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 !
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…
Just like last year we’re bringing our readers a summary of the past year, reviewing some of the ornithological highlights and discoveries made in Senegal, and recycling some of the pictures and posts that appeared on this website during the past 12 months.
2018 certainly has been a busy year!
We’ll start with the best of all: the discovery of what appears to be an isolated (?) population of Horus Swifts (Martinet horus), some 3,000 km from the nearest known breeding sites and more than 1,600 km from the nearest observations of the species (in northern Ghana). This is probably one of the least expected range extensions uncovered in West Africa in recent years, and something we’re of course quite excited (and rather proud!) of. We found these birds during an epic 4-day trip up north together with Frédéric Bacuez and visiting birder Filip Verroens from Belgium, in early January. Needless to say, the year started off with a bang! Read up the full story here and on Frédéric’s Ornithondar blog (in French). A few of these neat swifts were seen again in February by Frédéric and Daniel Nussbaumer, then in October by Vieux Ngom and myself when some 50 birds were present, again showing signs of local breeding and confirming that these birds are most likely residents here, and just last week a group of visiting American birders saw about 25 birds at Gamadji Sare.
Just a few days earlier, in fact on the first day of the year, we’d already found another species new to Senegal: a Meadow Pipit (Pipit farlouse) at the Yene-Tode lagoon just south of Dakar. This find was a bit more controversial – but probably more expected than those swifts! – in the sense that the pipit shows a fairly unusual plumage for Meadow Pipit and certain characters fit Red-throated Pipit better. However, the unstreaked rump and especially the diagnostic call, which was heard loud & clear several times at close range (but unfortunately not sound-recorded), safely rule out Red-throated Pipit, several of which were present in the area at the same time. Full story, description and many pictures here.
Continuing on the same theme, this past year saw the addition of two more species to the Senegal list: Brown-backed Honeybird – which had already been reported from Wassadou in 2015 but was not documented – and Turati’s Boubou. The former was found by Gabriel Caucanas and friends first at Dindefelo, then at Wassadou and later in the Niokolo-Koba NP (more info here), the latter by resident Casamance birder Bruno Bargain back in October. Both were more or less to be expected and back in July we’d actually predicted that the boubou would be found in Casamance some time soon, given that it is known to occur just across the border in Guinea-Bissau. We’ll write up more about this species in due course, and I hope to soon visit the Ziguinchor area again and see (and record) this little-known species – stay tuned!
With no less than four new species, 2018 definitely boosted the national list which now stands at a respectable 678 species; more on this in a blog piece we wrote on the topic of the national list, which contains a link to a handy spreadsheet with all species seen in Senegal, with English, French and scientific names.
Of course there were also the usual lot of vagrants, mostly Nearctic waders in the Dakar region and especially at Technopole, pretty much as usual!
- Common Shelduck (Tadorne de Belon): eight in the Djoudj NP on 17/1 were likely the same group as seen in the Diawling just across the border in Mauritania on 30/12, while one at Technopole on 18-19/2/18 confirmed the small influx that occurred during the ‘17/’18 winter: 8th and 9th records!
- Red-footed Booby (Fou à pieds rouges): one was photographed at Iles de la Madeleine on 26/1 but was only identified later on, while at Ngor up to two adults were seen on several occasions in spring (17/5-22/5, and again on 11 and 22/6) and one was seen twice in autumn (13 & 15/11). These are the 2nd to 4th records for this tropical seabird, which was seen for the first time in October 2016 only.
- Cinereous (=Black) Vulture (Vautour moine): an imm. west of Fatick on 30/1 and one (different bird) on 26/2 near Sagata, east of Kebemer. These observations coincide with the first records for The Gambia (Feb. ‘18) and Mauritania (Dec. ‘17). We also reported the first record of the species, which had not yet been published so far – more details on the status of this increasing Palearctic vagrant in this piece.
- American Golden Plover (Pluvier bronzé): one at Technopole on 8 April, followed by two autumn birds, at lac Mbeubeusse on 3/11 and barely a week later a different bird at Pointe Sarene near Nianing on 9-10/11. Read more on this species in Senegal here.
- European Golden Plover (Pluvier doré): one at Île de Saloulou (Basse Casamance) on 3/1.
- Lesser Yellowlegs (Chevalier à pattes jaunes): the 8th record was one at Technopole seen by a visiting birder on 8/2 and relocated on 19/2
- Baird’s Sandpiper (Bécasseau de Baird): the second for Senegal (and first properly documented) was found at Technopole on 25/3 and seen again on 8/4.
- Buff-breasted Sandpiper (Bécasseau rousset): two birds stayed for a remarkably long time at Technopole, being present from 13/1 (at least one) up to 19/2 at least, then again on 25/3 though this was probably a new bird given that regular visits earlier in the month failed to relocate the two long-stayers; these are the 8th and 9th records.
- Red-necked Phalarope: (Phalarope à bec étroit): one at Djoudj on 27/2 is the 6th record at least, though it’s quite possible that the species is a more regular visitor than the handful of confirmed records suggest.
- Franklin’s Gull (Mouette de Franklin): one was seen five times between 20/5 and 20/9 at Technopole; we summarised the status and trends of the species in this post.
As usual there are also several African vagrants to be reported, such as Lesser Jacana (Jacana nain) seen on 31/1 and 17/2 (three birds!) at Médina Afia near Manda, Kolda dept., and at Ross Bethio on 15/7 – there are only a handful of previous records, including just one in the north (more on status of this species in this post by Ornithondar). A Pharaoh (= Desert) Eagle-Owl (Grand-duc ascalaphe) filmed at Richard Toll on 20/1 was the third record. Six Senegal Lapwings were found at Kamobeul (Ziguinchor) on 30/9 – apparently the first record in 38 years! Three other species with uncertain status in Senegal – true vagrants or scarce but regular visitors? – were seen in the Niokolo-Koba area: Mottled Swift in February and June; a Forbes’s Plover in June and an Ayres’s Hawk-Eagle on 6/3 (Martinet marbré, Pluvier de Forbes et Aigle d’Ayres) .
A special mention goes to the Kordofan Lark (Alouette du Kordofan) that was photographed at Richard Toll on 1/3 by a group of lucky Belgian birders; this is the first record in several years, and the first pictures to be made available online for this species, prompting us to discuss ID criteria and status in Senegal of this enigmatic Sahel special, see this blog piece co-authored with Simon Cavaillès – by far the most read article on the blog, with more than 500 views since its publication in April.
Several winter visitors were seen in higher than usual numbers or reached areas further south than their usual wintering grounds, such as Short-eared Owl (Hibou des marais; seen in six locations during January-March including a group wintering at Technopole, following the influx in Nov.-Dec.). Other scarce winter visitors included a Little Gull (Mouette pygmée) at Ngor on 12/1, while a group of five Cream-coloured Coursers (Courvite isabelle) near Maleme Hodar (Kaffrine) on 1/3 were possibly the southernmost record ever. Other examples include a Spectacled Warbler (Fauvette à lunettes) near Kaolack on 3/3, a “Desert” Grey Shrike (now surprisingly lumped again with Great rather than Southern Grey Shrike; Pie-grièche grise) in the Boundou reserve on 15/3, and five House Buntings (Bruant du Sahara) at Richard Toll on 1/3.
As usual, a few birds were spotted outside of their regular range in the country: several Pallid Herons on the Cap-Vert peninsula; an African Hawk-Eagle that gave us a bit of an ID challenge at Popenguine (3/11); a Greyish Eagle-Owl photographed at Trois-Marigots on 10/1 (only a couple of previous records from N Senegal, see story on Ornithondar); a Grey Phalarope on 25/2 at Médina Afia (a rare inland record!); a singing Klaas’s Cuckoo near Dagana on 6/10; a Broad-billed Roller at Bango (Saint-Louis) on 31/8; Grey-rumped Swallow at Technopole (7/7); an early Lesser Whitethroat at lake Tanma on 25/9; a Cricket Warbler near Gueuol (north of Kébémer) on 21/11 (Aigle fascié, Grand-duc du Sahel, Phalarope à bec large, Coucou de Klaas, Rolle violet, Hirondelle à croupion gris, Fauvette babillarde, Prinia à front écailleux). In the Djoudj, a Brown Snake-Eagle was reported on 5/12. Familiar Chat and Green Turaco were reported from the Niokolo-Koba NP for the first time, where further observations of Mali Firefinch were made (Traquet familier, Turaco vert, Amarante du Koulikoro). Several species were found for the first time in Casamance, including Glossy Ibis, Singing Bushlark, Plain Martin, Great Reed Warbler – details will follow shortly on this website (Ibis falcinelle, Alouette chanteuse, Hirondelle paludicole, Rousserolle turdoïde). Away from the better known wintering grounds in the north of the country, an Iberian Chiffchaff (Pouillot ibérique) was singing at Wassadou on 25/2, and the Technopole bird found on 31/12/17 continued its presence until 7/1 at least.
New breeding records include what appears to be the first confirmed breeding for the Dakar region of Little Tern in June at Lac Rose with at least 14 nests; in the same location we found a nest of Plain-backed Pipit, while a Quailfinch at lac Mbeubeusse on 18/11 suggests that the species may be breeding in the niayes region (Sterne naine, Pipit à dos uni, Astrild-caille). Successful breeding of White-backed Night-Herons (Bihoreau à dos blanc) was confirmed in two locations in Casamance and breeding is also likely along the Gambia river at Wassadou where Pel’s Fishing Owl (Chouette-pêcheuse de Pel) must also have bred. Black-winged Stilts (Echasse blanche) bred once again at Technopole where low water levels created decent conditions in April-June. And a nice breeding record was that of a female Standard-winged Nightjar found incubating two eggs at Pointe Sarène on 4/8 (Engoulevent à balanciers).
A few unseasonal visitors were noted, e.g. early Marbled Ducks and a Black-necked Grebe near Djoudj on Oct. 6th, Western Olivaceous and Melodious Warblers as well as a Woodchat Shrike and even two European Bee-eaters in June; an adult Sabine’s Gull at Ngor on 30/7 (first July record it seems?), and summer Yellow-legged Gulls at Lac Rose (Sarcelle marbrée, Grèbe à cou noir, Hypolaïs obscure et polyglotte, Pie-grièche à tête rousse, Guêpier d’Europe, Mouette de Sabine, Goéland leucophée). Up north, a White-throated Bee-eater and a Pygmy Sunbird were photographed in January near Saint-Louis (Guêpier à gorge blanche, Souïmanga pygmée).
We also continued our seabird migration monitoring efforts during 2018, both in spring and in autumn. Spring migration was summarised in two posts (covering April and May) but the autumn totals are yet to be published. Highlights included decent numbers of Long-tailed Skua (500!) and Grey Phalaropes (1,256!) seen in August when fairly strong north-westerlies created ideal conditions to see these highly pelagic migrants from the coast; both species saw new day records for West Africa it seems. Other good ones included at least 19 Barolo/Boyd’s Shearwaters in Aug.-Sept., a Sooty Tern on 17/9 and several Bridled Terns, while Great Shearwaters passed through in modest numbers around mid-November (Puffin de Barolo/Macaronésie, Sterne fuligineuse, Sterne bridée, Puffin majeur). A pelagic trip on October 1st yielded reasonable numbers of Wilson’s Storm-Petrels (Océanite de Wilson), some shearwaters and skuas, but no rarities this time round. A visiting birder was lucky to see a White-faced Storm Petrel on 3/12 at Iles de la Madeleine, while an observation of Band-rumped Storm Petrel was reported far offshore off Saint-Louis on 25/9 (Océanites frégate et de Castro).
On the ring recovery front, we managed to read some 100 colour rings, mainly of Audouin’s and Slender-billed Gulls (41 & 19, resp.) but also several Greater Flamingos from Spain, a Common Ringed Plover from Portugal, and the first mentions of Avocet in our database (two birds from Spain) as well as a French Mediterranean Gull (“RV2L”) which appears to be the first recovery of this species from Senegal (Goélands d’Audouin et railleur, Flamant rose, Grand Gravelot, Avocette, Mouette mélanocéphale). I now have some 420 ring recoveries in my little database: maybe this year I’ll find time to write up some of the key findings.
A few blog posts on birding sites and other topics were published in 2018, namely the following:
- Senegal as a destination for birders, written up by Paul Robinson following his visit to the UK Bird Fair in 2017
- Blog posts on the birds of Dindefelo and Wassadou following visits to these two major birding hotspots in the south-east of the country
- The Casamance Bird Atlas by the association APALIS
- Birding the Niokolo-Koba: guest blog by John Rose and Dimitri Dagone
- The formal protection of Technopole back in October was of course a major event
- A xeno-canto audio guide to the birds of Senegal
- Last but certainly not least, the last blog piece of the year covered the description of a new species of Square-tailed Drongo
We’ve also been pretty active writing up more formal pieces on birds in Senegal, with several articles published in 2018. This post is actually getting a bit too long so I’ll write about these recent publications in a forthcoming article. For now, go out birding!
Finally, thanks to all our readers for their support and encouragement throughout the year, which has seen a further increase in number of page views (almost 25,000) and website visitors. Oh and do let me know if I forgot anything in the above review, which is just an informal overview – nothing official here!
It’s always a pleasure to read good trip reports by birders who visit Senegal. More and more visitors now report their sightings through eBird or Observation.org, but few go through the effort of writing up their notes – despite best intentions, as I can sadly testify to myself.
Too many birds, not enough time, right?
A small Danish team visited Senegal last November, and I happened to meet them while seawatching at the Calao at the start of their visit, together with guide Carlos who expertly showed them a great deal of excellent birds – and then again towards the tail end when we briefly met up in Toubacouta. I recently received their trip report, one of the few good ones that were published on Senegal recently. There are useful sections on travel arrangements, weather, timing, pets, and resources (many thanks for mentioning this site!). And very importantly, a brief review of key places visited during the trip: Dakar, Trois-Marigots & Djoudj, Richard Toll, Kousmar, Wassadou & the Niokolo-Koba National Park, Toubacouta & Delta du Saloum, and finally Popenguine. Information on key species is provided along with some info on accommodation and access, and almost all are illustrated with pictures showing local habitats. Next up are species lists by site, followed by a comprehensive list of bird and mammal species seen.
Pretty much all the “specials” were found, both up North and in the Saloum and Niokolo-Koba areas. Also a few less expected birds, such as a high count of Stone-Curlews at Richard Toll (90! with 12 more at Trois-Marigots), a slightly out-of-range African Hobby at Trois-Marigots, a couple of Temminck’s Stints, Shining-blue Kingfisher at Wassadou (though apparently it’s quite regular there at the moment), and an Aquatic Warbler seen during the boat tour to the Djoudj pelican colony (they’re present of course, but seeing one is rare!). And a good breeding record of Fulvous Babbler – apparently one of the few confirmed in the country – with a bird on the nest at Richard Toll.
Oh and I almost forgot – the report is stuffed with brilliant pictures including many of the country’s iconic birds, such as this pair of perfect Swallow-tailed Bee-eaters seen near Toubacouta, or the stunning Cricket Warbler from Richard Toll further down (all pictures in this post by Morten Heegaard, Stig Jensen & Jon Lehmberg).
And make sure to read through to the very end, where you’ll find an enjoyable bonus section on the raptor roost at Ile de Kousmar near Kaolack. To quote the authors, “Why a lot more birders aren’t visiting this roost is a total mystery to us, and that some are even spending a night in Kaolack without coming here is simply beyond belief”. I, for one, am ashamed to say I have not made it to Kousmar yet: next winter, sans faute.
The report can be downloaded directly from here (PDF, 5 MB), or from the Cloudbirders site, which contains a number of other good trip reports on Senegal, many of which are from tours combined with Gambia. Many are fairly dull species lists, but among the more recent ones this report by Birdquest from February 2017 (Podor, Dindefelo, Wassadou, Saloum etc.) is worth a read for those planning a trip to Senegal even if it fails to provide any useful information on where to find the most wanted birds (and there are a few errors as well, e.g. Mali Firefinch is not restricted to Kedougou in Senegal, and Marbled Teal is very much a regular visitor to Djoudj). I guess that’s one of the differences between commercial tours that rush from one place to another (imagine spending just a single day in Dindefelo?!) and a bunch of passionate friends who are keen to share their explorations. Dieuredieuf, Morten, Stig & Jon!
And since we’re talking trip reports – a really enjoyable report in very much a different style is this recent one from The Gambia: BIRDBLOG GAMBIA 2018. Woodsmoke…dust…many birds!
“The ironically named Singing Cisticola showed well, but sang very, very badly, however Scimitarbill and Grasshopper Buzzard rebalanced the cool scale”
Proof that birding trip reports don’t have to be boring reads – highly recommend it, I had a real good laugh!
Last summer I had the chance to be in the UK for the Birdfair 2017. This is the largest annual market in Europe for birdwatchers. There is some overlap with bird conservation and many Birdlife partners are there, but this is primarily a place for the buying and selling of everything that birdwatchers desire; books, optics, but especially birdwatching holidays, and this is big business! Bird tour companies from many South American and African countries had flown in staff to advertise their holidays.
At the fair, South African birder Micheal Mills launched The Birder’s Guide to Africa, which aims to tell birders what is most distinctive about each country’s list of birds and where to go in Africa to most easily see each of the continent’s species. Whilst I do not agree with everything in some of the book’s West African chapters, it is a good start for a discussion of bird tourism in Senegal – which for many reasons would deserve a more prominent place on the Africa birding map (one of the many down-sides of taking very much of a quantitative, purely list-based approach to defining birding destinations, as is done by Michael Mills, is that many countries do get the recognition they deserve).
What is unique? Should more birders visit Senegal, and if so what should Senegalese bird guides do to encourage them? It should be said that I am talking about a certain type of birdwatching tourism – visiting places to make lists of unusual birds – which is the profitable market in which the Birdfair sells. From this perspective, the spectacles of Djoudj, the Sine Saloum and Kousmar are still important, but not enough if the birding guide cannot also find the country’s more unique species.
So, how visible was Senegal at the Birdfair? The short answer is almost invisible! Let’s avoid the historical and perhaps linguistic reasons why The Gambia features at the UK Birdfair, and look at all of West and North-West Africa. Geopolitics affects tourism and, correctly or not, many of the region’s countries are seen as more difficult places to organise tours. Unfortunately, these days large parts of Mali, Burkina Faso, Niger, and northern Nigeria and Cameroon are off-limits to foreign visitors due to ongoing conflict and security concerns. Currently the two most advertised North-West/West African destinations for bird tours are Morocco and Ghana, as destinations for European, North American and South African birders, who are the three main groups.
Let’s take the African Bird Club country lists, which taxonomically almost follow the IOC World Bird List, and query the list. Which species regularly occur in Senegal, but not in Morocco or Ghana and also do not occur widely elsewhere in Africa? This query give Senegal at least 28 “special” species, which it would be a good investment for bird guides to be able to find. Please add your comments to this linked list, which is accessible for editing. Several more could – and probably should – be added, and it’s good to keep in mind that the national list stands at about 680 species (we hope to publish an updated list some time soon on this blog).
Most of the species on this list are birds of the Sahel and the drier, northern regions of the Sudan savanna. The USGS’ excellent recent resources on West African land use shows the western section of the Sahel bio-climatic region, which extends to northern Ethiopia.
Little Grey (or Sahelian) Woodpecker is a classic example. Its patchy distribution, which does not go further east than western Sudan, includes northern Senegal where most recent West African observations have been made, though WaBDaB, which coordinates bird observations for Burkina Faso, Niger and Chad, has a few records.
For the average bird tour operator, Senegal is the easiest destination and there are places where it is often seen (Les Trois Marigots and near to Richard-Toll), but probably many to be discovered – for instance, it was reported just last week “well south of Louga” by a Swedish group. This and many of the Sahel specials are much more species of the Middle Valley described in Bram’s recent trip, than of the more famous Djoudj/St. Louis area and many are not on the Djoudj list.
Other species in the 23 with similarly narrow ranges include Cricket Warbler (present in southern Western Sahara, but very localised it seems); River Prinia (header picture – cryptic species only present in the Senegal River delta, River Niger and Lake Chad, though probably overlooked elsewhere); Sennar Penduline Tit; Golden Nightjar (most recent records from Western Sahara where confirmed breeding, and from Chad); Quail-Plover (hard to find, but there are apparently a couple of reliable sites); and the commoner Black Scrub Robin, Sahel Paradise Whydah and African Collared Dove.
A second cluster of specials occur in and near the Dindefelo reserve, Senegal’s most recent addition to the country’s Important Bird Areas list. This is the only place outside Mali where the Mali Firefinch is reasonably reliably seen. Other species with strange and small global ranges including Dindefelo are Adamawa Turtle-Dove and Neumann’s Starling. The Kedougou area, and Dindefello in particular, probably has more surprises in store and is likely to yield additional Guinean species that just creep into Senegal.
Finally, the sea off Dakar makes the list. Away from the Cape Verde, the Cape Verde Shearwater is only reliably seen elsewhere in Africa, in season, off Dakar and the Iles de la Madeleine trio of Red-billed Tropicbird, Bridled Tern and the recent arrival Brown Booby are common enough in other tropical waters, but with few reliable places in Africa. The Tropicbirds are pretty much guaranteed at any time of the year, whilst the boobies and especially the terns and shearwaters are only present in certain seasons.
And the message from this? Any Senegalese bird guide who gets to know when and where to find these species should have a profitable business and most of the species are far from the hotspots of Djoudj and the Sine Saloum! And to potential visitors – come over and explore, with or without a local guide: you won’t be disappointed.
(post by Paul, with contributions from BP)
An unexpected sighting of a Short-eared Owl (Hibou des marais) migrating past Ngor this morning prompted me to have a closer look at the status of this bird in Senegal, and to attempt to assemble past records and available information about its distribution. It also so happens (a coincidence?) that there were several more records in recent weeks, including one seen just yesterday in the Saloum delta, and one early November in Senegal’s Far East, at Boundou nature reserve. Today’s post will be a rather short one, without any pictures to share – unfortunately (you do get lots of references instead!). [correction! I managed to take a few pics at the end of December, so I’ve inserted them here]
This morning, towards the end of a very quiet seawatch session, I noticed an unusual bird coming in over the ocean from a north-westerly direction, maybe about a kilometer away from land. It was easily identified as a Short-eared Owl thanks to its distinctive shape and plumage: pale plumage, long wings with pale yellow “hands” and a distinctive black comma on the underwing and dark primary tips, which distinguish it from Marsh Owl. It made slow progress, turning to the south and eventually reaching Ngor island, but proceeded without landing and seemed to continue towards the Almadies area (if I’d been at home, I may have seen it from my balcony!!). Could it perhaps have crossed from the Cape Verde islands, or hopped on a ship somewhere to the north of Dakar, and took off upon seeing the Mamelles in the distance?
In summary, Short-eared Owl is a scarce but seemingly regular (and likely annual) winter visitor to Senegal. Most observations are from the north, at Djoudj and Richard-Toll, with a scattering of records from elsewhere in the country: Dakar, Popenguine, Saloum, Boundou.
The earliest available reference is of course by Morel & Morel (who else?), who report to have seen it “on several occasions” around Richard-Toll, but don’t give much other detail other than that it is mainly seen on “autumn” and “spring” passage, with a mid-winter record in January 1978. The only record away from their study site that they mention is of a specimen collected at Sangalkam in the Dakar region, not far from Lac Rose, on 3/2/76 by Blancou.
In the early nineties, Short-eared Owl was regularly observed in the Djoudj national park, with at least 20 records “between 23 October and 29 March: three singles, 1990-91; 12 records in 1991-92 (max. 6 on 10 Dec 1991); five, 1992-93 (max. 3, Jan 1993). Previously only one record was known from the Djoudj (Dupuy 1971)” Elsewhere in Senegal, Sauvage & Rodwell add a single record of one bird at Palmarin in January 1992, but there’s also one from 27/2/91 at Popenguine which they seemingly were unaware of at the time (O. Benoist on eBird).
As is quite often the case it seems, there follows a gap in published data during the late nineties and first decade of the 21st century, and we need to fast-forward almost 20 (!) years until the next published records, listed below. All are of single birds between early November and late January.
- 22/1/10 two in Djoudj NP (N. Borrow et al., ABC Recent Reports, but see also this post on Ornithondar)
- 23/1/13 at Kousmar, Kaolack (S. Cavaillès), where the species is assumed to be a regular yet very scarce winter visitor.
- 15/1/14 in Djoudj NP (W. Jones on eBird)
- 12 or 13/11/14 at Iles de la Madeleine (P. Ricceri & M. Salvioni, Gambia and Northern Senegal trip report)
- 14/12/14 two at St Louis hydrobase (B. Gleitsmann on eBird)
- 24/1/15 Iles de la Madeleine (J. Rose et al., Malimbus 38, 2016: Observations ornithologiques au Sénégal, also noted the same day by this Spanish group)
- 15/11/15 at the Langue de Barbarie NP, photographed (R. Benjumea on Observado.org; see also ABC Recent Reports, and a short post on Ornithondar in which Frederic nicely summarises the status of Short-eared and Marsh Owls)
So just seven records from 2010-2016… and now for 2017:
- 3/11/17 in the Boundou nature reserve (T. Riviere & E. Tanguy on eBird), one of several recent additions to the reserve’s bird list
- 6/11/17 near Palmarin (J. Hooijmeijer, T. Jager)
- 30/11/17 at Kousmar, Kaolack (M. J. Valencia & C. Clemente on eBird)
- 1/12/17 at Palmarin (T. de Kruif on Observado.org)
- 2/12/17 at Ngor, actively migrating
- 14/12/17 at Guereo, roosting under a bush near the Somone lagoon (J. Buvat on Observado.org)
- 25/12/17 near Gandiol (south of Saint-Louis), roosting in a flood plain of the Guembeul area. See header picture and here.
- 31/12/17 at Technopole, Dakar, bringing this autumn’s total to eight birds
Addenda: several more Short-eared Owls were reported in January-March 2018:
- no less than three birds were seen near Palmarin on 22/1/18 by visiting Swiss birders C. Ruchet and Y. Menétrey,
- on the same day (22/1), one was found dead on the N2 road near the Ndiael Fauna Reserve (Daniel & Alix Mignot)
- one was seen on 24/1 “from our cars ‘in the middle of no-where’ north of Kaolack on the road to Louga, i.e. in the Sahel zone with scattered larger trees, by a Danish group (Hans Meltofte et al.)
- seven (!) were at Technopole on 3/2 (E. & J. Regala Ruiz). In subsequent weeks, at least up to late March, up to six birds were regularly reported here. These are also the first February and March records it seems
- one was at Iles de la Madeleine on 25/2 (E. & J. Regala Ruiz)
- one in Djoudj NP on 27/2 (M. Demeulemeester on Observado.org)
That’s now 14 records of at least 22 birds, and definitely a proper influx.
Surely there are other old (and new) records that are hidden in note books, travel reports, trip lists etc., and that were never reported to the ABC for inclusion in the Recent Reports round-up. And maybe even a few birds seen by local birders, eco-guides and park rangers but that were even less likely to have ever been reported, for lack of a proper bird records database. For instance, it has been mentioned from the Ndiael reserve (between Saint-Louis and Richard-Toll), but I didn’t find any records yet. It also turns out that the species has apparently been seen quite regularly in the Khelcom area in recent years, by Dutch researchers working on Montagu’s Harriers here. A shame though that they never reported or published their sightings.
Regardless, what stands out here is the good run of recent records, particularly this year. A coincidence, a real increase of the species, or better coverage and especially better reporting of data by observers? It’s unlikely that there is a real increase in numbers given its overall rather precarious conservation status in Europe. However, Short-eared Owl is known to have highly fluctuating population trends and tends to be a nomadic species with irruptive movements in certain areas, responding to abundance of rodents in both the breeding and wintering areas, so it certainly looks like it’s been a good year for them. Let’s see if other records resurface, or if more are seen in coming months. [note 31/12: several more birds have been seen since I originally wrote this, and one can definitely talk about a proper influx this autumn!]
What about elsewhere in West Africa?
The species is thought to be a regular winter visitor to Mauritania, where it is “recorded in small numbers on both passages (October/November and March/April)”. Isenmann et al. (2010) also mention that in winter the species is seen in open areas around wetlands and in coastal areas (northwards to the Banc d’Arguin). There are at least 12 records from Cape Verde, in August and October-March, from most islands but also including two records of birds “seen from ships at sea between the islands” (Hazevoet 2014), so these were likely of actively migrating birds, just like mine this morning at Ngor.
Short-eared Owl is thought to be a regular winter visitor along the Niger river in Mali (Lamarche 1980 even considers it “rather common” in the Delta Central) and around lake Chad in Nigeria and Chad. At the same latitude, Niger may also be part of its more or less regular range, as there are at least four known records. It is quite rare in The Gambia where there are a handful of observations, surprisingly perhaps mostly from the Upper River Division. The ABC Recent Reports mention one exception, of a bird disturbed while roosting at Pirang, close to Banjul, on 16 February 2003. Olly Fox kindly supplied two recent records from Kartong Bird Observatory, on the coast right on the border with Casamance: 30/10/15 and 24/11/17, both of singles flushed from dry grass/scrub amongst dune vegetation. At least two others were reported from The Gambia later on, including a bird again at Pirang which according to a local guide had been present in the area “most of the winter” (eBird record). The species was also reported in January or February 2018 from Guinea-Bissau for the first time – details will be added later.
Borrow & Demey show records of vagrants in Guinea and in Liberia, with one record each: a very old one from the Fouta-Djallon (Maclaud 1906, see Morel & Morel 1988, Liste des oiseaux de Guinée), while the observation in Liberia was of a bird “hunting insects every evening 18 November to 10 December 1983 on a road passing through a high grass savanna clearing at Tuzon” (Gatter 1998, Birds of Liberia). There also is one record further south, in Cameroon on 14/1/08, of what was obviously a vagrant, flushed “on a lava flow in the southern foothills of Mt Cameroon” (Riegert et al. 2008. The first record of Short-eared Owl Asio flammeus in SW Cameroon. Malimbus 30).
So let’s see if there will be more records this year – I certainly hope so, as it’s always a pleasure to see this special owl, wherever in its wide range that may be (it is indeed an extremely widespread species, with a more or less continuous breeding range throughout Eurasia, in North America, and even the Caribbean and South America).
Post updated several times with records supplied by Simon Cavaillès, Oliver Fox, Jos Hooijmeijer, Miguel Demeulemeester, Hans Meltofte, Edgar Ruiz and others (many thanks!)
(in case you missed the first part, you may want to read this post first)
Thanks to the important research and conservation efforts targeting Audouin’s Gull, a substantial proportion of the population carry colour-rings, to the extent that in any given group one encounters here in Senegal (and elsewhere of course), there are bound to be some ringed birds, usually up to around 15% of all birds. As far as I know this is far more than for any other species that spends the winter here in Senegal; only Black-tailed Godwit comes close (often 5-10%) and maybe Osprey. For instance at Palmarin last month I managed to read 32 rings out of a total of ca. 400 birds, out of which some 200-250 were either close enough to read rings, or were standing (rather than sitting, in which case rings aren’t visible). That’s roughly 13 to 16% of individuals carrying coded rings!
The first mention that I found of a colour-ring recovery is from Delaporte & Dubois (1990) who on 26/1/88 at Saint-Louis observed a bird ringed as a chick in spring 1981 on the Chafarinas islands. Del Nevo and colleagues also noted that many of the birds they counted were ringed, e.g. on 30/9/92, no less than 24 (14%) of 167 birds were ringed: 18 had a darvic [=plastic ring with alphanumerical code] and six had a metal ring only. In 1994 in Palmarin, a Scandinavian team were able to read 16 colour-ringed birds from Spain (out of at least 456; Bengtsson 1994), while Sauvage & Rodwell mention nine colour-ringed birds originating from Spain, in Saint-Louis. The Dutch 1997 expedition managed to read nine rings, out of the 858 gulls that they counted, noting that “these birds presumably all originated from the Ebro Delta, Spain” (and certainly not from the Canary Islands as stated by Triplet 2014! The species doesn’t even breed there… not sure where this error originated).
The rings (or “bands” for our American friends) are either white with a black inscription (3 or 4 alphanumerical characters), or blue with a white 4 character code, and can often be read with a telescope or a good camera. White rings are used in Spain (starting with letters A, B, C or a number) and Italy (I or K), while blue rings are in use in Portugal (with first character P). French birds have a combination starting with F (since 2013; prior to this Italian rings were used); Moroccan ones with M. The images below show an Italian and two Spanish birds (“BDCT” appears twice, photographed in Aug. 2016 and Sept. 2017).
Origin of wintering birds in Senegal
I now have close to 50 ring “recoveries” related to 44 birds, most of which are from Palmarin (39), the others being from Technopole. Adding other sightings in Senegal of these same birds (mostly by Ngoné Diop), we have a total of 103 recoveries.
Here’s a quick summary of their origin:
- As can be expected, the vast majority are from Spain, particularly from the Ebro delta which accounts for about a third of all birds for which I know the origin (15 out of 44). Six are from Valencia (PN de l’Albufera, Salinas de Torrevieja), three from Tarragona (Salinas de Sant Antoni), three from the tiny Isla de Alboran between Morocco and Spain, and two each from the Balearic islands (Mallorca and Menorca), from Murcia (Parque Regional San Pedro del Pinatar and Isla Grosa), the Laguna de la Mata in Alicante, and the Chafarinas islands.
- Six birds are from Portugal, but I’m still awaiting information for full details of the five most recent birds (all from Palamarin early September); thanks to Ngoné I know that at least four birds (and likely all six) originate from the colony on Ilha da Barreta (the southernmost tip of the country, near Faro).
- Earlier this month I found my first Italian gulls at Palmarin, three adults (ICTD, ILBJ and K7T). I have not yet received details from the ringing scheme, other than that K7T was ringed in 1998 – so far my oldest bird! Ngoné kindly provided me with info for ICTD and ILBJ as these were already known to her, which allowed me to include Cagliari (Sardinia) and Isola del Giglio on the map below; I will add further info here when it becomes available [Olly Fox kindly informed me that K7T was seen at the Kartong Bird Observatory in The Gambia in November 2016; it was born on Isola dei Cavoli off southern Sardinia].
At least one Corsican bird has been found in The Gambia (Recorbet et al. 2011) and Ngoné has recorded a few French birds in Palmarin. One can assume that some Moroccan birds may also winter in Senegal, and maybe Algerian and Tunisian birds as well. Not quite sure where the Eastern Mediterranean populations spend the winter, but I read that at least some remain around their breeding grounds.
Here’s an example of the “life history” of one of our oldest birds¹, 45P from Spain, pictured in the header image of this post. It was ringed as a chick in 1999 on the Chafarinas islands, and was seen in The Gambia during the 2004/05, 2006/07, 2007/08 and 2011/12 winters, then in October 2014, October 2015, and September 2017 it was spotted in Palmarin (plus a few times on its native island, in April-June). Could it be that many Audouin’s Gulls spend the initial 4-5 months of the non-breeding cycle in Senegal, then move to The Gambia for the remaining 2-3 months of the northern winter?
The age composition of our wintering Audouin’s Gulls varies considerably between areas and apparently also through the season. This was first documented by del Nevo et al.: “Adult birds dominated both surveys and proportionately more adults than first year birds were present during September 1992 than in February 1991. Our observations are consistent with the view that adult Audouin’s Gulls tend to arrive in Senegambia before first year birds; the ratios of first year to adult were 0.1:1 in September and 0.54:1 during February.” Delaporte & Dubois reported an overall proportion of 15% of immatures. These ratios have likely changed now, at least in terms of the seasonality now that some immatures can spend their first summer in the region. Ngoné and colleagues reported estimates of 278 adults and 167 immatures (= 37,5%) in Palmarin for the 2013-2015 period. They also found that adults, 3rd and 2nd winter birds arrive earlier than 1st winter birds, a difference which “is probably due to differences in experience among age classes.”
The differences in “immature-to-adult” ratio between Palmarin and Technopole are striking, and I wish I knew what causes this. Immatures are by far outnumbering adults at Technopole, as opposed to the high proportion (70-80%?) of adults further south, particularly in the Saloum delta. Interestingly, this may not have always been the case: Oro & Martinez mention that juveniles winter further south than older 2-3y gulls, in the Senegambia region: “After the breeding season, 2-3y and older gulls were recovered mainly at the E and S Iberian Peninsula coasts. During the winter season these gulls moved southwards, especially to the Atlantic coast of Morocco. Juveniles behaved differently, moving further south than 2-3y and 4y or older gulls, reaching the Senegambia coast in high percentages (81,8%).” Is it possible that this was at a time when a new generation of young birds was in process of establishing an overwintering tradition in Senegal and The Gambia, returning in subsequent winters? That would explain why there are currently more adults than juveniles.
Two ringed individuals show how birds wintering in Senegal will typically spend their first year around the Cap-Vert peninsula, before moving on to the Saloum delta once they are older: BNH5 was ringed as a chick in June 2011 in the Ebro delta, after which it was seen at Technopole in July 2012, but during its third winter in Dec. 2013 (N. Diop), and again in Sept. 2017, it was in the Palmarin lagoons. AWNV, born in 2010 in Mallorca, was first at Technopole while in its second summer (July 2012), while in 2015 and 2016 it was in Palmarin. Some birds already move to Palmarin during their 2nd winter (e.g. BWU9), or even 1st winter (BPZ9, seen by Simon in January 2013, then by Ngoné in December of the same year and in Oct. 2015, and last month I saw it again. Talk about site fidelity!
All ringed birds recovered from Technopole were at most two years old, though of course there are some older birds and every now and then a full adult will show up. BYPB is a typical first-year bird, seen here in March 2017.
Among the ringed birds that I have found there are quite a few old individuals, the oldest being nearly 20 years old. Indeed, Audouin’s Gull is a long-lived species with a high adult survival rate (and relatively low fertility). The oldest bird I have is from Italy, at 19 years, while from Spain there’s 45P and 66P, both born in 1999; Ngoné had already seen both in 2014 and 2015 in Palmarin; 45P and was again at Palmarin earlier this month, while I saw 66P there last year at the end of August last year.
The little chart below shows the distribution by age at the time of the last sighting, for 43 birds for which I have the ringing year (birds are typically ringed as chicks, usually in June, so we know their precise age). One can clearly see the predominance of birds in their first year (= juveniles and 1st winter), though this is hardly surprising given that these all correspond to Technopole recoveries. I don’t know how to explain the near-absence of two- and three-year old birds.
Ngoné’s systematic visits to Palmarin have resulted in some 500 ring readings, which of course allow for a more thorough analysis than my anecdotal observations. Through modeling the team has estimated annual survival rates and the size of the wintering population in Palmarin, which are summarised in this informative poster presented at PAOC just about a year ago. There are of course also a few interesting individual stories in the lot, such as two Spanish birds that were ringed on the 15th and the 19th of June 2015 respectively, and that were seen within a few weeks after they left their colony (25/8/15 and 15/9/15).
To be continued…
Many thanks to Ngoné Diop for her input!
¹ The oldest bird we have is “FDA”, ringed as a chick in June 1988 (!) at Islas Columbretes, Castellon, and seen in 2015 and 2017 in Palmarin, and in Dec. 2017 in The Gambia.