Last month I was lucky to be able to sneak out to Casamance for a few days, a region I hadn’t visited since May 2017 when I paid a brief visit to Kolda. Together with Bruno Bargain, resident birder in Ziguinchor, we explored several areas and managed to see a good number of interesting birds. But before going through the highlights of our trip, it’s about time we gave a few more details about the discovery of a new species for Senegal: Turati’s Boubou, found last October by Bruno near Ziguinchor. This West African endemic appears to be resident in small numbers in at least one locality, but it’s likely that it is actually well established in a few other forests of Basse-Casamance.
This latest addition to the national list was expected, so not a big surprise – but still significant, given that this species was so far only known to occur in Guinea-Bissau, Guinea and Sierra Leone. Our assumption that it should be present in Casamance was based on the fact that the species is present just across the border in northern Guinea-Bissau, and that suitable habitat exists in Basse-Casamance which up to recently was one of the least well known regions, ornithologically speaking, of Senegal. A member of the Malaconotidae, Turati’s Boubou is not uncommon within its restricted range, but its secretive habits make it difficult to find – something I experienced first-hand last month when trying to catch a glimpse of one of the Ziguinchor birds: impossible! Outside of the breeding season (likely just before and during the rains, i.e. May/June – October) they don’t appear to be very vocal and don’t necessarily respond to playback. We heard at least two birds singing briefly – a typical ghost-like boubou song – and while at one point one bird was calling just a few meters away in dense undergrowth at the edge of a remnant forest patch, it just did not want to show itself. Next time! The only recording I managed to obtain was of this call, which when we first heard it was a perfect match of the call recorded by Ron Demey in western Guinea, assumed to be that of a female (included in Claude Chappuis’s CD set). Bruno so far obtained just a single picture but was lucky to get good views of several birds, including an supposed pair (at least three different birds have been found since the first sighting on October 10th. Update 13.02: here’s a picture taken just this morning by Bruno, after an hour of patiently waiting for the bird to show…
More field work is of course needed to get a better sense of this little known species’ breeding cycle, distribution and population size in Casamance; I certainly hope to be able to contribute to this effort in coming months. So for now, here’s just a picture of the habitat in which these birds were found: note the dense undergrowth in otherwise fairly open, dry forest.
Of note is that there is at least one unsubstantiated record of Tropical Boubou in Casamance and as a result the species is often listed – incorrectly in my view – as occurring in Senegal: this sighting may in fact relate to Turati’s Boubou which Tropical resembles fairly closely. Even its vocalisations are extremely similar – Chappuis wrote that “it is barely possible to distinguish the two species acoustically” – so it wouldn’t be surprising were this actually Turati’s.
Another target of my short trip was Western Square-tailed Drongo, aiming to obtain sound recordings of this newly described cryptic species which is now included in the reference list maintained by the International Ornithological Committee (IOC 9.1) as a valid species, Dicrurus occidentalis. More on this discovery in this recent blog post. The latest IOC list, published just last week, also includes another taxonomic change in the Dicruridae that affects the Senegal list: the two subspecies of Fork-tailed Drongo D. adsimilis ranging from west to north-central Africa are now elevated to Glossy-backed Drongo D. divaricatus (Fork-tailed Drongo sensu strictu is found in central, eastern and southern Africa). More on the recent taxonomic revisions in a later post…
Anyway, back to Casamance: thanks to Bruno’s excellent field knowledge, we easily found Western Square-tailed Drongo in two locations, and several decent recordings were obtained. While more material is needed, we hope that these will eventually contribute to further our knowledge of vocal differences between occidentalis and its “sister species” Sharpe’s Drongo D. sharpei. As usual, my recordings can be found here on xeno-canto.
During our 72 hours in the field (16-19.01), we specifically targeted a few sites in atlas squares with no or very few records so far, particularly in the area between Bignona and Tionck-Essil where we spent one night in a campement villageois (more on the Casamance bird atlas further down and in this article). All in all we collected close to 400 records of some 175 species, which just highlights the richness of Basse-Casamance.
Birding from dawn to dusk – brilliant!
In addition to the boubou and drongo, some of the highlights were Spotted Honeyguide (lifer! recording of its distinctive song here), Ovambo Sparrowhawk (poorly known and rarely reported species in Senegal), Woolly-necked Stork (a bird flying in from mangroves near Elana), great views and good recordings of Ahanta Francolin which seems to be far more widespread and less of a forest specialist than field guides suggest. And of course, a range of other typical forest species that in Senegal are largely restricted to this part of the country: Buff-spotted Woodpecker, Piping Hornbill, Grey-hooded Capuchin Babbler, Green Crombec, Green Hylia, Little Greenbul, Guinea Turaco, Grey-headed Bristlebill, Puvel’s Illadopsis, Olive Sunbird, etc. (Indicateur tacheté, Epervier de l’Ovampo, Cigogne épiscopale, Francolin de l’Ahanta, Pic tacheté, Calao siffleur, Phyllanthe capucin, Crombec vert, Hylia verte, Bulbul verdâtre, Touraco vert, Bulbul fourmilier, Akalat de Puvel, Souimanga olivâtre).
Obtaining good views – or any views at all for that matter – of these forest specials was often difficult, so I don’t really have any good pictures to share. The two below illustrate quite well how challenging this can be in the forest, especially with my bottom-of-the-range camera:
A few scarce Palearctic migrants were seen, including Booted Eagle, European Bee-eater, House Martin, Grasshopper Warbler – the latter in dense grasses on the edge of dry rice paddies near Ziguinchor, a rare record this far south although the species is probably regular in winter (Aigle botté, Guêpier d’Europe, Hirondelle de fenetre, Locustelle tachetée).
This African Pygmy Goose was one of at least nine birds seen on a pond close to those same extensive rice paddies, where they seem to have bred. Other birds in this area, which we visited late afternoon on my first day in town, included Giant Kingfisher, Purple Heron, Piping Hornbill, Quailfinch, Lanner, Whinchat, and so on (Martin-pêcheur géant, Héron pourpré, Calao siffleur, Astrild-caille, Faucon lanier, Tarier des prés).
Similar habitat often holds pairs of Abyssinian Gound Hornbill which appears to still pretty common in Casamance, allowing me to finally see this impressive bird – by some considered to be one of the ugliest birds roaming our planet, though I beg to differ! – which somehow had managed to elude me so far in Senegal. I’d only ever seen it in Awash NP in the Ethiopian Rift Valley, many years ago… We found a small family group feeding in fields just east of Bignona, and another two birds a few kilometers further along the road to Elana. In the end I saw or heard several birds I hadn’t seen before in Senegal, including 4 lifers, bringing my country list to 507 species by the end of the trip. With the addition of Turati’s Boubou, the national list now stands at 677.
I’d like to highlight once again the fabulous work that Bruno and colleagues from the APALIS association are doing in Casamance: with very limited means – but with a great deal of passion and perseverance – they are slowly but surely putting together a comprehensive picture of the distribution and abundance of birds across the region, currently covering some 450 species. Not an easy feat considering how remote and inaccessible many parts of this remarkable region of Senegal are; Casamance is arguably the most diverse and in many ways the most pleasant and most exciting part of the country, and I for one certainly wish I were able to spend more time there. The latest APALIS newsletter (in French, available here as a PDF) contains multiple interesting records and new discoveries, such as the first records in nearly 40 years in the region of White-crested Tiger Heron (with a brilliant picture!), Senegal Lapwings (six near Kamobeul on 30.9.18; despite its name this is a real rarity in Senegal!), and Winding Cisticola; the first regional records of Glossy Ibis, Sun Lark, Singing Bush Lark, Brown-throated Martin, Great Reed Warbler, confirmed breeding of White-backed Night-Heron, and much more (Onoré à huppe blanche, Vanneau terne, Cisticole du Nil, Ibis falcinelle, Cochevis modeste, Alouette chanteuse, Hirondelle paludicole, Rousserolle turdoïde, Bihoreau à dos blanc). The most significant records will be included in the next “Recent Reports” of the African Bird Club bulletin, to be published in March.
In addition to the routine atlassing field work, our friends are now embarking on a project to survey some of the main heronries and other water bird colonies, using a drone to take aerial pictures of the colonies located in dense inaccessible mangroves, thus enabling estimates of the number of nests for each species. The association is currently raising funds to finance the purchase and operating costs of the drone, so please chime in, every bit helps! Link to fundraising campaign here. And please consider supporting APALIS by becoming a member, which at just 15 Euros is just a, well, bargain 😉
And of course, if you have the opportunity to visit Casamance, please get in touch so we can make sure that your observations get incorporated into the database; Bruno can offer advice about where to go or which birds to target more specifically. Nearly three times the size of Gambia, with a good range of different habitats represented, there’s something for everyone. Any birder coming to Senegal should definitely consider visiting this region, and more generally try to get off the beaten birding track – forget about Djoudj, Richard Toll, the Saloum or even Wassadou (and yes even Technopole): Casamance is the place to be!
Enfin, un grand merci à Bruno et sa petite famille pour l’accueil à Kantène!
It’s not every day that a new bird species is described from West Africa, but thanks to some remarkable detective work by Jérôme Fuchs and colleagues, we now know that the “Square-tailed Drongos” occurring in West African forests should be considered a separate species. The researcher from the French National Museum of Natural History and his co-authors from Guinea, Denmark and the US describe what they named Western Square-Tailed Drongo Dicrurus occidentalis in a paper published earlier this year in the journal Zootaxa: Taxonomic revision of the Square-tailed Drongo species complex (Passeriformes: Dicruridae) with description of a new species from western Africa. The full paper is available on ResearchGate and a nice summary is to be found on this site. The abstract is reproduced below.
In summary, Western Square-tailed Drongo is genetically distinct from its “sister species” Sharpe’s Drongo D. sharpei which occurs further east, but cannot be safely identified in the field. The only morphological differences as per current knowledge are bill shape and size: culmen length, bill width and bill height were found to be sufficiently different from Sharpe’s. The authors provide a detailed description of the holotype, a bird collected by Raymond Pujol and Jean Roché on 18 December 1959 in Sérédou in the N’zérékoré region of Guinea. According to the authors, Western Square-tailed Drongo and Sharpe’s Drongo diverged about 1.3 million years ago, resulting in substantial genetic divergence (6.7%).
Here’s one of the only pictures I could find online of what should now be considered D. occidentalis, from La Guingette forest near Bobo-Dioulasso in Burkina. There’s also this one in the Macaulay Library of a bird in the hand from central Nigeria in 1981.
And for comparison purposes, here’s one of D. ludwigii from South Africa:
Western Square-tailed Drongo is known to occur in secondary forest and gallery forest from coastal Guinea to Nigeria, likely as far east as the Niger/Benue River system in Nigeria. It also occurs in Senegal and in nearby Gambia, more precisely in the forests of Basse-Casamance but also in the Dindefelo area where it was recently found. Of note is that the only publicly available sound recording of this taxon is from Dindefelo¹, made by Jean-François Blanc and friends in March 2016 when they found several Square-tailed Drongos on the edge of the Dande plateau (see Blanc et al. 2018. Noteworthy records from Senegal, including the first Freckled Nightjar, ABC Bull. 25 (1), for more details and a photograph of one of the drongos). There are several relevant recordings on Claude Chappuis’s CD set, one from SW Senegal and a few different call types from gallery forests in S Ivory Coast.
More sound recordings are needed to establish the extent of vocal differences between the various taxa within the Square-tailed Drongo “species complex”; it is mentioned in the species account on HBW that there are clear regional differences in vocalisations: in W Africa more muted calls compared with E birds, which have more “ringing” tone – not surprising now that it is clear that these are different species! As is often the case with closely related and morphologically very similar species, the song and calls are often sufficiently different to be useful to safely identify the species. I have some from Mozambique, but now just need to go to Casamance – another good excuse to make it out there¹.
Of course, I was now wondering whether any of the drongos that we saw in February in the Dindefelo forest and along the nearby Gambia river, were Square-tailed rather than Fork-tailed Drongo which is the default species throughout… but at least on the picture below Fork-tailed can be confirmed.
The “new” species also occurs further east, creeping into SW Mali and S Burkina Faso where some decent gallery forest still remains. In this respect, the distribution map in the paper isn’t very accurate and slightly misleading as it doesn’t include these two countries, and the range shown for Senegal is way too large. Hopefully the precise distribution, both in Senegal and elsewhere in West Africa, will be further refined in coming years.
We describe a new species of drongo in the Square-tailed Drongo (Dicrurus ludwigii) complex using a combination of biometric and genetic data. The new species differs from previously described taxa in the Square-tailed Drongo complex by possessing a significantly heavier bill and via substantial genetic divergence (6.7%) from its sister-species D. sharpei. The new species is distributed across the gallery forests of coastal Guinea, extending to the Niger and Benue Rivers of Nigeria. We suspect that this taxon was overlooked by previous avian systematists because they either lacked comparative material from western Africa or because the key diagnostic morphological character (bill characteristics) was not measured. We provide an updated taxonomy of the Square-tailed Drongo species complex.
¹ Update 2.1.19: in mid-January I managed to sneak out to Casamance for a few days, where I obtained several decent recordings of these drongos, now available on xeno-canto. I also managed a couple of decent pictures, one of which can be found here.