An update on this autumn’s seabird migration at Ngor is long overdue, so here we set off the season’s summary with the month of August. I managed to count migrants during 18 hours spread out over 16 sessions, starting with the first on August 9th, straight after coming back to Dakar from a short break Up North. As usual I tried to do relatively brief sessions (usually about an hour) as often as possible, typically early morning about an hour after sunrise. And always from the Club Calao terrace, of course.
With some 7,100 birds counted, numbers passing through during August were about average in comparison with previous years. The few highlights so far were a Great Shearwater (Puffin majeur) flying SW on the 10th which I believe is the first August record, more than usual ‘Macaronesian’ Shearwaters (=Boyd’s or Barolo, Puffin “de Macaronésie”) with no less than 21 birds spread out fairly evenly throughout the period, and again a decent amount of Long-tailed Skuas (Labbe à longue queue). So far, 226 of these elegant pelagic skuas passed through, compared to 213 in August 2018; last year a record 500 were logged during the entire season. Top day was the 20th when I counted a very honorable 84 birds in just one hour, surprisingly during modest NNW wind – always impressive seeing loose flocks of up to 15-20 birds, usually including several adults. None were seen the following two days but during 24-26th there were 89 in 4h35′. Last year the peak passage was during the first decad of September when no less than 217 were counted in just 75′ on 2.9.18, so it’s possible that quite a few more Long-tails will pass through in coming weeks, though this will in part depend on wind conditions: moderate to strong winds from W to NW are usually required to see this species in double or even triple digits (in 2017, hardly any were seen, as shown in the chart below where the dashed line is 2017 and the dotted line 2018; solid line is hourly average per decad).
Other pelagics included early Sooty Shearwaters (Puffin fuligineux) with seven birds during 24-26 August, and three Sabine’s Gulls (Mouette de Sabine) on the 20th. September and October should see many more of these two species! In contrast with last year when more than a thousand birds were seen in August when conditions were good for this species, just three Red Phalaropes (Phalarope à bec large) were detected this past month, though I had the first small flock this morning Sept. 1st, about 15 towards the SW and one coming in from the N and landing at sea. Of course many must have passed through these past few weeks, just too far off-shore for them to be seen from the coast.
What was most likely the same Red-footed Booby (Fou à pieds rouges) was seen daily from 9th-12th, usually flying past at close range and sometimes feeding just behind the surf, with two birds together on Aug. 17th. I also twice saw one in July so it’s quite possible that at least one of these two immatures – both dark morph, as all others seen so far – oversummered around the peninsula.
As usual, the most frequently seen wader was Whimbrel, with just a handful of Oystercatchers and Bar-tailed Godwits each (Courlis corlieu, Huîtrier pie, Barge rousse). The lower number of waders compared to the past few years is probably due to the late arrival of the rains and a four-day gap in my presence during the last week of the month (waders tend to be seen mostly during and just after spells of rain here).
The table below lists all species with totals for the month, with 2017 and 2018 numbers to compare with. Note that the vast majority of the ‘Comic’ Terns were Arctic, and the higher number of Roseate Terns is possibly explained by the fact that I may feel more confident identifying these birds (Sterne arctique/pierregarin, Sterne de Dougall). Oftentimes, Roseates are migrating 2-3 birds together, usually mixed in with Arctic Terns.
|Cape Verde Shearwater||0||100||1|
|Grey (Red) Phalarope||3||1,123||0|
|Lesser Black-backed Gull||0||0||1|
|Large gull sp. (prob. Kelp Gull)||1||0||2|
|Lesser Crested Tern||4||40||41|
|African Royal Tern||342||585||166|
|Catharacta Skua sp.||0||0||1|
|Number of days||16||22||13|
|Number of hours||18h05′||26h20′||17h05′|
Meanwhile at Technopole, the lagoons are finally starting to fill up again now that we’ve had a few decent showers, though a lot more will be needed to ensure that the site remains wet all through the dry season. There’s a good diversity of waders again and breeding activity is at its peak for many of the local species. Striated Heron for instance is now very visible, and last Sunday I saw a pair feeding a recently fledged young at the base of one of the Avicennia stands on the main lagoon, while Spur-winged Lapwing juveniles are all about, Zitting Cisticolas are busy tending their nest, and this morning a small flock of juvenile Bronze Mannikins was seen (Héron strié, Vanneau éperonné, Cisticole des joncs, Capucin nonnette).
Several wader species are starting to pass through again, such as Common Ringed Plover, Little Stint, Curlew Sandpiper and Marsh Sandpiper (Grand Gravelot, Bécasseau minute, Bécasseau cocorli, Chevalier stagnatile). It’s also peak season for Ruff, with a very modest max. so far of 148 counted this morning (Combattant varié).
On the gulls & terns front, a Mediterranean Gull was still around on 18 & 25.8, probably one of the two immatures that were seen in May-July and apparently completing its summer stay here (these are the first summer records for the species in Senegal), while the first juvenile Audouin’s Gulls of the year were also seen last Sunday, Aug. 25th (Mouette mélanocéphale, Goéland d’Audouin, . This morning a White-winged Tern was of note, as were 24 Little Terns resting with the other terns or feeding above the main lake (Guifette leucoptère, Sterne naine). Three Orange-breasted Waxbills and three Long-tailed Nightjars on 11.08 were far less expected (Bengali zebré, Engoulevent à longue queue).
This morning’s eBird checklist has all the details.
Divers articles consacrés à l’avifaune sénégalaise ont été publiés ces dernières années, nous incitant à faire une petite synthèse de ces publications. Le Sénégal est depuis une cinquantaine d’années une terre fertile pour les études ornithologiques, et ces dernières années cela n’a pas changé. Peut-être bien au contraire, même s’il n’y a plus de vrais ornithologues tels que les Morel ou Baillon résidant au pays – peut-être qu’un jour on se risquera à une note sur les nombreux chercheurs et autres personnages ayant marqué l’histoire ornithologique du pays. Peut-être.
Pour le moment, on se limitera aux 3-4 dernières années (2016-2019), en commençant par les publications ayant trait à l’écologie des espèces, suivi par quelques traités taxonomiques pertinents. La deuxième partie couvrira principalement les articles traitant du statut, de la phénologie et de la répartition d’espèces. J’en oublie certainement, donc tout complément que vous pourrez apporter sera grandement apprécié! Une partie des articles qui suivent sont déjà accessibles en ligne, p.ex. sur le site ResearchGate. Quelques-uns se trouvent sur notre page Ressources. Si nécessaire, je peux aussi fournir la plupart sur demande.
Seul bémol, l’absence quasi totale d’auteurs sénégalais dans les publications qui suivent… espérons que la relève ornitho locale – elle existe bel et bien, timidement – pourra changer cet état des lieux dans un futur proche. Ce triste constat a même été démontré, chiffres à l’appui, dans un article récent paru dans la revue Ostrich: Cresswell W. 2018. The continuing lack of ornithological research capacity in almost all of West Africa. Ostrich 89: 123–129. [Le manque continu de capacité de recherche ornithologique dans presque toute l’Afrique de l’Ouest]
- Comment les Busards cendrés font face au Paradoxe de Moreau pendant l’hiver sahélien: Schlaich et al. 2016. How individual Montagu’s Harriers cope with Moreau’s Paradox during the Sahelian winter. Journal of Animal Ecology (doi: 10.1111/1365-2656.12583).
Cette étude sur le Busard cendré, menée par une équipe franco-hollandaise, illustre de manière concrète comment un hivernant paléarctique répond au paradoxe de Moreau. Ce terme fait référence au phénomène des conditions écologiques se dégradant au fur et à mesure que la saison d’hivernage avance dans le Sahel alors que les migrateurs doivent se préparer pour leur migration prénuptiale bien que les conditions soient alors plus sévères. En suivant 36 busards hivernant au Sénégal, l’équipe a étudié leur utilisation de l’habitat et leur comportement tout en collectant des données sur l’abondance des criquets, leur principale source d’alimentation sur les quartiers d’hiver. Ils ont trouvé que la fin de la période d’hivernage pourrait constituer un goulot d’étranglement au cours du cycle annuel, avec des effets de report possibles sur la saison de reproduction. Les changements climatiques en cours avec moins de précipitations dans le Sahel, associés à une pression humaine accrue sur les habitats naturels et agricoles, entraînant dégradation et désertification, rendront probablement cette période plus exigeante, ce qui pourrait avoir un impact négatif sur les populations d’oiseaux hivernant dans le Sahel.
Le Busard cendré est l’une des rares espèces à être bien étudiée au Sénégal, notamment par des chercheurs de l’Université de Groningen (dont Almut Schlaich et Ben Koks) et du CNRS en France (V. Bretagnolle et cie.). La Barge à queue noire et dans une moindre mesure peut-être le Balbuzard pêcheur, deux autres espèces prioritaires pour la conservation en Europe de l’Ouest, sont également relativement bien suivies dans leurs quartiers d’hiver au Sénégal et régions limitrophes.
- Sélection de l’habitat, “home range” et taille de population de la Marouette de Baillon dans le delta du Sénégal: Seifert, Tegetmeyer & Schmitz-Ornés 2017. Habitat selection, home range and population size of Baillon’s Crake Zapornia pusilla in the Senegal Delta, north-west Senegal. Bird Conservation International (doi:10.1017/S0959270917000077).
Les trois chercheuses (équipe 100% féminine, fait assez rare pour le signaler !) se sont penchées sur une espèce très peu connue et difficile à étudier, en utilisant une approche multi-échelle pour évaluer les exigences en matière d’habitat de la Marouette de Baillon dans le delta du fleuve. Elles ont suivi par télémétrie 17 individus dans le PN des Oiseaux du Djoudj, puis ont modélisé à partir d’images satellitaires et des données de capture la probabilité de présence ainsi que la densité de la population. La taille du domaine vital de l’espèce mesure en moyenne 1,77 ± 0,86 ha, avec des différences significatives entre habitats. La Marouette de Baillon préfère au sein de ses habitats les structures de bord, comme les pistes battues, les bords des plans d’eau ouverts, ainsi que les limites d’une végétation spécifique. Basé sur les modèles de régression, 9’516 ha d’habitat favorable ont été identifiés dans la zone Djoudj, avec une taille de population potentielle de 10’714 ind. (3’146-17’408). Les zones humides du delta du fleuve ont donc une importance exceptionnelle pour les populations africaines et peut-être aussi européennes.
La même étude a également permis la publication, en 2015, d’un article sur le régime alimentaire de ce rallidé : Seiffert, Koschkar & Schmitz-Ornés 2015. Diet of Baillon‘s Crakes Zapornia pusilla: assessing differences in prey availability and consumption during the breeding season in the Senegal River Delta, West Africa. Acta Ornithologica 50: 69–84. [Régime alimentaire de la Marouette de Baillon : évaluation des différences en matière de disponibilité des proies et de consommation pendant la saison de reproduction dans le delta du fleuve Sénégal].
- Ecologie de l’alimentation de phaétons se reproduisant dans deux environnements marins contrastés de l’Atlantique tropical: Diop et al. 2018. Foraging ecology of tropicbirds breeding in two contrasting marine environments in the tropical Atlantic. Marine Ecology Progress Series 607: 221–236.
Menée par Ngone Diop, cette étude combine le suivi par GPS, des variables environnementales et des échantillons des régurgitations au cours de l’incubation et de la ponte pour comprendre l’écologie alimentaire du Phaéton à bec rouge, ainsi que les stratégies de recherche de nourriture susceptibles de changer entre deux environnements marins différents: les Iles de la Madeleine (situées dans la remontée du courant canarien) et l’île de Sainte-Hélène au centre de l’Atlantique sud. Des différences substantielles observées dans le comportement d’alimentation entre les deux colonies indiquent qu’il faut être prudent lorsqu’on extrapole les habitudes de recherche de nourriture des oiseaux de mer tropicaux se reproduisant dans des environnements océanographiques contrastés. La surexploitation de petits poissons et du thon peut réduire les possibilités d’alimentation et conduire à une concurrence avec les pêcheries. On incluera le résumé d’une autre publication par Ngoné, celle-ci sur la taille de la population et la phénologie de reproduction de nos chers phaétons du PNIM, dans la 2e partie.
- Distribution spatiale et comportement de nidification de l’Echasse blanche dans la zone humide urbaine du Technopole: Diallo, Ndiaye & Ndiaye 2019. Spatial distribution and nesting behavior of the Black winged-stilt (Himantopus himantopus himantopus, Linnaeus 1758) in the urban wetland of Dakar Technopole (Senegal, West Africa) – J Biol Chem Sciences 13: 34-48.
Cette étude menée par Yvette Diallo de l’UCAD a été conduite en deux temps, d’abord en 2012 puis en 2017, permettant d’établir les effectifs et de décrire quelques éléments de la biologie de reproduction de l’Echasse blanche. Des dénombrements réguliers pendant la saison de reproduction (délimitée de manière un peu trop restreinte par les auteurs, qui n’ont couvert que la période de mai à août et non d’avril à septembre) ont permis d’établir un effectif maximum de 531 ind. en 2012 et 766 en 2017, les effectifs diminuant dès le début des pluies, lorsque les conditions deviennent moins favorables. En 2012, 25 nids sont identifiés, et pas moins de 79 en 2017. Les résultats sont présentés sous forme de plusieurs graphiques, mais leur interprétation est souvent difficile et on pourra regretter que les conclusions ne sont pas toujours très claires (et que cet article a été publié dans un journal plutôt inhabituel!). L’étude a toutefois le mérite d’améliorer nos connaissances de la biologie de cet élégant limicole en Afrique de l’Ouest, dont les données de reproduction dans la région se limitaient jusqu’à récemment à quelques cas au Sénégal et au Ghana.
Et justement, nous avons entamé la rédaction d’une note sur la reproduction de l’espèce au Sénégal et en Gambie, puisqu’une actualisation de nos connaissances est nécessaire en vue des nouvelles données dont nous disposons. Si tout va bien, rendez-vous en 2020 pour la publication.
- Régime alimentaire et aire de nourrissage des Goélands railleurs nichant dans le delta du Saloum: Veen et al. 2019. Diet and foraging range of Slender-billed Gulls Chroicocephalus genei breeding in the Saloum Delta, Senegal. Ardea 107: 33–46.
Peu d’informations sur l’écologie de la population ouest-africaine de ce goéland sont disponibles pour appuyer les actions de conservation. Les auteurs, dont notre ami Wim Mullié – seul ornitho quasi local impliqué dans l’étude – ont analysé le régime alimentaire sur la base des otolithes de poisson dans les pelotes de rejection et les matières fécales collectées à proximité des nids en fin de période d’incubation, entre 2000 et 2015. Les goélands consommaient principalement des poissons des familles Cichlidae (25-93%), Clupeidae (0-54%) et Mugilidae (0-34%). En 2014, trois goélands ont été suivis par GPS en vue d’étudier les déplacements et les zones d’alimentation. Pendant la journée, ils ont passé 27% de leur temps à couver les œufs, 10% ailleurs dans la colonie et 63% à l’extérieur de la colonie lors de déplacements à la recherche de nourriture, qui pour deux oiseaux avait principalement eu lieu dans des lagons bordés de mangroves, des salins, des criques, des rivières et un complexe de rizières abandonnées. Le troisième a exploré presque exclusivement la côte atlantique près d’un village de pêcheurs en Gambie. Le domaine vital et la zone d’alimentation des trois oiseaux mesuraient 2’400 et 1’800 km², respectivement.
On pourrait encore citer d’autres publications ayant trait à l’écologie et en particulier aux stratégies de migration et d’hivernage d’espèces hivernant dans le pays, mais qui ne concernent pas spécifiquement le Sénégal, comme p.ex. Kentie et al. 2017. Does wintering north or south of the Sahara correlate with timing and breeding performance in black-tailed godwits? Ecology and Evolution 7: 2812–2820. [L’hivernage au nord ou au sud du Sahara est-il en corrélation avec la période et la performance de nidification chez la Barge à queue noire ?], ou encore Grecian et al. 2016. Seabird diversity hotspot linked to ocean productivity in the Canary Current Large Marine Ecosystem. Biol. Lett. 12: 20160024. [Les points chauds à grande diversité d’oiseaux marins sont liés à la productivité océanique dans le Courant des Canaries].
Puis pour terminer cette section, mentionnons encore notre note brève relatant l’observation par mes amis genevois d’un Grébifoulque se nourrissant sur le dos d’un Hippopotame (Zapun et al. 2018. African Finfoot Podica senegalensis feeding on the back of a Hippopotamus. Malimbus 40: 70-71). On y décrit un comportement rarement observé d’un des Grébifoulques présents à Wassadou en février 2018. Nous avons retrouvé deux mentions d’observations similaires sur le fleuve Gambie, ainsi que des données d’Afrique australe et du Congo-Brazzaville (avec le Buffle et le Bongo), mais ce comportement n’avait à notre connaissance jamais encore été documenté sur photo.
Place maintenant à la taxonomie, domaine pointu de l’ornithologie moderne qui grâce aux techniques d’analyse génétique continue de chambouler nos connaissances du domaine – et qu’il importe de ne pas négliger car comme le montre la première étude en particulier, les implications en termes de conservation peuvent être importantes lorsqu’un taxon est élevé au rang d’espèce. A propos, Simon et moi avons résumé les principales changements taxonomiques récents affectant le Sénégal dans cet article publié en début d’année sur ce blog.
- Quand la morphologie ne reflète pas la phylogénie moléculaire : le cas de trois sternes à bec orange: Collinson et al. 2017. When morphology is not reflected by molecular phylogeny: the case of three ‘orange-billed terns’ Thalasseus maximus, Thalasseus bergii and Thalasseus bengalensis (Charadriiformes: Laridae). Biological Journal of the Linnean Society XX: 1–7.
Rédigé par une équipe internationale, cet article établit notamment que la Sterne royale africaine devrait être considérée comme espèce à part entière, et qu’elle est génétiquement plus proche de la Sterne voyageuse que de la Sterne royale américaine. Ayant été élevée au rang d’espèce, il devrait maintenant être plus facile de mettre en place un statut de protection et des mesures de conservation de ce taxon endémique à l’Afrique de l’Ouest, dont les populations sont assez vulnérables puisque concentrées en quelques colonies seulement.
- Révision taxonomique du complexe d’espèces du Drongo de Ludwig avec description d’une nouvelle espèce d’Afrique occidentale: Fuchs et al. Taxonomic revision of the Square-tailed Drongo species complex (Passeriformes: Dicruridae) with description of a new species from western Africa. Zootaxa 4438: 105-127.
Un billet avait déjà été consacré à cette découverte sur ce blog: en effet, les auteurs décrivent une nouvelle espèce de drongo au sein du complexe de Dicrurus ludwigii, en utilisant une combinaison de données biométriques et génétiques. La nouvelle espèce, le Drongo occidental (D. occidentalis) diffère des autres taxons du complexe par un bec significativement plus gros et par une divergence génétique importante (6,7%) du taxon « sœur » D. sharpei. La répartition de la nouvelle espèce couvre les forêts de galerie des côtes de Guinée (et de la Casamance !) jusqu’au fleuve Niger et le Bénoué au Nigéria.
Une autre étude génétique (par les mêmes auteurs pour la plupart) concerne le Drongo brillant: même si des recherches supplémentaires sont requises, ils recommandent la reconnaissance de plusieurs espèces au sein de ce complexe, les drongos brillants du Sahel et des savanes d’Afrique de l’Ouest devenant Dicrurus divaricatus. Fuchs et al. 2018. Habitat-driven diversification, hybridization and cryptic diversity in the Fork-tailed Drongo (Passeriformes: Dicruridae: Dicrurus adsimilis). Zoologica Scripta 2018: 1–19. [Diversification engendrée par l’habitat, hybridation, et diversité cryptique chez le Drongo brillant].
La suite sera pour dans quelques jours !
There’s a handful of bird species here in Dakar that remain rather enigmatic, and whose status and patterns of occurrence remain to be fully understood. One of these is the Yellow-throated Longclaw (Macronyx croceus), a member of the pipits and wagtails. Longclaws are a genus that is entirely restricted to Africa where eight different species are known, some of which have small or patchy distribution ranges. The Yellow-throated Longclaw is certainly the most widespread species, but here in Senegal we’re right at the edge of its range: while nowhere common, it’s probably quite widespread in Basse-Casamance (Ziguinchor, Oussouye, Cap Skirring/Diembering, Kafountine/Abene… even Sedhiou a bit further inland). There are just a handful of observations from north of the Gambia, where the species is apparently on the decline, at least in coastal areas where very few recent sightings it seems. The scant information that we have is mostly based on old records from the Dakar peninsula, more on these later. It’s clear though that this is a very little known species that at best is obviously scarce and localised, and while I certainly have it somewhere in the back of my mind when visiting lac Rose, I didn’t think I’d ever see it here.
Until yesterday morning, when I came across not one but two of these cool “sentinels” as they’re called in French: first one on the margins of the Mbeubeusse wetlands (99% dry now!), a bird flying over a reedbed and landing out of sight quite a distance away. A rather frustrating sighting but just decent enough to confirm the id: broad wings, medium-long tail with white corners, vivid yellow throat and breast with black markings on side of throat. I may have heard it singing shortly before I saw it but not sure as it called only once and Crested Larks can sound a bit similar!
The second bird was found barely an hour later at lac Rose, right at the Bonaba Café on the northern shores of the lake, and “performed” much better than the first! Upon arriving at this site, I could clearly hear it singing for several minutes on end; it even allowed me to get quite close so I could document this bird on camera (and on sound recorder: a sample of its simple yet rather melodious one-note song here.
These are the old records known from the Dakar area:
- August 1968 – “seen several times in coastal region 20 km east of Dakar” (M.P. Doutre; Morel & Morel) – this may well be near lac Malika or Mbeubeusse
- 9 April 1977 – 2 singing, Lac Rose (W. Nezadal on eBird)
- January 1984 – “Dakar” (Paul Géroudet in M&M)
- February 1990 – one seen “north of Dakar” within the Dakar atlas square, but this could be anywhere between Guediawaye and Kayar… (Sauvage & Rodwell 1998)
- 17 February 1991 – 1, Lac Malika (O. Benoist on eBird)
More recently, there’s an observation of no less than five birds on 18 Jan. 2011 at lac Rose seen during a tour organised by Richard Ottvall for the Swedish AviFauna group. Almost five years later, another mention from the same site, unfortunately without any further comments other than that it was on 20 November 2014 at lac Rose (near the southern edge, not far from Le Calao lodge), by J. Nicolau during a scouting visit for Birding Ecotours. The only other recent record north of the Gambia that I came across was of two birds in the Saloum delta (though where precisely?) on 8 January 2017 (J. Wehrmann on observation.org).
Could it be that there are just a few birds that are mostly escaping us – some relictual population from greener days when rains were plentiful here? It’s hard to believe though that if they were present year-round, that we haven’t come across them since we do visit Lac Rose and Mbeubeusse fairly regularly, in all seasons. Or are they present only certain years, and if so at what time of the year? The series of observations from the late sixties up to early nineties is certainly intriguing and would suggest that the species was fairly well established in the Niayes region, especially when one factors in the even lower observer pressure than currently. With records from January (2), February (2), April (1), June (the two in this report), August (1) and November (1) it seems that they can be expected pretty much at any time of the year. More investigations are needed of course and we’ll see if we can find out more in coming months.
Some other good birds from the weekend…
Also on the lake shore were a few Lesser Black-backed Gulls with a second summer Yellow-legged Gull in the mix, some 33 Audouin’s Gulls (i.e. far less than last year at the end of June), Little Terns at colony, a female Greater Painted Snipe (first time I see this species here) and a few other waders (nine Sanderling, 40+ Common Ringed Plovers. a few Greenshanks and Grey Plovers, one Redshank), as well as at least three Brown Babblers – my first in the Dakar region I believe (Goélands brun, leucophée, d’Audouin; Sternes naines, Rhynchée peinte, Sanderling, Grand Gravelot, Chevaliers aboyeur, Pluvier argenté, Gambette, Cratérope brun).
A brief walk and a quick scan of the steppe to the north-east revealed a few Singing Bush Larks and the usual loose flocks of Kittlitz’s Plovers (31 birds including at least 2 small chicks and an older juv.), though no Temminck’s Coursers were seen this time round. Also here was another Osprey and a few Blue-cheeked Bee-eaters, which were also heard around the lake (Alouette chanteuse, Gravelot pâtre, Balbuzard pêcheur, Guêpier de Perse).
At Mbeubeusse, apart from the Longclaw the surprise du jour was a fly-over pair of Spur-winged Geese (Oie-armée de Gambie), no doubt looking for fresh water…
Target of the day however was Black-winged Stilt – well, in addition to a few others such as the gull flock I wanted to check on – as I was keen on gathering more breeding data. More on this in a later post, but here’s already a picture of an adult with one of its chicks, from Mbeubeusse where there’s hardly any water left in the small pond close to the main road (= near the end of the Extension VDN). Just like last year, several families and nests were found at Lac Rose, and this morning at Technopole I managed to do a fairly extensive count of the number of families and nests. The breeding season is still in full swing and I hope that many of the birds that are still incubating will see their eggs hatch: with low water levels, predation by feral dogs, Pied Crows, Sacred Ibises etc. may be even more of a risk than usual. Overall it certainly seems that there are fewer nests and fewer grown chicks than last year – again, more on this later!
Not a target but always a pleasure to watch these highly underrated doves:
Other stuff of interest from this morning’s visit to Technopole – shortly after the first rain of the season (a very small shower only, but nevertheless: first rain since early October!) – were four Broad-billed Rollers which just like last year seem to favour the area to the NW of the main lake, again Diederik Cuckoo singing, the same Yellow-legged Gull as the previous day at Lac Rose, close to 1,500 Slender-billed Gulls including the first juveniles of the year, as well as the first Black-tailed Godwits of the “autumn”: these are birds that have just arrived back from western Europe, most likely failed breeders. (Rolle violet, Coucou didric, Goélands leucophée et railleur, Barge à queue noire)
Full list here.
Visitors to Technopole should know that there is now a poste de contrôle (check point) near the entrance, just after the Sonatel building, manned by rangers from the DPN (National Park Service). This is the first tangible sign that the newly acquired protected status of the site is actually making a difference; hopefully their presence will help prevent illegal dumping and may give potential visitors more of a sense of security. Please do stop and explain that you’re there to watch birds (they will ask anyway, and if you don’t stop they’ll tell you off on the way out). Do note that entrance remains free to all, and that there’s no entrance fee.
It’s been a while since Technopole last featured here, mostly for a lack of birds… With water levels now extremely low – the main pond only has a few shallow patches of water left – and as a result bird numbers are very low. Just a few hundred Black-winged Stilts, and Spur-winged Lapwings, 100-200 Slender-billed Gulls, the odd Audouin’s and a few oversummering Black-headed Gulls, a few lone waders here and there, 6-8 Greater Flamingos and that’s about it. Luckily there’s always something to see at Technopole, and even if overall numbers of migrants are low at the moment, there’s always some of the local species for which it’s now breeding season!
But more about the gulls first.
One of the previous winter’s Mediterranean Gulls remained up to 10 June at least but only allowed for a few poor records shots, rather unusually a 2nd summer (rather than 1st summer) bird. Apparently the first June record for Senegal, of what in the past 10-20 years has become a regular winter visitor in small numbers to the Dakar region. The last Yellow-legged Gull (Goéland leucophée) was seen on 2 May, also a rather late date.
Actually I just realised that I hadn’t shared some of the better pictures of the star bird of the spring here: the 2nd c.y. Laughing Gull, which ended up staying from 25 April until 22 May at least. With the exception of the adult bird this spring (which was seen only twice by two lucky Iberian observers 🙂 on 21-23 April), all previous records were one-day-wonders.
And while we’re at it, here’s the stunning adult Franklin’s Gull in breeding plumage, which unfortunately didn’t linger and was seen just once, on 30 April, at fairly long range hence the hazy pictures:
This bird is from the following day, probably the 2nd summer seen several times between 13 April and 2 May:
Several Black-winged Stilts are still on the nest, but breeding success appears to be low (because water levels are too low, making the nests more vulnerable?). Only a handful of little stiltlets are seen on each visit, and hardly any older juvs. are around. Wondering whether those at Lac Rose may be more successful this year…
Greater Painted-Snipe (Rhynchée peinte) may also be breeding as a pair was seen on 23 June and a male two weeks earlier in the same area (past golf club house on edge of lake near the small baobab!).
And this year there are quite a few Little Bitterns around, quite obviously more than in previous years, with sightings including several singing birds and pairs in at least five locations. I guess the number of territories all over the Grande Niaye de Pikine could easily exceed 10-12 pairs/singing males. Here’s a rather poor picture of a pair seen on our most recent visit, just before it flew off:
Little Grebe (Grèbe castagneux) was once again confirmed to be breeding, though later than in previous years: an adult with a still downy juv. (aged 1-2 weeks?) was on the small pond past the golf course on 10 June, in the same site as in previous years. Previous records in central and northern Senegal were during Dec. – April (read up more about the breeding status of Little Grebe in Senegal & Gambia in this paper that we published in Malimbus last year)
Another nice surprise last Sunday (23/6) was the first Diederik Cuckoo (Coucou didric) of the season in these parts of the country: a singing bird flew high over the pond coming from the Pikine side, then was heard again later on in the tree belt near the football field. Almost as good as hearing the first Common Cuckoo in early April, back “home” in Geneva!
We’re almost there! In the end, there’s been quite a lot to catch up on since early May…
This colour-ringed Gull-billed Tern which I think I’ve mentioned before is indeed from the small colony of Neufelderkoog in northern Germany – the only site where the species breeds north of the Mediterranean region – and as it turns out it’s only the second-ever resighting of one of their birds in Africa. The first was that of a first-winter bird seen in February 2017 in Conakry, Guinea. Our bird ended up staying at least 16 days, from 13 – 28 April. It was ringed on 18 July 2017 by Markus Risch (“WRYY”: white-red/yellow-yellow) and was a late or replacement brood, and the bird was among the latest fledglings of all.
This Common Ringed Plover was around for some time in April / early May, ringed in Norway (details yet to be submitted).
Also on the ringing front, we’re still waiting to hear back for some of the 40-50 Sandwich Tern ring readings Miguel and I managed to make this spring. One of the most recent birds, seen on May 1st, was ringed in June 2017 at Hodbarrow RSPB reserve in Cumbria (UK), and was already spotted on 25/11/17 at Kartong in Gambia (4,720 km, 148 days). While 2nd c.y. birds all stay in Africa during their first summer, third calendar-years such as this one may already migrate back to Europe.
Rounding off the overview with the most recent addition to the Technopole list: African Wattled Lapwing (Vanneau du Sénégal), which surprisingly had not been seen so far, at least not as far as I know – seems like the species actively avoids dense urban areas, since they are regular just outside Dakar but obviously a bit of a vagrant here in town. One was seen flying past, calling a few times, on 10 June.
Species number 239!
Let’s see if we can manage to find 240 in the next few weeks.
Another visitor from North America showed up recently at Technopole: a superb adult Laughing Gull (Mouette atricille) was found by Miguel Lecoq and Ignacio Morales over the Easter weekend. First seen on 21.4, it was still present two days later when it was also heard calling. Amazingly, later that same week (25.4), Miguel found an immature (2nd year) in the same place!
Identification is pretty straightforward, the main field characters being nicely visible here: dark grey mantle, almost entirely black outer primaries, narrow white trailing edge to secondaries and tertials, back hood with white “eye lashes”, fairly long dark crimson red bill, and rather long dark red to blackish legs. The young bird is also very distinct and is relatively easy to pick out amongst the numerous other gulls that are present at Technopole at the moment: Slender-billed Gulls mostly, but also Grey-headed Gulls (the immatures of which superficially resemble Laughing Gull), and still some Black-headed, Audouin’s and Lesser Black-backed Gulls (Goeland railler, Mouettes à tête grise et rieuse, Goelands d’Audouin et brun).
Proper rare bird record shot:
This is the fourth American species to be seen in Senegal in less than two weeks, once again highlighting the potential of the country to find vagrant gulls and waders: the overwintering Lesser Yellowlegs (Chevalier à pattes jaunes) was last seen on 8.4, followed by a 2nd year Franklin’s Gull (Mouette de Franklin) on 13.4, the American Golden Plover (Pluvier bronzé) from Palmarin (15.4), and now Larus atricilla. And this is by just a small handful of active observers… just imagine what else there is to be found, if only there were more birders here.
There are just five previous records of Laughing Gull:
- An adult in the Saloum delta on 18.3.85 (Dupuy, A.R. (1985) Sur la présence au Sénégal de Larus atricilla. Alauda 53. Two years earlier, a possible sighting in the same place of a bird apparently paired with Grey-headed Gull, could not be confirmed and should thus be ignored.
- An adult at Guembeul (near Saint-Louis) on 12.1.95 (Yésou P., Triplet P. (1995) La mouette atricille Larus atricilla au Sénégal. Alauda 63)
- A 2nd winter in the Saloum delta on 28.12.05, see picture below (A. Flitti; Recent Reports, Bull. Afr. Bird Club 13)
- One flying past the Ngor seawatch site on 7.10.08 (P. Crouzier, P. J. Dubois, J.-Y. Fremont, E. Rousseau, A. Verneau; Recent Reports, Bull. Afr. Bird Club 16)
- An adult at Saint Louis on 10.1.14; a 2nd winter possibly also present (M. Beevers; Recent Reports, Bull. Afr. Bird Club 21)
Elsewhere on the continent, there are records from Morocco, Mauritania, The Gambia, Guinea-Bissau (first records is yet to be published), and possibly elsewhere – most recently, an imm. photographed at the Bijol Islands in Gambia in December 2018. It’s an annual vagrant to western Europe, even in unexpected locations such as on this lake in the Swiss Alps where an adult overwintered in 2005/2006:
Unlike Franklin’s Gull, which has been recorded in all months except for November, with most records in May, July and August, Laughing Gull is obviously a species that is more to be expected in winter, with all records so far occurring between October and April.
Other good birds found during Miguel’s frequent visits these past few days include two other additions to the Technopole list: Golden Oriole on 25.4 (Loriot d’Europe), and Pallid Swift on 23.4 (Martinet pâle). A late Mediterranean Gull (Mouette mélanocéphale) was also a good record, as was the count of 606 Sanderlings.
The site list now stands at 237 species. Which one will be next?
I wrote the preceding paragraphs yesterday, and since then I’ve been – at long last – back to Technopole, as I was up north last weekend and travelling abroad for work this past week. Well, we got the answer: species number 238 is Plain Martin (also known as Brown-throated Martin; Hirondelle paludicole). We had a single bird feeding over the water – often at close range – along with a couple of Barn Swallows (Hirondelle rustique) and several Little Swifts (Martinet des maisons), nicely showing its features. This is a rarely reported species from Senegal, and as it turns out the first eBird observation for the country! It’s rather patchily distributed throughout West Africa, being more common in Morocco, East Africa, and Southern Africa. Considered a non-breeding visitor to Senegal and Gambia, I could only find six old records from Senegal: Morel & Morel list four, followed by one in Jan. 1992 in the Djoudj and one from Mekhe in August 1992. Last year, Bruno Bargain found several at Kambounda (Sédhiou, Casamance), on 2.12.18, but other than those there do not seem to be any recent observations. Very nice sighting and an unexpected addition to my Senegal list – and a cool lifer for Miguel!
Alas no Laughing Gull this morning, but we did see the Frankin’s Gull again. Also another Pallid Swift, as well as new sightings of a colour-ringed German Gull-billed Tern (Sterne hansel) and a Norwegian Common Ringed Plover (Grand Gravelot), plus now two different Med’ Gulls. Let’s try again on Wednesday morning, who knows maybe the gull will be back. It may actually have been around for a few weeks now, as there was a possible sighting at Technopole on March 30th. It’s quite possible that the adult is hanging out by the harbour or elsewhere in the baie de Hann or even Rufisque, and will show up again at Technopole.
April is Tern month!
From mid-March into May, lots of terns pass through Dakar on their way back home from the wintering grounds further south – some as far as South Africa! – and the first half of April is definitely peak time for many species. When conditions are right, literally thousands of these elegant birds may pass through on a single day, and sites such as Technopole can hold several hundreds of birds at any one time. So much that in the past week, I’ve had the chance to see 12 out of the 14 tern species that are known to occur in Senegal, the only ones missing being Bridled and the rare Sooty Tern.
On Monday 8.4 at Technopole, decent numbers of terns were about, mainly Sandwich Tern (+300, likely quite a bit more) with a supporting cast of the usual Caspian and Gull-billed Terns (the former with several recently emancipated juveniles, likely from the Saloum or Casamance colonies), but also several dozen African Royal Tern, a few Common Terns, at least two Lesser Crested, and as a bonus two fine adult Roseate Terns roosting among their cousins. And as I scanned one of the flocks one last time before returning back home, an adult Whiskered Tern in breeding plumage, already spotted the previous day by Miguel. I managed to read four ringed Sandwich Terns but far more were wearing rings, but were impossible to read.
Yesterday 13.4, we went back to our favourite urban hotspot mainly in order to see if we could read some more of these rings. The main roost is close to the northern shore of the main lagoon, quite close to golf club house, which makes it possible to get close enough to the birds to read most rings. We saw most of the same tern species (except Roseate), with the addition of a fine moulting White-winged Tern and a small flock of Little Terns migrating over our heads. The first colour-ringed bird we saw was actually a Gull-billed Tern, but not the usual Spanish bird (“U83”) ringed in 2009 and seen several times herein the past three winters. This bird was even more interesting, as it was ringed in the only remaining colony in northern Europe, more precisely in the German Wadden Sea. Awaiting details from the ringers, but it’s quite likely that there are very few (if any!) recoveries of these northern birds this far south. It may well be the same bird as one that we saw back in November 2018 at lac Mbeubeusse, though we didn’t manage to properly establish the ring combination at the time.
So, back to our ring readings: all in all, we managed to decipher an impressive 14 Sandwich Tern rings – blue, white, yellow & red! – of birds originating from no less than four countries: Ireland, UK, Netherlands, and one from Italy (to be confirmed). Most of these are chicks that were born in summer 2016 and that logically spent their first two years in the Southern Hemisphere, and are now returning back to their breeding grounds for the first time. In addition, a Black-headed Gull with a blue ring proved to be a French bird ringed as a chick in a colony in the Forez region (west of Lyon) in 2018, while a Spanish Audouin’s Gull was a bird not previously read here. I’ll try to find some time to write up more on our ring recoveries, now that my little database has just over 500 entries!
Others local highlights from these past few days are the Lesser Yellowlegs still at Technopole on 8.4 (but not seen yesterday… maybe it has finally moved on), also a superb breeding plumaged Bar-tailed Godwit, still a few Avocets, plenty of Ruff, Little Stint, Sanderling, Curlew Sandpiper and Dunlin, many of which in full breeding attire. And on 13.4, once again a Franklin’s Gull, but also a rather late Mediterranean Gull and what was probably the regular adult Yellow-legged Gull seen several times since December. Three Spotted Redshanks were also noteworthy as this is not a regular species at Technopole. The Black-winged Stilts are breeding again, and the first two chicks – just a couple of days old – were seen yesterday, with at least two more birds on nests; a family of Moorhen was also a good breeding record.
Full eBird checklist from 13.4 here.
Earlier this week at the Calao was just about as good in terms of tern diversity: again the usual Sandwich Terns which are passing through en masse at the moment, with some LCT’s in the mix, several dozen Common Terns and the odd Roseate Tern hurriedly yet graciously flying past the seawatch spot, and of course more Royal Terns en route to Langue de Barbarie or Mauritanian breeding sites, a lone Caspian Tern, and this time round an even less expected White-winged Tern (and just two Black Terns). Oh and also the first Arctic Tern of the season! The first birds in spring are typically seen at the end of March or first half of April; earliest dates (2015-2018) are 16.3.18 and 25.3.16. The numbers of migrating terns were really impressive here on Saturday 6.4: a rough estimate puts the number of Sandwich and Common Terns passing through at 500 and 1200, respectively, in just two hours.
At Ngor, regular morning sessions have yielded the usual Pomarine and Arctic Skuas, Northern Gannets, as well as a handful of Cape Verde Shearwaters feeding offshore on most days. Sooty Shearwaters passed through in good numbers on 6.4, while last Friday (12.4) was best for Sabine’s Gull: 73 birds in just one hour, so far my best spring count. Also several Long-tailed Skuas and the other day a South Polar or (more likely) a Great Skua was present, a rare spring sighting. All checklists for the recent Calao counts can be found on this eBird page.
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.