Dwarf Hornbill photographed in Ghana by Adam Riley.

Barbets – numerous rainforest barbets occur in Africa and these are also covered in an earlier blogpost.

The Yellow-spotted Barbet is a forest frugivore. Image by Adam Riley.

Woodpeckers – again several species are completed restricted to these forests, from Africa’s only piculet (aptly named African Piculet!) to Gabon, Melancholy, Buff-spotted, Brown-eared, Yellow-crested, Fire-bellied and Tullberg’s Woodpeckers.

Gabon Woodpecker photographed in Gabon by Adam Riley.

Brown-eared Woodpecker photographed in Uganda by Adam Riley.

Cuckooshrikes – the rainforest cuckooshrikes can count amongst their numbers some of Africa’s least know and rarest birds, including both Western and Eastern Wattled Cuckooshrikes and Grauer’s Cuckooshrike. Somewhat easier species include the stunning Blue and Purple-throated Cuckooshrikes.

The Blue Cuckooshrike is a lovely canopy species. Photo taken by Adam Riley in Ghana.

Picathartes – this is a family of birds endemic to these forests, with an Upper Guinea and a Congo bloc species. They have also been covered in detail in an earlier blogpost.

The White-necked Picathartes or Yellow-headed Rockfowl is one of two species belonging to a Guinea-Congo forest bird family. Image taken by Adam Riley in Ghana.

Illadopses – this rather dull-colored group of eight species are placed in the babbler family. They are generally very secretive and shy dwellers of the forest understorey, but their loud whistles are one of the most characteristic African rainforest calls.

Illadopses are not boldly marked and are best identified by their whistling songs. Pale-breasted Illadopsis by Cuan Rush/Rockjumper Birding Tours.

Greenbuls – are for many birders the identification nightmare of the rainforests. These bulbul relatives occur in a myriad of shapes, colors and sizes, though there are also many look-alike species. No less than 43 species occur in the two rainforest blocs, so that gives you an idea of the identification challenges posed by these birds! They occur from canopy to leaf-litter level and often form the core of multi-species forest bird flocks.

The Little Gray Greenbul is one of many rather plain look-alike species. Image taken by Adam Riley in Ghana.

The Red-tailed Greenbul is more distinctive and often puffs out its white throat. Image taken by Adam Riley in Uganda.

Bristlebills are a colorful but secretive group of rainforest greenbuls. This is a Red-tailed Bristlebill photographed by Markus Lilje/Rockjumper Birding Tours.

Alethes – unlike greenbuls, these are distinctive and shy denizens of the rainforest understorey. Most of the thrush-like alethe species are ant followers and can be found attending to marauding safari ant trails (Africa’s equivalent of army ants).

The Brown-chested Alethe is a shy bird usually only detected around safari ant swarms. Image taken by Adam Riley in Uganda.

Apalises – generally provide African birders with warbler-neck syndrome – these small (but long-tailed) warblers are usually canopy species and it typically takes a telescope or canopy walkway to appreciate their beautiful colors and patterns. Ten species occur in the region under discussion.

The lovely Black-capped Apalis is a high canopy specialist. Image by Markus Lilje/Rockjumper Birding Tours.

Flycatchers – are a mixed bunch of small to medium sized passerines displaying a remarkable variety of shapes, plumages and colors. The lovely paradise-flycatchers generally display long tails and are showy, whilst others such as Yellow-footed are tiny, shy species. White-browed Forest Flycatcher is found around forest steams but several are canopy specialists, such as busy flocks of Chestnut-capped. Several are very tough – few birders, for example, can claim Nimba, Tessmann’s and Olivaceous Flycatchers to their lifelists.

A Red-bellied Paradise Flycatcher from Gabon by Adam Riley.

The Gray-throated Tit-flycatcher is a rather secretive forest canopy species. Photographed by Adam Riley in Gabon.

The Olivaceous Flycatcher makes up for its looks by its rarity. Photograph taken in Ghana by Adam Riley.

Wattle-eyes – belong to a family of birds endemic to Africa and many of their members are rainforest specialists. They are generally small birds displaying major sexual dimorphism (ie different male and female plumages). Both understorey and canopy species exist and some, such as Yellow-bellied Wattle-eye, are very colorful, but many are just black and white.

The beautiful Yellow-bellied Wattle-eye photographed in Cameroon by Markus Lilje/Rockjumper Birding Tours.

A male Chestnut Wattle-eye is black and white; only the female shows chestnut plumage. Image by Markus Lilje/Rockjumper Birding Tours.

Starlings – also come in a variety of shapes and sizes. Although the bulk of Africa’s starlings are savanna species, several have evolved to become rainforest specialists. Rainforest glossy starlings include the Upper Guinea endemic, Copper-tailed, and the more widespread Purple-throated. Several species of the red winged starling group are also rainforest denizens including Chestnut-winged and Narrow-tailed.

The Upper Guinea endemic Copper-tailed Starling is a threatened species, as are most of the other Upper Guinea endemics. Image taken in Ghana by Adam Riley.

Sunbirds – are another abundant group of rainforest species, several of which provide identification challenges. Guinea-Congo forest species include the lovely Buff-throated, Green-throated, Blue-throated Brown, Little Green, Bates’, Fraser’s, Gray-headed, stunning Johanna’s and Tiny Sunbirds.

The uniquely patterned Buff-throated Sunbird. Image taken in Ghana by Adam Riley.

Weavers – are further discussed in this blog post. Several rainforest species exist and include the canopy foraging Preuss’ Golden-backed, Maxwell’s Black and the 10 malimbe species.

Preuss’ Golden-backed Weaver is a rainforest canopy species with a typical foraging behavior of peering under small branches for hidden insects. Image taken in Ghana by Adam Riley.

Finches – Africa is home to numerous stunning finch species, of which several are forest dwellers. The 4 species of negrita or negrofinch are usually found at higher levels in the forest, antpeckers at midlevel (Woodhouse’s Antpecker used to languish under the name of Woodhouse’s Red-headed Flowerpecker-weaver-finch!) whereas twinspots, bluebills and seedcrackers are usually found at lower levels.

A rare photo of a male Red-fronted Antpecker, a little known species. Image taken in Ghana by Adam Riley.

A female Western Bluebill by Jonathan Rossouw.

Well over 1,000 species of birds occur in the Guinea-Congo forests, so this is by no means a thorough coverage but just a brief overview of some of the groups and species that exist in these biodiverse rainforests.