Cuckoo Finch, New to Senegal
Following the addition of Turati’s Boubou (Ziguinchor, October 2018) and Willcocks’s Honeyguide (Dindefelo, January 2019), another scarce Afro-tropical species was recently added to the avifauna of Senegal: Cuckoo Finch, Anomalospiza imberbis (in French: Anomalospize parasite). Three birds were found on 17 February in moist grassland north of Oussouye in Basse-Casamance, by Bruno Bargain, Gabi Caucal and Adrien de Montaudouin.
While not necessarily straightforward in the field, their identification could be confirmed based on a few pictures that the team were able to obtain: small, compact drab-yellow finch with a short yet deep conical bill, short tail with pointed central rectrices, pale central crown stripe, small beady black eye, long pale claws. The two-toned bill (pale base of lower mandible contrasting with darker upper mandible) is typical of juveniles, while the yellowish underparts and throat suggest that this bird is a young male.
Several birds were seen again a couple of weeks later by Bruno, including two singing males: it’ll be interesting to see whether this little group is resident here and whether more will be found in nearby locations in coming months… there’s definitely a lot of potential, with quite a bit of suitable habitat elsewhere in the area.
As with the boubou, the discovery of this species in SW Senegal was to be expected given that it has been seen several times in recent years just across the border in Gambia, prompting me to include the Cuckoo Finch on our list of the birds of Senegal with a question mark (“presence to be confirmed”) when I initially compiled the list last year. The checklist is accessible through this new page that was recently added to the Resources section of this website. Cuckoo Finch is species number 679 on the national list! (though to be fair, this includes five for which definite proof is lacking, and which remain to be confirmed)
Cuckoo Finch is indeed a widespread yet local and uncommon species throughout Sub-Saharan Africa, and particularly in West Africa its status and patchy distribution remain poorly known. It occurs in Sierra Leone, Liberia, Cote d’Ivoire as well as in southern Mali, and probably also in Guinea and Guinea-Bissau though as far as I know there are no records in the latter country. The presence in Guinea is based on an old specimen from Mount Nimba, which I was fortunate to examine in the collection of IFAN here in Dakar, picture below. In Gambia it was first recorded in 1969, on 24 September by O. Andrew. The only further details I found on this record are in Morel & Morel (1990), who state that “about a dozen were seen well in Sept.-Oct. 1969 near Banjul”. It then took more than 40 years for the next record to be obtained, more precisely at Kartong Bird Observatory where three birds were caught and ringed on 24 Feb. 2013; in subsequent years the species was again caught or seen on a few occasions at KBO, at most 14 birds on 27 April 2014, and again several birds in May-October 2017. All were non-breeding or young birds, with no evidence of local breeding (O. Fox, J, Cross).
Given these more or less regular sightings at Kartong, which lies right on the border with Casamance, it would make sense if the species were also present around Abene, Kafountine, Diouloulou or other nearby locations. We’ll try to explore some of these sites in coming months, particularly during the breeding season, i.e. during the rains. The finders are currently writing up a note to formally publish their discovery.
Also known as Parasitic Weaver, the “unusual finch” as per its scientific name is the unique representative of its genus, having previously been linked to weavers and even canaries. It is now included in the viduids as it is most closely related to the whydahs and indigobirds (see e.g. Lahti & Payne 2003). Just like these birds, it is a brood parasite, laying its eggs in nests of cisticolids (cisticolas and prinias), apparently up to c. 30 eggs per season (!), in batches of 1-4 eggs per “set”. Zitting Cisticola and Tawny-flanked Prinia may be the most likely host species in Senegal and Gambia.
There’s of course a lot more to be said about this peculiar songbird, for instance how females adopted a mimetic strategy to fool its hosts: Feeney et al. (2015) demonstrated how “female Cuckoo Finch plumage colour and pattern more closely resembled those of Euplectes weavers (putative models) than Vidua finches (closest relatives); that their Tawny-flanked Prinia hosts were equally aggressive towards female Cuckoo Finches and Southern Red Bishops, and more aggressive to both than to their male counterparts; and that prinias were equally likely to reject an egg after seeing a female cuckoo finch or bishop, and more likely to do so than after seeing a male bishop near their nest.” Fun fact: I happened to meet Claire Spottiswoode, one the co-authors of the paper and specialist of brood parasites, on their southern Zambian study site while they were conducting field work in March 2013… but I failed to find any Cuckoo Finches!
For some more on parasitic birds, here’s a good start.
Plenty of other good birds were seen in Casamance last month, including the first White-tailed Alethe (Alèthe à huppe rousse) in many many years, Lesser Moorhen (Gallinule africaine), Ovambo Sparrowhawk (Epervier de l’Ovampo), Bluethroat (Gorgebleue à miroir), Forbes’s Plover (Pluvier de Forbes), European Golden Plover (Pluvier doré), Yellow-legged & Kelp Gulls (Goélands leucophée et dominicain), and quite a few more scarce species. With a bit of luck, Gabi and Etienne will find some time to write up the highlights of what was once again an epic trip across Senegal.
Meanwhile in Dakar, seabird spring migration is in full swing, with the first Long-tailed Skuas, Sooty Shearwaters, Roseate Terns and so on passing through in recent weeks (Labbe à longue queue, Puffin fuligineux, Sterne de Dougall). More on this in due course.
Many thanks to the finders for allowing me to write up this post, and to Olly Fox for providing info on the Kartong records.
Iberian Chiffchaff in West Africa
We’re continuing our little series on the status of some lesser known passerines that spend the winter in Senegal. This time round we’re looking at Iberian Chiffchaff (Pouillot ibérique), yet another drab songbird that can be tricky to identify unless of course it’s singing. We won’t go much into its identification in this post; a lot has been written on the topic, though unfortunately the standard West Africa field guides lack sufficient detail and may oversimplify the matter somewhat. In addition, few if any of the local guides really know how to identify the species in the field, and not all visiting birders pay much attention to these LBJs.
There are a few subtle differences in plumage, but generally it’s not easy to identify these birds on plumage and “jizz” alone.. so maybe it’s useful after all to summarise key characteristics here. Lars Svensson, in what is still one of the main reference papers on Iberian Chiffchaff identification (2001), neatly listed the following field characters in comparison with Common Chiffchaff:
- As a rule, the entire upperparts of ibericus are purer moss green than on Common Chiffchaff, lacking the brown tinge on crown and mantle usually present in collybita in freshly moulted plumage in early autumn a very slight brownish tinge can be found on the greenish upperparts of some Iberian Chiffchaffs
- More tinged yellowish-green on sides of head and neck, and has no buff or brown hues at all, or only very little of it behind the eye and on ear-coverts. The breast is whitish with clear yellow streaking
- Typically, has vivid lemon yellow undertail-coverts, contrasting with a rather whitish centre to the belly
- Supercilium on average more pronounced and more vividly yellow, particularly in front of and above the eye
- On average, the legs are a trifle paler brown on Iberian than on Common Chiffchaff, though many are alike
- Bill is very slightly stronger [though I find this one of very little use in the field!]
Clearly these are mostly subtle differences and when identifying on plumage alone, a combination of characters should typically be used. Confusion with Willow Warbler is not unlikely, even by experienced birders, and I’m assuming that at least some Iberians are noted as Willow Warbler, especially in mid-winter in northern Senegal when Willow Warbler should in fact be rare, as it winters chiefly in the forest zone further south. The longer wings, pale underparts and paler legs can indeed result in striking similarities between Willow and Iberian. A good pointer to separate these two is that the latter typically dips its tail while feeding, whereas Willow, Warbler characteristically flicks its wings while moving its tail sideways.
The two pictures below were taken by Frédéric Bacuez near Saint-Louis, on 18.4.16 (top) and 20.1.13 (bottom), and while it’s probably impossible to be certain, I do tend to believe these are Iberian Chiffchaffs.
The vocalisations on the other hand are far more reliable and are indeed always ideal in order to confirm an Iberian Chiffchaff, particulary the song. While there’s some variation and there may be some “mixed singers”, the difference with Common Chiffchaff is usually obvious (though maybe a bit less so on this one from Wassadou). It’s worthwhile pointing out though that besides the quite distinctive song, a good yet undervalued criterion is the call of the species – see this nice summary on the Turnstones blog (and also Collinson & Melling 2008, who state that the call “in sharp contrast to that of Common Chiffchaff, is downwardly inflected, from 5 to 3 kHz, transcribed as ‘piu’ or ‘peeoo’, perhaps reminiscent of the call of Siskin” – now compare with my recording from Technopole (same bird as in the song recording): I wouldn’t say this sounds like a Siskin – and even less like a Bullfinch! – and at 3.5-6 kHz the frequency is clearly a bit higher as can be seen on the sonogram below (click to enlarge).
Status & Distribution in Senegal
Up to not so long ago, most authors considered Iberian Chiffchaff to be a resident or partial migrant, mostly due to lack of reliable identification criteria at the time. Svensson (again!) provided the most comprehensive overview of our knowledge of the wintering areas in his 2001 paper, concluding that it is “a long-distance migrant which winters primarily in tropical Africa“. This assumption was however based on very few specimens and even fewer reliable field observations. One of these is of a bird “singing like an Iberian Chiffchaff” by Yves Thonnerieux from northern Ghana, and the only two specimens from wintering grounds are from Mali in 1932 (Segou) and 1955 (Bamako); both were found by Svensson in the museum of natural history in Paris (MNHN). A third specimen was collected in January 1955 in Tunisia, suggesting that some birds may winter north of the Sahara; Svensson also showed that the species is present during spring migration in Morocco (at least late March – early April).
With increased “observer awareness” and better reporting systems, recent years have seen a clear increase in field observations from West Africa, described further below. Combined with the absence of any winter records from the Iberian peninsula, I think it’s quite well established now that indeed most if not all Iberian Chiffchaffs winter south of the Sahara.
To further refine its status in West Africa, we turn to our usual suspects: Morel & Morel provide a single record, presumably obtained by themselves, of a singing bird at Richard Toll on 22-24.2.87 (this is probably the unpublished record “from tropical Africa” that Svensson refers to). This can safely be assumed to be the first published record for Senegal; identification was apparently largely based on song since they write that they compared the song with recordings by Claude Chappuis. It’s quite easy to miss out on this observation though, as ibericus (or brehmi as it used to be known) is only referred to in the annex of Les Oiseaux de Sénégambie (1990), as their sighting was obviously too recent to be included in the near-final manuscript of their book. Of course, the species was at the time still considered to be “just” a subspecies of Common Chiffchaff. Rather curiously, the Morels refer to a significant proportion of Scandinavian Common Chiffchaffs (ssp. abietinus) – up to half! – though we now know that these populations tend to winter in eastern Africa, heading in a south-easterly direction in autumn. Could it be that these were actually Iberian Chiffchaff rather than abietinus?
Moving on, Rodwell and colleagues (1996) refer to three records of calling (singing?) birds in the Djoudj NP in Jan 1990, Jan 1991 and Feb 1992. Sauvage & Rodwell (1998) do not provide any additional records: up to the mid-nineties, ibericus was obviously still considered a rare to scarce winter visitor to northern Senegal. More than a decade later, Borrow & Demey still consider the species’ distribution in Senegal as “inadequately known”, and their map only shows the lower Senegal valley.
As is the case with quite a few other little known taxa that were recently elevated to species rank – think Moltoni’s Warbler, Seebohm’s Wheatear, Atlas Flycatcher – these past few years our knowledge has greatly increased, and it is clear that Iberian Chiffchaff is indeed quite frequent in northern Senegal. Recent reports mainly come from the Djoudj NP – obviously a key wintering site, with decent densities – and from around Richard Toll and Saint-Louis (e.g. Bango, Trois-Marigots, Langue de Barbarie, and see picture above). There are however a number of recent records elsewhere that suggest that the species is more widespread: last winter I was lucky to find a singing bird at Technopole which is thought to be the first record from Dakar; there are also a few reports from the Somone lagoon, though not sure that these are reliable (I have suspected the species here before, but never been able to confirm based on call or song). Rather intriguingly, the species was also seen several times along the Gambia river at Wassadou these past two years: first in December 2017, then more than two months later at least one singing bird that we found on 24.2.18, and again this winter (7.1.19). Finally, another singing bird was reported near Kounkane, Velingara, on 28.1.18 (G. Monchaux) – to our knowledge the first record from Casamance. The observations in these southern locations suggest that the species is more widespread and that it can turn up anywhere in Senegal.
In Mauritania, it appears that up to recently the only records were obtained during extensive field work conducted by the Swiss Ornithological Station, with several birds captured both in spring and in autumn 2003 (Isenmann et al. 2010). There are several more recent reports from around Nouakchott mainly, presumably of birds passing through. In addition to the two aforementioned specimens from Mali, the only other record from that country that I’m aware of is of a singing bird that I recorded in a hotel garden in Bamako, where it was singing for at least a week in January 2016. Burkina Faso should also be part of the regular range, though there again there are just a couple of records, most recently a singing bird reported by van den Bergh from the Bängr-Weeogo park in Ouagadougou in December 2011.
The Xeno-canto range map, which is largely based on BirdLife data, is probably the most accurate when it comes to the winter range (though not for the breeding range, the species being absent from most of central and eastern Spain). It should also include all of northern Senegal, or at a minimum, the lower and middle river valley, particularly the Djoudj NP which is omitted from the map below. I’m not sure that the species has been reliably recorded from Gambia even though there are several unverified observations on eBird. Further north, there are several winter records from Western Sahara between early December and early February, mainly at coastal sites (Bergier et al. 2017), suggesting that not all Iberian Chiffchaffs cross the Sahara. Spring migration is noted from mid-February to mid- or end of April.
Iberian Chiffchaff should be present in Senegal and generally throughout its winter quarters from about October to early or mid-April; the earliest observation I could find is one of a bird reported singing east of Richard Toll on 27.10.15. A Danish group reported two birds in Djoudj in early November 2017, but other than that almost all records are from December – February during the peak orni-tourist season.
Paulo Catry and colleagues (including our friends Miguel and Antonio!) showed marked differential distance migration of sexes in chiffchaffs, with females moving further south than males. Their study did not distinguish between Common and Iberian Chiffchaff, but because south of the Sahara (Djoudj mainly), sex-ratios were more male-biased than predicted by a simple latitude model, their findings suggest that among the chiffchaffs wintering in West Africa, a large proportion is composed of Iberian birds, providing further support that these birds are long distance migrants. The ringing data from Djoudj also showed that chiffchaffs display differential timing of spring migration, with males leaving the winter quarters considerably earlier than females [typically, male migrant songbirds arrive a little earlier on the breeding grounds than females, presumably so they can hold and defend a territory by the time the females arrive].
Finishing off with some essential ibericus reading…
- Collinson & Melling, 2008. Identification of vagrant Iberian Chiffchaffs – Pointers, pitfalls and problem birds. British Birds 101.
- Svensson, L. 2001. The correct name of the Iberian Chiffchaff Phylloscopus ibericus Ticehurst 1937, its identification and new evidence of its winter grounds. Bull. B. O. C. 121.
Identification of Seebohm’s Wheatear in Senegal
Last winter, I had the chance to have a closer look at a species that is relatively little-known, particularly on its wintering grounds: Seebohm’s Wheatear, a former subspecies of Northern Wheatear that was fairly recently (though long overdue it seems) recognised as a full species by many authors, though surprisingly not yet by IOC. These neat little birds have a pretty restricted breeding range, only occurring in the Atlas mountains of Morocco and Algeria. A couple of years ago I had the chance of seeing these birds for the first time, more precisely in May on their breeding grounds at Oukaimeden, birding hotspot incontournable of the Moroccan High Atlas. As such it was particularly nice to meet up with them on their Sahelian wintering grounds a few months later, during our memorable trip up north in January 2018.
Wheatears can be tricky birds to identify, with several species often posing a bit of an ID challenge, and Seebohm’s is no exception. However, nothing much has been written about the identification of first-winters and adults in non-breeding plumage¹, and depictions in standard field guides may be misleading or even incorrect. In an effort to further our knowledge of the species, we thought it may be useful to summarise what we know based on our limited experience with Oenanthe seebohmi in the field here in Senegal, combined with a brief study of available pictures. Note though that by no means is what follows necessarily a comprehensive overview; additions and corrections are most welcome as usual.
A second blog post will focus on the status & distribution of the species.
Identification in winter
While straightforward to recognise in spring, Seebohm’s Wheatear on its Sahelian wintering grounds can be difficult to identify, mainly because they may superficially resemble Desert or Black-eared Wheatear, while young birds and some females may look like Northern Wheatear. We’ll start by reviewing field characters as found in the most relevant literature: mainly the excellent Robins and Chats (Clement & Rose 2015), Nils van Duivendijk’s Advanced Bird ID Guide (2010), and the recently published seminal reference guide by Shirihai & Svensson (Handbook of Western Palearctic Birds: Passerines, 2018). Let’s see how these can be applied to some of the pictures of presumed Seebohm’s taken in winter.
- Size & overall impression are very similar to Northern Wheatear, though it is slightly smaller than that species – something that’s not necessarily obvious in the field unless maybe in direct comparison to nominate Northern; it’s clear though that Seebohm’s definitely doesn’t look larger than Northern as is the case with ‘Greenland Wheatear’ (= ssp. leucorhoa) where the size difference is usually obvious in the field.
- Structure is typical of wheatears and does not appear to be very different from Northern either; the wing is supposedly slightly shorter, though this is not really obvious in the field, several of the pictures presented here actually show rather slender long-winged birds with an important primary projection, rarely giving a more compact appearance. On most pictures presented here we can however verify that the primary projection is slightly less than the length of exposed tertials (Shirihai & Svensson).
- The bill and tail are said to be “rather longer” than Northern, but these differences are again likely of little use in the field, and I’d imagine that there’s some overlap between species – more measurements on museum skins are likely needed to confirm this.
- In all plumages, the black terminal tail band is narrower than in Northern Wheatear (on outer tail feather, ca. one third of the length of the feather is black), though yet again this is not a very useful field character unless good pictures of the tail are obtained.
- Another key difference is that the underwing coverts are entirely black in males, while in females there are pale streaks on dark underwing coverts, unlike in Northern.
Adult and second-year males are generally straightforward to identify in autumn and winter, when they largely retain their distinctive head pattern, only to a limited degree obscured by pale fringes, combined with very pale underparts and “largely greyish or slighly sandy-grey” upperparts. As a result, adult males should be easy to pick out in autumn and winter, despite not showing the crisp black/grey/white plumage typical of spring males. Still, they remain very distinctive and are unlikely to be confused with any other species, such as this one from the end of March on wintering grounds in southern Mauritania, photographed by the late Robert Tovey (Birding for a lark blog):
The two birds below were photographed in Nouakchott by Rob Tovey, at the end of September and mid-October, respectively. Both are clearly males, and while not very grey, I believe both are 1st year birds (note moult limit on first bird). However, ageing of these birds “requires close inspection of moult and feather wear and pattern in wing” (Shirihai & Svensson) and is often not straightforward – more on this below. This bird on Afbid from January near Richard-Toll, photographed by Nik Borrow, clearly shows an adult-type male, with a largely grey crown, mantle and scapulars.
There appears to be some confusion about the plumage of adult females in the literature, with some authors only mentioning that adult females have a “(dark) grey mottled throat” (van Duivendijk), whereas Svensson in the Collins Bird Guide writes that “females and imm. are often inseparable from [Northern] Wheatear unless showing hint of mottled grey throat (rare though)”. Clement & Rose provide illustrations of an adult male and a dark-throated adult female, but don’t bother illustrating typical females, nor do they show any birds in autumn and winter. They do note that females are variable, ranging from closely resembling typical females of Northern Wheatear, to showing brown ear-coverts and having black or blackish-brown lores to chin and throat tipped with buff, grey or sandy colour – thus more resembling the males in head pattern. Not very clear!
Luckily, Shirihai & Svensson are more precise, stating that adult females are “almost identical to ad. f. (and young m.) libanotica Northern Wheatear, and contrary to previous descriptions nearly always lacks dark bib.” Black- or grey-throated females are thus considered rare. They go on to describe the upperparts as “largely pale grey (with limited sandy-brown suffusion) including on crown. Usually has duskier or almost blackish lores and ear-coverts; whitish supercilium often narrow and short, hardly extending to forehead […].”
Here’s a typical female in spring on the breeding grounds at Oukaimeden, and this picture on Afbid is from May at Ifrane. Adult females in autumn are said to be much as in spring but warmer.
The ageing criteria for first-winter birds, according to van Duivendijk, are as in Pied Wheatear [everyone knows these criteria by heart, right?!]: primary coverts with slightly frayed broad white fringes (ad autumn: often narrower and sharply bordered); primaries brown to brown-black often with pointed and worn tips; pale fringes to secondaries complete and cream-coloured; sometimes moult limit visible in greater coverts. There you go, just in case you’d forgotten. Ageing is thus largely based on moult limits, with first winter birds retaining juvenile primaries, primary-coverts and outer greater coverts, whereas in adults these are evenly fresh.
Back to Shirihai & Svensson, who state that first-winter males are “more female-like and rather feature-less, but still approaches fresh ad. m., having greyer upperparts and darker face with exposed black mottling especially on sides and lower throat; warmer below (Variation poorly known and requires more study)”, and that first-winter females have the “least contrasting plumage, with paler face pattern, and browner/duller ear-coverts.”
Let’s put the above to the test on some of our pictures from Senegal!
The following four photographs show three different birds from January; all are presumed to be first-winter males with varying levels of black extent on the face and throat. I initially assumed these to be adult males, but judging by the description of non-breeding males (by Shirihai & Svensson mainly) and compared to some of the pictures presented earlier on and those in Förschler et al., I now tend to label them as first-winter birds – mainly because of the overall sandy-coloured upperparts, mostly lacking grey tones. Again, keep in mind that ageing of these birds can be tricky and is not always possible! In the first bird, note the largely black throat and face appearing rather “smudged”, a fairly large white front merging into a clear whitish eyebrow extending well beyond the eye, and largely pale sand-coloured mantle and scapulars, the latter with a hint of light grey. The wings in the bird below appear relatively contrasted black and white, with extensive white fringes to the secondaries.
In this picture of the same bird, the greyish scapulars and some grey mottling on the back are more apparent:
This one taken earlier that same day in a different location shows a bird with less white on the chin and gives a very “cold” impression, though this is certainly exaggerated by the subdued early morning light. See also this picture of the same bird, as well as the second picture in this post (the one with spread out wings) which may well show the same bird, five weeks later in the same spot. Not sure about sex here – probably a male, but we probably can’t exclude a dark-throated female.
The same goes for this one from last December, taken by Wim van Zwieten near Podor. This bird also has fairly little black on the face but extensive pale fringes to greater and primary coverts as well as to secondaries, suggesting a first-winter male, though again not sure it can safely be sexed. These birds may be mistaken for Desert or Black-eared Wheatear (the black-throated form of which sometimes occurs in Senegal, though it’s probably rare), even by experienced birders.
The next bird gives a very pale impression, with uniform light sandy upperparts and a white lower breast, flanks, belly and vent. The upper breast are warmer tinged with a buffish wash extending down from the ear coverts, and so are the undertail coverts. The black or dark brown loral stripe is reminiscent of Isabelline Wheatear, but it has a narrow yet distinct supercilium both in front and behind the eye and has a different ‘jizz” and wing pattern than Isabelline. I’ve concluded that it’s a first-winter female, but as always would stand happy to be corrected. Either way, the very white underparts and pale upperparts stand out and should immediately point to Seebohm’s.
Of course, identifying a female or 1st winter bird in a vagrant context is something else. While not necessarily impossible, it will require a combination of characters as well as proper photographic documentation of underwing and tail pattern in particular. There have been at least two suspected birds in autumn in the UK but which could not be confirmed as definite Seebohm’s (read up more on these tricky birds here on Birding Frontiers). The first confirmed sighting for NW Europe was of a male in May 2017 in the Netherlands, a typical case of “overshooting” by North African or Mediterranean species during spring migration. Elsewhere in Europe, the species has been reported as a vagrant from Gibraltar, Italy, Malta, the Canary Islands.
Stay tuned for part II!
– Bram, with thanks to Frédéric, Simon, and to Wim for the use of his picture. And most importantly, a posthumous tribute to Robert Tovey who in a short few years made valuable contributions to our knowledge of birds in Mauritania, before unexpectedly passing away in September last year.
¹ Note (19.2.19): The only exception is actually a remarkable paper written by Mayaud in… 1951, in the French journal Alauda (19:88-96): Le plumage prénuptial d’Oenanthe oenanthe seebohmi (Dixon), in which the author provides a detailed description of birds in non-breeding plumage.
27/1/19, journée folle au Technopole
Il y a des jours comme ça!
Après une sortie déjà bien mémorable en compagnie de Simon le 24/1, lorsque nous observons entre autres des Canards chipeaux et un siffleur – tous deux des nouvelles espèces pour le site que Simon avait trouvées la veille – puis d’un Bécasseau de Temminck, Miguel et moi avons pris le temps de bien fouiller notre local patch dimanche dernier. Arrivés à l’aube sur les lieux, nous sommes repartis cinq heures plus tard avec pas moins de 111 espèces au compteur. Pas mal du tout, si l’on considère qu’une visite typique en hiver apporte généralement 70 à 80 espèces. De plus, la journée a été exceptionnelle aussi bien point de vue quantité – il devait y avoir facilement 4’000 oiseaux au Technopole ce jour-là – qu’en termes de qualité, avec plusieurs oiseaux rares et tout à fait inattendus.
Voici donc, in order of appearance, une sélection d’espèces rencontrées:
- Tourtelette d’Abyssinie (Black-billed Wood Dove): un juv. dans le coin nord-est du site était une petite surprise, cet oiseau n’ayant apparemment jamais encore été signalé auparavant au Technopole. En même temps, une Tourterelle vineuse (Vinaceous Dove) chantait dans le cordon boisé juste derrière: espèce numéro 233 pour le site!
- Hibou des marais (Short-eared Owl): on pensait qu’ils ne reviendraient pas un deuxième hiver de suite, mais les revoilà! Au moins deux de ces hiboux qui nous avaient gracié de leur présence l’hiver dernier, alors qu’un afflux important se déroulait en Afrique occidentale, étaient de nouveau présents sur leur dortoir favori dans un groupe d’acacias. Ils y avaient déjà été répéres fin décembre par deux observateurs, donc tout indique qu’ils resteront encore jusqu’à fin mars ou début avril avant de repartir pour nicher en Europe.
- Bécasseau de Temminck (Temminck’s Stint): déjà vu le 24/1, il ne nous a pas fallu beaucoup de temps pour le retrouver dans le même secteur, se nourrissant en compagnie d’autre bécasseaux. Du coup, nous avons pu observer en cette seule matinée tous les Calidris réguliers du pays: Bécasseau maubèche, cocorli, variable, minute et sanderling – pas mal, non? De plus, ce n’est apparemment que la deuxième obs du Temminck au Technopole, la précédente datant de mai 2015. A peine visibles sur la photo, les pattes jaunâtres en combinaison avec le dessus et la poitrine bruns uniformes sont typiques de ce petit bécasseau, trop souvent confondu avec le Minute. Il est ici tout à fait en marge de son aire de répartition régulière, étant bien plus commun en Afrique de l’Est (au Sénégal, il semble hiverner en petit nombre dans le bas-delta notamment).
- Chevalier à pattes jaunes (Lesser Yellowlegs): alors que je cherchais à mieux observer un pluvier posé parmi les nombreux Grand Gravelots (c’était un argenté…) je vois un chevalier suspect tout près de la piste, se nourrissant activement dans la vase: bec sombre assez court à base légèrement jaune, dessus gris-brun uni, dessous blanc, croupion blanc, et surtout: des pattes jaunes flashant… encore un Tringa flavipes! Serait-ce le même que celui vu l’hiver dernier en février, peut-être même l’oiseau déjà vu en août 2015 et janvier 2016, voire également à Yene en novembre 2017?? En tout cas cette régularité d’observations est intriguante. Comme pour les bécasseaux, nous avons pu observer ce jour tous les chevaliers réguliers au Sénégal, car en plus des habituels des lieux il y avait également deux ou trois Chevaliers arlequins, peu communs ici (Spotted Redshank). En plus de quelques photos relativement nettes pour une fois, on a même réussi à faire un enregistrement de son cri, à écouter ici.
- Goéland de la Baltique (Baltic Gull): probablement la plus grosse surprise du jour, on a été bien étonnés de voir un adulte on ne peut plus typique de cette sous-espèce nominale du Goéland brun: en comparaison directe avec ce dernier, notre oiseau s’en distinguait nettement par sa taille plus petite (sans doute s’agissait-il d’une femelle), son manteau très sombre, presque noir même, et surtout une projection primaire importante lui conférant un aspect bien plus élégant et plus allongé (un peu comme un Pluvier bronzé comparé au Pluvier argenté!). En vol, les ailes longues et plutôt étroites, avec très peu de blanc au bout des primaires externes, étaient frappantes. Malheureusement après un envol général l’oiseau n’a pas été revu, donc pas de photos à l’appui… Notre première obs au Sénégal, ce taxon est néanmoins connu pour hiverner en effectifs très modestes sur les côtes d’Afrique de l’Ouest (quelques individus? pas sûr même que ce soit un visiteur annuel). Sa présence ici, loin de ses quartiers d’hiver réguliers en Afrique de l’Est et l’ocean indien, a été confirmée grace à quelques lectures de bagues notamment en Gambie. Egalement présent dans le tas de centaines de goélands, au moins un Goéland leucophée (Yellow-legged Gull) de 1er hiver, un individu au manteau très clair.
- Mouette mélanocéphale (Mediterranean Gull): une dizaine d’oiseaux au moins, soit un peu plus que d’habitude. Comme toujours, l’essentiel des effectifs hivernants est composé d’oiseaux de premier hiver. Pas vu d’oiseaux bagués cette fois-ci, mais on vient de me signaler – merci Renaud – que “RV2L” vu l’hiver dernier a été observé il y a tout juste quelques jours au Portugal.
- Canard chipeau (Gadwall): les trois individus trouvés par Simon le 23/1 étaient toujours présents, bien que pas forcément faciles à répérer dans le tas d’anatidés, bien plus compact que quelques jours plus tôt: avec près de 400 Souchets et autant de Sarcelles d’été, cela fait du monde à fouiller… Il s’agit a priori de la première donnée sur la péninsule du Cap-Vert de cet hivernant rare au Sénégal, dont les quelques observations proviennent sauf erreur toutes du bas-delta. On n’a pas vu la femelle de Canard siffleur (Wigeon) cette fois alors qu’elle était assez bien visible les 23-24/1; là aussi il s’agirait d’une première pour le Technopole. Cela fait donc pas moins de 4 ajouts à la liste, et cela en moins d’une semaine.
- Mouette de Franklin (Franklin’s Gull): encore une obs de ce laridé néarctique! C’est presque devenu banal ici… Un peu loin comme souvent, au repos dans un groupe de Goélands railleurs et Mouette rieuses – bien nombreuses ce jour – j’ai tout de même fait une photo-preuve où l’oiseau, au manteau gris sombre et au capuchon déjà en grande partie noir, est tout juste reconnaissable au milieu du groupe. Entre la photo du Temminck et celle-ci, je ne sais pas laquelle gagnera au concours de la photo la plus pourrie du jour…
Pour le reste, voir notre checklist eBird (merci Miguel!)
Une fois de plus, le Technopole confirme sa position de haut-lieu de l’ornithologie sénégalaise, et de hotspot urbain tout à fait exceptionnel. A voir ce que nous apporteront les prochaines visites!
Description of a new species of Square-tailed Drongo
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.
An Audio Guide to the Birds of Senegal / Un guide audio des oiseaux du Sénégal
Introducing what will hopefully be a useful resource to some readers out there and more generally for birders visiting Senegal or The Gambia!
Until recently, the only comprehensive sets of sound recordings of West African birds were limited to CD collections that are only available commercially, often at a high price – and some are no longer for sale. The most comprehensive of these is the African bird sounds CD set by sound recorder pioneer Claude Chappuis, published nearly 20 years ago accompanied by an extensive booklet, covering 1043 species. As Françoise Dowsett-Lemaire wrote in her extensive review in the African Bird Club Bulletin, this work marks “a landmark in African bioacoustic publications, one that will (and must) be widely used in the field and which will remain unsurpassed for many years to come.”
The only other relevant audio guide for West Africa published so far is the Bird Song of The Gambia & Senegal CD set produced by Cive Barlow and colleagues in 2002, covering 265 species, but it is no longer available it seems; similar initiatives have covered e.g. East Africa (East African Bird Sounds by Brian Finch) and Zambia (Bob Stjernstedt’s Sounds of Zambian Wildlife).
But who still uses CDs? Digital field guides under the form of Android apps or e-books have made their appearance in recent years, and these often contain a range of sounds for each species – Borrow & Demey’s Birds of Senegal and The Gambia being the most comprehensive, but it’s only available as an Apple Book for iOS devices.
And then there’s xeno-canto.
We’ve often referred to this amazing resource on this blog, but what exactly is xeno-canto? The open-access initiative called the xeno-canto project was established in 2005 by Xeno-canto Foundation, aiming to popularise bird sound recording worldwide, improve accessibility of bird sounds, and increase knowledge of bird sounds. Initially focused on the Neotropics, it soon expanded to all other world regions, including Africa in 2008.
The collection continues to grow substantially: at the time of writing there are 31,275 recordings of 1,974 species for Africa (just over two years ago, in October 2016 there were “just” 19,813 recordings of 1,841 species). Needless to say, much more than any of the audio guides mentioned above, “XC” truly revolutionised the way birders and researchers alike can freely share, access, and use sound recordings. All for free.
Now for the audio guide:
It’s actually a simple xeno-canto “set”, available through this link:
The selection of 746 sound recordings included in this set cover 450 species, or 66% of the total number recorded in Senegal (677). This is about three quarters of the 600 or so regular species in the country, i.e. excluding vagrants and birds with uncertain status. Vagrants as well as scarce species that typically do not usually call or sing when encountered in Senegal (e.g. Honey Buzzard), or otherwise silent non-breeding visitors (e.g. harriers and other raptors, Palearctic ducks, storks, seabirds), were not included in the set.
There are of course still a few missing species, including several for which there are no recordings at all available on xeno-canto, most notably White-crested Tiger Heron, Beaudouin’s and Brown Snake Eagles, Denham’s Bustard, Cassin’s Honeybird, African Hobby, Sennar Penduline Tit and Crimson Seedcracker. Hopefully these will be added in the near future, in which case I will of course add them to the set. Likewise, for others such as Greater Painted-Snipe (no recordings from Africa on xeno-canto!), Red-headed Quelea and a few other scarce songbirds there are no decent recordings.
The sounds included in this set were for the main part recorded in Senegal or The Gambia, and where not possible I tried to prioritise recordings from neighbouring countries. This is relevant for particular subspecies that show vocal differences between taxa, but also because there may be regional dialects within populations. I chose to include my own recordings where possible, simply because I’m in full control of these and can make sure that sound types, subspecies and other attributes are appropriately registered, and these sounds definitely won’t be deleted.
Do keep in mind that many species have a large repertoire of call types – advertising song, territorial song, subsong, contact call, flight call, warning calls, etc. – and not all are represented in this collection. Also, some species exhibit a great deal of individual variation, and then there’s those that weave in mimicry of other species such as robin-chats. Additional details on behaviour, habitat, background species and other relevant information are provided for many of the recordings.
The recording set is accessible to anyone – no app, no account needed – from any internet -enabled device, while recordings can be downloaded as mp3 files for offline use (but please… take it easy on the “tape-luring”, i.e. attracting birds with playback of their calls or song as a means to see the bird). Thank you xeno-canto.
Please do note the Creative Commons license which stipulates that material can be freely redistributed with modifications and for non-commercial purposes, with acknowledgement of authorship (or “Attribution-NonCommercial-ShareAlike”, CC BY-NC-SA). Some recordings by other recordists may be published under a slightly different CC license.
Using the audio guide is pretty easy:
- Go to this URL: www.xeno-canto.org/set/2242
- Browse the list of species, by searching on the vernacular or scientific name (note that xeno-canto is available in many languages: scroll to the bottom of the page to switch to another language). See sample screenshot of a search for sunbirds here.
- Change the format of the list if a format other than “Concise” is preferred (Detailed, Codes, Sonograms)
- Download recordings as mp3 files, by clicking the download button
- For each species, access additional sounds, range map, and links to external resources (AVoCet, Macauley Library by the Cornell Lab, HBW, BirdLife, etc.)
Finally, while writing about bird sound recording I can’t not mention The Sound Approach collective which has done so much in recent years to put the importance of bird vocalisations in identification and taxonomy on the forefront, and to firmly establish birders’ interest in sound recording. It’s only after reading their highly acclaimed The Sound Approach to Birding (2006) that I started to better understand bird vocalisations and that I became a fairly active sound “recordist”. Still one of my favourite bird books! Maybe one of these days I’ll write up something about sound recording and sound birding. After all, up to 80% of birdwatching is actually… bird listening!
Une compilation de sons d’oiseaux du Sénégal, ce “jeu” xeno-canto contient des enregistrements de chants et différents types de cris pour une sélection d’espèces, soit 746 enregistrements couvrant 450 espèces. Les visiteurs rares et les migrateurs qui sont généralement silencieux dans les quartiers d’hivernage ne sont pas inclus. Il manque bien sûr plusieurs espèces, mais on espère que des enregistrements pour celles-ci deviennent prochainement disponibles et on les ajoutera alors au jeu. De même, plusieurs espèces existent bien dans la collection xeno-canto mais il n’y a pas actuellement des enregistrements de bonne qualité.
La plupart des enregistrements proviennent du Sénégal ou des pays voisins, et pour l’essentiel il s’agit de mes propres prises de son. A noter que de nombreuses espèces ont un large répertoire de types de sons (chant territorial, “subsong”, cri de contact, cri de vol, cris d’alarme, etc.), et que toutes ne sont pas représentées dans cette collection. En outre, certaines espèces présentent de nombreuses variations individuelles, puis il y a celles qui imitent d’autres espèces telles que les cossyphes. Des détails supplémentaires sur le comportement, l’habitat, les espèces en arrière-plan et d’autres informations pertinentes sont fournis pour de nombreux enregistrements.
Ce jeu d’enregistrements est librement accessible à chacun – pas besoin d’installer d’application, pas besoin de compte utilisateur – et ce depuis n’importe quel appareil avec connexion internet ; les prises de son peuvent être téléchargés en format mp3 pour utilisation hors connexion (mais attention de ne pas abuser de la repasse pour faire sortir les oiseaux !).
Veuillez noter la licence Creative Commons qui stipule que le matériel peut être librement redistribué avec des modifications et à des fins non commerciales, avec mention de l’auteur (ou “Attribution-NonCommercial-ShareAlike”, CC BY-NC-SA). Certains enregistrements d’autres auteurs peuvent être publiés sous une licence CC légèrement différente.
L’utilisation du guide audio est simple :
- Allez à la page www.xeno-canto.org/set/2242
- Parcourez la liste d’espèces, en cherchant sur le nom français ou scientifique (à noter que xeno-canto est disponible en plusieurs langues : allez jusqu’au bas de la page pour modifier la langue). Capture d’écran en guise d’exemple d’une recherche sur les souimangas ici.
- Modifiez le format de la liste si vous préférez un format autre que “Concis” (Détaillé, Codes, Sonogrammes)
- Téléchargez les enregistrements en format mp3, en cliquant le bouton de téléchargement
- Pour chaque espèce, accédez à des sons supplémentaires, la carte de répartition, et des liens vers des ressources externes (AVoCet, Macauley Library par the Cornell Lab, HBW, BirdLife etc.)