Quick post to report yet another American vagrant, after the Franklin’s Gull from last Saturday and the Lesser Yellowlegs from just a week ago, both at Technopole.
This morning at Palmarin in the western Saloum delta, I found an American Golden Plover (Pluvier bronzé), likely a second year bird, feeding on the edge of a shallow lagoon together with a few other waders. It’s almost getting a bit of a standard spring sighting here in Senegal: this is the third consecutive year with records in April, and the species has been near-annual since 2012. Prior to this only three records were known, though it’s not clear whether this reflects a true increase in the number of “AGPs” that make it to West Africa or just a result of increased observer coverage – probably the latter. The Palmarin bird brings the total to 14 records involving at least 17 birds.
As can be seen in my hazy pictures below, the bird stood out mainly thanks to its very white supercilium extending behind the ear coverts, the dark smudge across the breast, and of course long wings extending well beyond the tail tip. As it flew a short distance, I could clearly see the greyish underwing.
The same small lagoon just north of Ngalou village also held quite a few Slender-billed Gulls and several Caspian, Royal and Sandwich Terns (+ one Lesser Crested), six Avocets, three Black-tailed Godwits and a few other waders, though generally there aren’t loads of birds around at the moment (which is all relative of course: far out in the lagoons, there were hundreds of Little Stints and other small waders, just very far out… and at Diakhanor about a dozen Bar-tailed Godwits were seen).
Unlikely that anyone would go out to twitch the plover, but you never know so here’s a Google Maps link to the precise location where I saw the bird.
Besides the waders, a few remaining Lesser Black-backed and Audouin’s Gulls as well as two small groups of Barn Swallows, a couple of Yellow Wagtails and a few Western Olivaceous Warblers were the only other northern migrants still around.
Below are a few pictures of other species seen during the 24 hours we spent at Palmarin.
Let’s see if this spring any American Golden Plovers turn up at Technopole again…
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.
This is the second part of a review of what we know about Seebohm’s Wheatear in Senegal, the first part covering its identification in autumn and winter. As already mentioned in that piece, this species has a pretty restricted range, breeding only in the Middle and High Atlas of Morocco and Algeria, generally above 1500 meters asl. Until fairly recently it was considered more of an altitudinal or short-range migrant, but it’s clear now that it’s actually a medium-range “total” migrant (i.e. all populations tend to migrate away from breeding grounds – not surprising given that much of it is covered in snow during winter!).
The non-breeding range of “Black-throated Wheatear” is given by the Handbook of the Birds of the World Alive as “West Africa (mainly SW Mauritania and Senegal to W Mali, occasionally in S Morocco)”. However, the HBW range map is rather incorrect: all regions of Senegal and Gambia and even Guinea-Bissau are included, although as far as I know the species has never been reported from the latter two countries. The same applies to Guinea and Burkina Faso which are also partly included in the range. Let’s hope that this will get corrected soon – the HBW species page of this newly recognised taxon (formerly considered a subspecies of Northern Wheatear) was only fairly recently published online, and is obviously work in progress.
The winter distribution in Shirhai & Svensson (2018) on the other hand seems more accurate, though perhaps a bit too conservative in that it includes only a very small part of western Mali. Judging by the data available on the Biodiversité Al-Maghrib portal, it’s clear that some birds winter may further to the north, much closer to the breeding grounds. Indeed, there are several observations from southern Morocco and from the Western Sahara from December-February, and it’s easy to imagine that it’s rather beneficial for these birds if they can avoid crossing the Sahara. There are also a few recent records from the Adrar region in Mauritania, e.g. this one and this one by Wim van Zwieten and friends seen at the end of December last year, suggesting that this area may also be part of the species’ winter range.
The Shirihai & Svensson map is most likely largely based on a paper on Seebohm’s Wheatear in West Africa by Förschler and colleagues (2008), which to date gives the most comprehensive overview of our knowledge of its wintering grounds in the Sahel, following field work they undertook in western Niger, Mali and Mauritania combined with a review of published data. They note that “although seebohmi was previously thought to be a resident or only a partial migrant by some authors, it is now considered a true migrant, with the majority of the population leaving Morocco and Algeria in winter. Browne (1982) found a major wintering area, roughly estimated to hold at least 50,000 individuals, in the eastern part of south-west Mauritania […].” They also refer to three more southern records from Djoudj NP (mentioned by Rodwell et al. 1996), and conclude that “the majority of this taxon’s population appears to winter immediately south of the Sahara, in the Sahel zone of southern Mauritania, northern Senegal and north-west Mali between 15–18°N and 09–16°W, although its wintering grounds may range even further east, including parts of central Mali.”
Away from its regular range, there are a few scattered records of Seebohm’s Wheatear in the Mediterranean and one from the Netherlands (April 2017), plus a couple of possible sightings from the UK: Italy (one in April 2014 in Sardinia), Gibraltar, Malta, Tunisia, and several times in the Libyan desert and even once from western Egypt. It’s also on the list of the Canary Islands, and apparently also reported from Cameroon, as per Arnoud B. van den Berg on DutchAvifauna,nl). So it’s definitely a species to have on one’s radar when encountering an unusual wheatear in western and southern Europe; I can imagine that one day a fine male will show up in spring in the Camargue, the Spanish coast or on the Balearic islands – or pretty much anywhere north of its range for that matter.
Status & Distribution in Senegal
In Senegal, in addition to the aforementioned Djoudj records, the species has been reported from the Richard-Toll, Dagana, Podor and Ndioum areas, and at least once from the lower Senegal valley, on 2.3.09 by Frédéric Bacuez, Ornithondar. Of course, Frédéric had already provided a comprehensive overview of the distribution of Seebohm’s Wheatear in Senegal, more precisely in this blog piece from 2016. The Morels mention several spring records (13 March – 14 April) in the middle Senegal valley as far upstream as Salde, plus one from early January 1981 near Richard-Toll seen by Alan Tye. They also report the presence on two occasions some 60 km south-east of Richard-Toll. But that’s about it: not an awful lot of records to go by! It’s quite possible that it may also be found at least occasionally in the Ndiael reserve, around lac de Guiers and into the Ferlo (e.g. Six Forages). These sites are not very often visited by birders or ornithologists, and the recent records that I came across are typically from Richard-Toll and the Podor areas, with the exception of a first-winter male at Saot (ENE of Touba), seen by J-F Blanc in January 2010. No records are known from the Grande Côte, though it’s not impossible of course that the species shows up here at least from time to time.
As can be seen from the map below, northern Senegal is on the southern edge of the species’ winter range, which may explain why most birds seen here appear to be first-winter birds. Adults, and in particularly males, may well winter further north including on the other side of the Sahara as mentioned earlier. Though it’s certainly not rare, the species seems to be nowhere common across its range in Senegal. When we toured the middle valley in January last year, we saw the species in small numbers (1-2 ind. per site) at three different locations: Bokhol, in a sparsely wooded dune depression east of Ndiayene Pendao, and at Gamadji Sare. Some sites such as the Bokhol “fores” appear to be pretty reliable, and a dedicated search would probably reveal other sites where they may be regular and maybe even locally common; in 1973 Seebohm’s Wheatear was said to be “the most common [wheatear] species in winter in the Podor region”, while Sauvage & Rodwell refer to a total of 18 ind. seen at three locations in February 1993 in the Podor atlas square. There may of course be annual variations, possibly depending on any cold spells in north-west Africa, but obviously more data are needed (as usual!).
The majority of sightings are made between December and early March, but this is when most birders visit the country and it’s likely that Seebohm’s is regularly present at least from (mid?) October and up to early April. In Nouakchott, it’s been seen as early as the end of September (see Rob Tovey’s eBird checklist with two pictures of a fresh autumn male), but when I last visited the Podor region in early October 2018 I did not see any birds on the sites that held several wintering individuals back in January, so it seemed that they had not arrived yet at that time.
In short, the main wintering area of Seebohm’s Wheatear lies in Mauritania, northern Senegal and NW Mali, on the edge of the Sahara and in the northern Sahel zone. It is a regular winter visitor to northern Senegal, being scarce locally fairly common along the middle Senegal Valley, from October/November to March or early April.
The main winter range in West Africa should look something like this, though it possibly extends a bit further south in Senegal and further east along the Mauritania-Mali border. And as mentioned already, some birds may winter in southern Morocco and in the adjacent Adrar region of Mauritania, as well as along the coast north of Nouakchott: the below map may well need to be adjusted as such – comment welcome, as usual.
While its habitat in summer essentially corresponds to Alpine meadows with rocks and stone structures, usually devoid of any trees, in winter the species may inhabit light Sudano-Sahelian woodland, at least along the Senegal valley. Elsewhere, particularly further north in Mauritania, it probably occurs mostly in more open habitat. The Bokhol forest just east of Dagana seems to be a reliable place to find Seebohm’s Wheatear: it is comprised of a mix of Acacia, Balanites aegyptiaca and other trees growing on sandy soil with little or no undergrowth. Indeed, most of the winter range of the species is heavily overgrazed anyway, and away from the floodplains there is generally very little vegetation cover… the picture below gives an impression of the the sad state of what remains of northern Senegal’s “forests” – a very liberal concept here at these latitudes.
We’ve also encountered the species on several occasions at Gamadji Sare, where part of the area is also made up of light woodland, not dissimilar to Bokhol, though less mature. Some birds here were seen in more open areas, including right by the bank of the Doué river where this picture was taken:
In much of its range, the species is cohabiting with Northern (ssp. oenanthe and probably also libanotica), ‘Greenland’ (leucorhoa) and Isabelline Wheatear, probably locally also with Black-eared and Desert Wheatears though the latter two species are typically very scarce in Senegal it seems. Heuglin’s Wheatear is also possible in winter in northern Senegal, but it’s much rarer and was added to the national list only recently, following a record in the Djoudj NP in January 2007 (and was found breeding even more recently in the Kédougou region).
A brief etymology¹ of Seebohm’s Wheatear
The HBW Alive lists this taxon as Black-throated Wheatear, another rather boring and unimaginative English name. I’ll stick to Seebohm’s. Alternatively, Atlas Wheatear would be a pretty good one as it nicely highlights the restricted breeding range of the species; this name is already in use in Spanish and German, and no doubt in other languages.
But actually, why Seebohm’s Wheatear? Tim Birkhead – author of (at least) two great books, The Wisdom of Birds and Bird Sense – wrote about Henry (or should it be Harry?) Seebohm, a 19th century British industrial and ornithologist, most famous for his fieldwork in Siberia. Which doesn’t really explain why our wheatear from the Atlas goes by his name… enter Charles Dixon, who formally described the taxon in 1882 based on a specimen from the Algerian Atlas. A contemporary of Seebohm, Dixon collaborated on Henry Seebohm’s British Birds opus, so I think it’s safe to assume that Dixon named his newly described chat in honour of his friend.
The term “wheatear” apparently comes from “white” and “arse”, referring to the prominent white rump found in most species.
¹ Etymology is the study of the origin of words and the way in which their meanings have changed throughout history. Applied to vernacular and scientific bird names, this comes down to retrieving the origins of these names.
Thanks once again to Frédéric Bacuez and Wim van Zwieten, and now also to Jérémy Calvo for making available some of their pictures from Mauritania and Morocco
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.
A visit to Popenguine nature reserve a couple of weeks ago quickly turned into a exciting few hours watching a good variety of raptors – something we’re not much used to in this part of Senegal, where there are few sites that are good for raptors, and most of the time anything else than a Yellow-billed Kite, Osprey or Hooded Vulture will qualify as a good record. Here’s a short overview, in order of appearance!
As always, several Ospreys were to be seen in the reserve; a few birds usually spend the night on the mighty baobabs that dot the Popenguine savanna, and all day long Ospreys can be seen flying around the cliffs or fishing out at sea. Later that same day at the lagoon just south of Toubab Dialaw, we had a good count of some 29 birds, all visible at the same time (Balbuzard). Popenguine of course also had a few Yellow-billed Kites patrolling the area (Milan à bec jaune).
As we were looking for a Common Rock Thrush we’d briefly spotted on a ridge ahead of the footpath, we noticed first an immature Peregrine Falcon flying around, then a European Hobby – the latter a scarce migrant through Senegal so always a good find. Hobby was already seen at Popenguine around the same time last year by Miguel. This time round it looked like it was an actively migrating individual, just like a Common Kestrel that briefly made an appearance shortly after (Faucons pèlerin, hobereau et crécerelle).
Next up was a Marsh Harrier circling in the distance, again probably a bird on its way to wintering grounds further south (Busard des roseaux). I’ve always thought that Popenguine would be a fairly strategic site to look for actively migrating raptors and other birds. Should be interesting to spend a few days here in October-November and February-March!
This Short-toed Eagle on the other hand was probably one of the 2-3 birds that typically spend the winter in the area around Popenguine and Guereo.
Far less expected than the previous species was an African Hawk-Eagle, spotted by Gabriel as it arrived from the north-east and made its way towards the cliffs, at one point circling together with a couple of Ospreys. Initially we weren’t quite sure about its identity and tentatively id’d this bird as a Bonelli’s Eagle, wondering whether a juvenile African Hawk-Eagle could be ruled out, and were a bit puzzled by the very pale appearance of this eagle. Luckily I managed a few record shots, a bit distant and hazy but they should do the trick. The plumage seemed to still be within the variation of worn juvenile Bonelli’s Eagle, but moult should not start until the second year and this bird shows clear moult contrast on with fresh inner primaries growing. Simon was the first to point out, after this post was originally published, that it looked more like African Hawk-Eagle. I eventually sent out the picture for comments, and Dick Forsman kindly responded, confirming that it’s an African Hawk-Eagle: “It is overall lighter below, the juvenile remiges (primaries + secondaries) are too light and too poorly barred below for a juv. Bonelli’s and the replaced inner primary shows just a dark tip without any further barring. Note also the translucent primaries in the images with blue sky, another pro-spilogaster feature.” Thanks Dick! (post updated Dec. 27)
African Hawk-Eagle is reasonable common it seems through the southern half of Senegal, and is a classic sighting e.g. in the Niokolo-Koba area. There are some records from the Saloum delta and even from the middle Senegal valley (as per Morel & Morel and Sauvage & Rodwell), but as far as I know this is the first from the Petite Côte.
I’m still hoping to see Bonelli’s Eagle one day in the Djoudj, Trois-Marigots or elsewhere in the Senegal valley, the only area with more or less regular records in winter (mainly by Frédéric, who year after year has documented the presence of a few birds around Saint Louis and who nicely summarised the current knowledge about this scarce species in West Africa, in this post on Ornithondar).
After we’d reached the top of the cliffs, next up was this Eurasian Griffon which appeared to be actively migrating along the coastline, just like a second bird we’d see a couple of hours later that same morning near Yène.
Barely a few minutes later, Gabriel strikes again with a young Lanner making a brief appearance, just as we were heading back towards the reserve entrance (Faucon lanier). That’s four species of falcons, not bad! In previous years we’ve also had Barbary Falcon near the cliffs, and surely Red-necked Falcon and Grey Kestrel must also occur at least occasionally, while in the wet season it may be possible to encounter African Hobby.
We thought we’d seen pretty much everything when at the last minute a Shikra was seen dashing over the pond (all but dry!), bringing our morning’s total to 11 birds of prey.
Besides all these hooked beaks, as always the nature reserve held quite a few other good bird, such as Gosling’s Bunting, Green-winged Pytillia, Sahel Paradise-Whydah, Blue Rock Thrush, and Northern Anteater Chat. In the end we saw two different Common (=Rufous-tailed) Rock Thrushes, a scarce migrant in Senegal, see this post on our first encounter with the species, in February 2016 at… Popenguine! Also a decent flock of Pallid Swifts and a few White-throated Bee-eaters, both pretty good bonus species, while two Pygmy Kingfishers including at least one dark-billed juvenile provided proof that the species is breeding here.
Complete eBird checklist available here.
The bird list for the Popenguine reserve now stands at some 198 species, at a minimum that is: I listed more than 20 other species as being most likely present, but which apparently remain to be confirmed. More on that over here.
Oh and then there were the butterflies – pure magic! Thousands and thousands of butterflies everywhere, especially along the track up the cliffs. With every footstep, small clouds of butterflies would explode, while a constant stream of butterflies was passing by the cliffs. Our visit clearly took place during peak migration season of Painted Lady which were the vast majority, and to a lesser extent some pieridae. And loads of dragonflies! Difficult to capture on camera but if you look carefully at the image below you’ll get a bit of a sense of what I’m trying to explain here.
Why would two Portuguese, a Mauritanian, a Cape-Verdian, a French, an American and a Belgian set off on a boat trip one morning in October? Seabirds of course! With Gabriel in town, Bruce over from the US, Miguel and Antonio as motivated as ever to get out of the office and to have some of their BirdLife colleagues strengthen their seabird id skills, it was time to organise our now annual autumn pelagic, on October 1st.
Conditions were perfect to get out on our small boat (organised through Nautilus Diving: merci Hilda!) though probably a bit too calm for active seabird migration. We chose to head straight west to the edge of the continental shelf, rather than try the “trawler area” off Kayar as this is quite a bit more distant from Ngor. Needless to say that expectations were high as is always the case during these rare opportunities to get close views of the treasured tubenoses – storm petrels, shearwaters – skuas and maybe some Grey Phalaropes or Sabine’s Gulls.
A Manx Shearwater zooming past the boat was one of the first pelagic species we got to see, followed by quite a few Sooty Shearwaters (Puffin fuligineux).
Further out, Wilson’s Storm Petrel became the dominant species, with a few dozen birds seen – and probably many more that went undetected – particularly around the upwelling area. Almost all were obviously actively migrating, and we managed to get some good views of several of them as they zoomed past our boat. Of course, several storm petrels remained unidentified, but we did manage to get decent views of at least two European Storm Petrels (though alas no pictures!). The toes projecting beyond the tail that are diagnostic of Wilson’s are more or less visible on the pictures below.
Up next: skuas, or jaegers as our American friends call them. We didn’t see many, with just three Pomarines and just as few Arctic Skuas, as well as an obliging Long-tailed Skua. The latter was an interesting bird that we aged as a third-summer moulting into third-winter plumage. It briefly joined two Pomarine Skuas (second-year birds?) allowing for nice comparisons of size and structure.
Rounding up our seabirds is this Red (Grey…) Phalarope (Phalarope à bec large), the only one we saw during the trip but somehow Bruce managed to get a picture:
As seems to be quite often the case during these pelagic trips, some landbirds were also encountered, in our case European Turtle Dove (Tourterelle des bois) of which we twice saw singles migrating over the ocean (in October 2016, the PAOC pelagic recorded at least three species of passerines, including a migrating Bluethroat). One of our doves had a very worn and messy plumage, probably a moulting young bird:
Our complete eBird checklist, expertly compiled by Miguel, can be found here. We really ought to add the Osprey that can just about be seen sitting on top of the Almadies lighthouse, but which was noticed only later on this neat picture by Bruce of the lighthouse – Africa’s westernmost building, constructed some time in the 19th century (precise date seems unknown?) on a reef that lies just off the Pointe des Almadies.
Many thanks to Antonio and Bruce for sharing their pictures!
Depuis un peu plus de deux mois on a repris nos habitudes au Calao de Ngor cet automne (ai-je vraiment arrêté depuis l’an dernier?), pour voir ce que donne le cru 2018 pour ce qui est de la migration d’automne des oiseaux de mer. Le printemps avait déjà été pas mal, avec entre autres de beaux passages de Sternes voyageuses et de Dougall, de Mouettes de Sabine, et quelques espèces plus rares comme le Fou à pieds rouges, le Puffin de Macaronésie / de Barolo ou encore le Puffin majeur. Ayant eu un peu plus de temps libre et moins de voyages que d’habitude, j’ai donc repris le suivi régulier depuis fin juillet. J’étais curieux notamment de mieux suivre les mouvements en août et septembre, et finalement j’ai un peu mieux pu suivre ces deux mois que l’an dernier: entre le 30/7 et le 30/9, j’ai pu assurer une présence lors de 41 jours, pour environ 55 heures de suivi (2017: 40.5 heures sur 31 jours). A propos de notre suivi de l’an dernier, un article sur le suivi de la migration en 2017 est en cours de rédaction et sera partagé ici en temps voulu!
Les années se suivent mais se ne ressemblent pas: certaines espèces sont visiblement plus communes certaines années, et les conditions météo varient pas mal également. Ainsi, le mois d’août 2018 a été marqué par plusieurs jours de vent favorable (= vent soutenu de l’ouest a nord-ouest), et notamment le Labbe à longue queue a été bien plus nombreux a passer devant les cotes dakaroises qu’en 2017 et 2016. Idem pour les Phalaropes à bec large qui comme le labbe voient eux aussi s’établir un nouveau record journalier.
Comme d’hab’, voici donc une liste comme toujours un peu longue et ennuyeuse, agrémentée de quelques photos d’archives.
Océanite de Wilson (Wilson’s Storm Petrel): au moins 159 oiseaux sont vus entre le 31/7 et le 23/8, avec un max. de 105 en 30′ de suivi le 13/8.
Puffin du Cap-Vert (Cape Verde Shearwater): 97 ind. passent le 11/8 en 2h40′, suivi d’un isolé sur place le lendemain et deux oiseaux le 20/8.
Puffin fuligineux (Sooty Shearwater): comme en 2017, les premiers oiseaux apparaissent des les premiers jours de septembre, mais cette année les effectifs restent très modestes jusqu’à fin septembre: seulement 87 oiseaux du 2/9 au 30/9 alors que dans la même période l’an dernier il en passent 393 pour un effort comparable.
Puffin des Anglais (Manx Shearwater): seuls six oiseaux sont détectés pour le moment, sans doute en raison de l’absence de bonnes conditions météo pour les puffins courant septembre, mois qui devrait marquer le pic du passage de cette espèce.
Puffin “d’Audubon” (Audubon’s Shearwater): à l’inverse, ce puffin généralement très pélagique a été vu bien plus que ces dernières années, avec 19 oiseaux pour le moment. Le premier oiseau passe le 11/8, puis le lendemain c’est un Puffin de Barolo qui est observé en migration active, assez près du rivage permettant son identification. Encore un Barolo ou Macaronésie le 28/8, et le 17/9 il y en a pas moins de 14 qui défilent en deux heures dont quelques groupes de 3-4 oiseaux migrant ensemble. Encore deux le 28/9, et peut-être qu’il en suivra encore quelques-uns dans les semaines à venir.
Fou de Bassan (Northern Gannet): un oiseau de 1ère année passe le 23/9 déjà (2017: premier le 18/9, puis un seul en octobre avant le véritable debut du passage début novembre).
Fou brun (Brown Booby): deux le 26 (un adulte et un imm.) et un imm. les 28 et 29/9 étaient probablement des oiseaux locaux en excursion de pêche depuis les îles de la Madeleine.
Comme je le disais dans l’intro, l’une des surprises de cette saison a été le passage important de Phalaropes à bec large (Red Phalarope) en août: alors que je n’avais noté aucun oiseau avant le 11/8, ce jour-la j’en dénombre pas moins de 825 en 2h40′ de suivi le matin, plus encore 35 en 40′ le soir – apparemment un nouveau record journalier pour le Sénégal, à en croire les chiffres a notre disposition. Plus rien les jours suivants, jusqu’au 18/8 lorsque quelques 65 oiseaux passent en deux groupes – toujours aussi difficiles à estimer! – 37 le 20/8, etc. jusqu’au 2/9. Encore 55 le 17/9, pour un total tout à fait honnête de 1256 oiseaux. Sans doute que plusieurs milliers sont passes au total, loin au large ou invisible entre les vagues. Parmi les autres limicoles, retenons le Courlis corlieu (Whimbrel) avec 415 ind., deux Barges rousses (Bar-tailed Godwit), 28 Huîtriers pies (Oystercatcher) dont 13 ce matin, deux groupes de Bécasseaux maubèches (Red Knot), quelques Tournepierres (Turnstone), un Combattant varié (Ruff), deux Grands Gravelots (Common Ringed Plover) et quelques Chevaliers gambettes et guignettes (Common Redshank & Common Sandpiper).
Mouette de Sabine (Sabine’s Gull): un avant-coureur passe le 30/7 déjà, constituant peut-être bien la premiere observation de juillet pour le site. Passage plus ou moins régulier bien qu’en effectifs très faibles – comme il se doit en août et septembre – du 11 au 22/8 lors d’une période de vents favorables, puis sept le 1/9 et en tout 31 en 2h45 de suivi les 17-18/9. Encore cinq le 24/9 puis plus rien depuis! On attendra donc le gros passage de la deuxième moitie d’octobre pour cette espèce. Peu d’autres laridés pour le moment, mais tout de même à signaler un Goéland leucophée adulte (ou presque) le 23/8.
- Sternes & Guifettes
Sterne naine (Little Tern): 129 individus pour le moment, soit le même ordre de grandeur que l’an dernier à la même periode (idem pour la Sterne caspienne (Caspian Tern), avec 27 oiseaux au compteur).
Guifette noire (Black Tern): avec 4402 oiseaux, c’est pour l’instant la deuxième espèce la plus nombreuse: pas mal d’oiseaux vers la mi-août, puis petit max. horaire de 460 le 18/9. Au moins une Guifette leucoptère (White-winged Tern) est identifiée le 11/8.
Une Sterne bridée (Bridled Tern) est vue en vol vers le NE le 9/8, suivi d’un individu vers le SW deux jours plus tard, et deux oiseaux (adulte et juv.) sur place le 22/8 – probablement des oiseaux ayant niche aux iles de la Madeleine ou au moins 3-4 couples ont été vus en juillet dernier. Plus surprenante, une jeune Sterne fuligineuse (Sooty Tern) passe vers le SW le matin du 17/9, ma première obs de l’espèce ici et en fait première obs tout court – coche √ 🙂
Sterne de Dougall (Roseate Tern): avec 133 Dougall dénombrés, on dépasse déjà d’un tiers l’effectif total de l’an dernier, avec un maximum de 41 oiseaux en 2h de suivi le 17/9. Toujours sympa de voir cette belle espèce, dont le statut de conservation en Europe est plutôt précaire avec des effectifs ne dépassant pas les 1900 couples au début des années 2000, essentiellement aux Açores et en Irlande.
Sternes pierregarin et Sterne arctique (Common & Arctic Terns): 8760 ind., en flot plus ou moins continu depuis le démarrage du suivi. La Sterne arctique était visiblement l’espèce dominante en août et début septembre, mais actuellement la tendance est en train de s’inverser, et la Pierregarin devrait logiquement être la plus commune courant octobre et novembre.
Sterne voyageuse (Lesser Crested Tern): au moins 187, généralement en groupes de 2-3 oiseaux suivant les Sternes caugeks, rarement plus d’une dizaine par heure.
Sterne caugek (Sandwich Tern): Troisième espèce la plus nombreuse, avec 2429 migrateurs pour le moment, dont 2000 passent dans la 2e moitié de septembre.
Sterne royale africaine (African Royal Tern): déjà 897 oiseaux, soit un peu plus du double de l’an dernier. Environ 45% de cet effectif défile pendant la dernière décade d’août, avec des maxima de 136/heure le 25.
Labbe à longue queue (Long-tailed Skua): au moins 478 individus! Le passage débute soudainement le 10/8 – jour d’observation des premiers labbes – avec au moins neuf en 1h30, suivis le lendemain par un bel effectif de 70 oiseaux en 2h40 de suivi et quasiment tous les jours par quelques-uns ou quelques dizaines de migrateurs jusqu’au 22/8. Ensuite rien pendant quatre jours, puis reprise modeste tout à la fin du mois pour culminer le 2/9 avec un effectif impressionant de 217 individus en 1h15 de suivi. Sauf erreur c’est un nouveau record journalier pour le Sénégal, établi en à peine une heure d’observation: combien sont passés en tout ce jour-la? Sans doute plus d’un millier… Cette espèce est bien connue pour ses fluctuations d’effectifs d’année en année: sur les sites de nidification en fonction de l’abondance de nourriture, et visiblement sur les sites d’observation côtiers comme Ngor en fonction des vents pouvant pousser les migrateurs plus près des rivages. En 2017, je n’avais eu que 126 individus; même en prenant en compte l’absence de suivi à la mi-août et pendant plusieurs jours en septembre, il est clair que c’était une “petite” année à Labbes à longue queue, contrairement à 2018.
Labbe parasite (Arctic Skua): 266 individus au compteur, auxquels il convient d’ajouter sans doute une bonne partie des 82 labbes “sp.”; Seuls six Labbes pomarins (Pomarine Skua) pour le moment, avec le premier certain le 30/8.
Labbe de McCormick (South Polar Skua): un oiseau typique passe assez près du bord le 20/9.
Pendant les trois mois qui restent pour cette saison 2018 j’aurai un peu moins de temps que l’an dernier pour suivre ce spectacle de la migration: avis aux amateurs qui souhaiteraient venir en renforts!
Puis il faudrait que je trouve le temps de vous parler de nos sorties récentes au lac Tanma, à la lagune de Yène, et le lac Rose… Mais avant toute chose, demain matin on a prévu une sortie en mer au large de Ngor! Compte-rendu et photos à suivre, si tout va bien.