Archive | Satus & Distribution RSS for this section

La migration en mer devant Dakar: l’automne 2017 (1ère partie)

Voici donc une première ébauche de synthèse de la saison de seawatch 2017, que j’espère pouvoir retravailler par la suite pour une petite publication. En effet, c’est à notre connaissance la toute première fois qu’un suivi aussi exhaustif est fait sur l’ensemble d’une saison. Les efforts précédents ont presque toujours porté sur une période courte (1 à 3 semaines), généralement en octobre. Il y avait donc pas mal de spéculation quant à la phénologie et l’abondance de certaines espèces qu’on supposait passer plus tôt ou plus tard en saison.

Comme le note Niklas Holmström sur son site Senegal seawatching (qui bien qu’il date un peu, contient toujours une multitude d’infos pratiques): “septembre, fin novembre et décembre restent inexplorés et sont des périodes intéressantes pour les pionniers du seawatching ayant envie de faire des découvertes. Les possibilités d’apprendre et de découvrir de nouvelles choses sur ce mystérieux groupe d’oiseaux sont encore énormes, surtout en ce qui concerne l’identification, la mue et les migrations!”. On trouvera notamment une liste des oiseaux de mer vus depuis Ngor ou au large depuis des bateaux, ainsi qu’une synthèse des effectifs notés par les diverses équipes ayant fait des suivis dans les années ’90 et 2000.

J’avais déjà fait un premier point sur la saison 2017 ici, et une note sur notre sortie en mer est consultable ici. Et pour une petite synthèse du passage prénuptial, se rendre ici.

Scopoli's Shearwater / Puffin de Scopoli

Scopoli’s Shearwater / Puffin de Scopoli, Ngor, Nov. 2017

Ces derniers mois, j’ai donc élu domicile sur la terasse du Calao, ayant fait 92 séances (82 dates différentes) entre le 22 juillet et le 5 décembre, pour un total de 125 heures de suivi (et j’ai dépensé une petite fortune en espressos, à 1’500 CFA la tasse, et même pas reçu de rabais!!) Soit une présence sur près de deux jours sur trois pendant la période; quelques séances ont été assurées par Miguel Lecoq lorsque j’étais absent et d’autres ont été faites en sa compagnie – un grand merci à lui! Sans exception, toutes les observations ont été effectuées depuis le Calao de Ngor, généralement le matin entre 7h30 et 9h30 à l’exception de quelques séances plus longues ou en fin de journée. Au final, ce sont un peu plus de 69’000 oiseaux qui ont été comptés.

Les principaux “trous” dans le suivi étaient fin juillet/début août, la 3ème semaine d’août, du 7 au 17 septembre, et les cinq premiers jours de novembre. On a donc fourni un gros effort pour avoir un suivi aussi complet que possible, mais le faire tout seul (ou presque) est bien sûr impossible. Du coup je suis allé observer un peu moins dans d’autres coins ces derniers mois (Technopole, mais aussi Pointe des Almadies, Ngor, Mamelles, Iles de la Madeleine…), mais surtout, j’ai encore plus souvent que d’habitude été absent de la maison, surtout le matin… j’en profite donc pour m’excuser auprès de ma petite famille, et à remercier Madame pour son niveau de tolérance élevé!

On a essayé de compter toutes les espèces de manière systématique, plus particulièrement les puffins, océanites, sulidés, limicoles. labbes, laridés et sternes. A quelques occasions des estimations ont dû être faites pour les sternes, car certains jours lors de passages soutenus c’était impossible de compter tous les oiseaux tout seul. Idem lorsqu’on se trouve devant un flux de plusieurs milliers de puffins. Pour les sternes en particulier, il est parfois difficile de distinguer entre oiseaux en migration active et individus stationnant ou se nourrissant dans la zone; il en est de même pour les Goélands bruns et d’Audouin, surtout en fin de saison.

Essai de synthèse…

Par où commencer? Peut-être par les faits les plus marquants, et notamment les passages impressionnants de Mouette de Sabine, Puffin cendré/de Scopoli, et Puffin majeur avec apparemment des records battus pour chacune de ces espèces. Pas de grandes raretés vues, mais tout de même quelques migrateurs peu courants sont notés, comme le Puffin des Baléares ou le Puffin de Boyd. L’absence ou la quasi-absence de quelques oiseaux de mer comme le Pétrel de Bulwer et les océanites est aussi à relever; ces espèces seraient plus faciles à détecter depuis l’ile de Ngor car on se trouve d’une part sur un point de vue plus élevé, d’autre part plus proche des migrateurs que le Calao.

Aussi 2-3 espèces inattendues, avec notamment un Hibou des marais qui arrive depuis le large, le 2/12, ainsi que deux observations de Huppe fasciée et une de Tourterelle des bois en migration active.

Le tableau ci-dessous est une tentative de résumé du passage des principales espèces: vous y trouverez le total compte, le “taux de présence” (rien de scientifique ici! juste le % de jours de présence de chaque espèce), les premières et dernières dates, ainsi que la date et l’effectif maximal, sous forme de nombre d’oiseaux par heure. En effet, vu que je n’ai pas pu faire un suivi exhaustif avec une présence continue chaque jour (j’aurais dû prendre quatre mois de congés, et encore!), il a fallu trouver un moyen de standardiser afin de pouvoir comparer l’intensité du passage au cours de la saison. J’ai donc calculé pour chaque jour le nombre d’oiseaux passant par heure, puis pour faire les graphiques de présence c’est la moyenne des effectifs par heure que j’ai utilisée. Pas sûr si ça tient la route tout ça, à creuser encore… d’ailleurs s’il y en a qui ont des idées pour analyser les données de manière à les rendre pertinentes, je suis preneur…

Seawatch_2017_Summary

Maintenant pour une brève discussion pour chaque espèce:

Puffins (Shearwaters)

  • Puffin cendré & de Scopoli (Cory’s/Scopoli’s Shearwater): ces deux taxons sont très difficiles à distinguer donc ils sont regroupés ici; avant c’était d’ailleurs bien plus simple car ils étaient traités comme des sous-espèces et non des espèces à part entière. On ne sait pas trop dans quelle proportion chacune des deux espèces est présente, mais c’est sûr qu’il y avait aussi bien de Scopolis que des cendrés. Je soupçonne toutefois que les Scopolis sont largement majoritaires, selon nos observations de l’an dernier et aussi lors du pélagique de mi-novembre. Idem d’ailleurs fin octobre devant les côtes marocaines, avec moins de 10% de cendrés sur les 500 Calonectris vus par l’équipe de Limosa. Voir aussi cette discussion sur l’identification de ces puffins ici. Vus lors de chaque séance à partir du 23 octobre, initialement en petit nombre (1-14 ex., 23-28/10), puis dès le 30/10 le passage s’intensifié: près de 100 ind. par heure le 30, pour culminer du 6 au 11/11. Pendant ces six jours, le flux de puffins est quasi continu, avec presque tous les jours plus de 1,000 oiseaux par heure (max. 4157/h. le 6/11, soit 70 individus par minute). Il est probable que ce passage très concentré ait commencé quelques jours plus tôt, mais il n’y a pas eu d’observations du 1er au 5/11. Après le 11/11 le passage devient moins constant, peut-être en raison du changement de la direction dominante des vents (NE au lieu de N/NW) bien qu’il concerne toujours quelques centaines d’oiseaux par heure du 14 au 16 et le 19/11. Les 3-4/12 il y a de nouveau pas mal d’oiseaux qui défilent – passage qui peut d’ailleurs durer jusqu’à fin décembre, du moins certaines années. En tout, plus de 32,000 individus sont comptés, soit près de la moitié (47%) de l’effectif total toutes espèces confondues.

Corys-ScopolisShearwater_2017_chart

  • Puffin du Cap-Vert (Cape Verde Shearwater): vu à quelques reprises seulement, bien qu’il soit possible que quelques individus soient passés inaperçus dans les gros mouvements de l’espèce précédente. Les quelques oiseaux vus n’étaient pas forcément en migration active, comme p.ex. ce groupe de 11 individus qui se nourrissent devant Ngor le 11/10. Deux puffins vus fin juillet et quatre début août étaient peut-être bien des Cap-Vert, mais trop lointains pour en être certain… Cette espèce doit d’ailleurs être bien plus nombreuse au large, comme en témoignent nos observations du 15/11 lors de notre sortie en mer. La présence de l’espèce devant Dakar semble d’ailleurs hautement variable d’une année à une autre.
  • Puffin majeur (Great Shearwater): l’une des grosses surprises de la saison fut le passage tout à fait inattendu de centaines d’individus début décembre… alors que seul un individu avait été vu début novembre. Fait étonnant, ce passage a eu lieu quasi uniquement le soir: le dimanche 3/12, je note 157 Puffins cendrés/de Scopoli en deux heures de suivi le matin, et en retournant en fin d’après-midi – espérant voir un peu plus de labbes – c’est un flot continu de puffins qui se présente devant moi, avec plus de 700 individus notés en 40′, dont env. 200 Puffins majeurs! Le lendemain pareil: très peu de puffins le matin (juste 14 de type cendré et un fuligineux), mais le soir il y a une bonne centaine de majeurs qui passent vers le sud-ouest, avec un passage soutenu qui dure jusqu’au crépuscule au moins. Vraiment étonnant et tout à fait exceptionnel! Comme quoi, ça vaut la peine de ne pas seulement faire du seawatch le matin – quelque chose qu’on savait déjà pour les labbes, mais pour ces Puffins majeurs ce passage uniquement “vespéral” était vraiment inattendu. Logiquement il s’agirait d’oiseaux immatures à cette époque, car les adultes devraient maintenant avoir regagné les sites de nidification de l’Atlantique Sud. Dommage que je n’aurai pas pu continuer le suivi après le 5/12, car c’est bien possible que ce passage ait continué encore dans les jours suivants.
  • Puffin fuligineux (Sooty Shearwater): l’une des espèces les plus régulières, vue sept jours sur dix et quasiment lors de toutes les séances à partir du 18/9. Le graphique ci-dessous résume la phénologie, sous forme de nombre moyen d’oiseaux par heure, pour chaque décade entre fin juillet et début décembre; il y aurait donc deux pics de passage, mais j’ai mis le pic de la 2ème décade de septembre en bleu clair car il n’y a eu que deux jours d’observation lors de cette période, donc moyenne à prendre avec des pincettes. Comme pour pas mal d’autres taxons, le passage est généralement plus intense par vents d’ouest à nord. Avec 3,600 individus comptés, Ardenna griseus fait partie du Top 10 des espèces les plus nombreuses de la saison.

SootyShearwater_2017_chart

  • Puffin des Anglais (Manx Shearwater): régulier avec des effectifs très modestes de mi-septembre à fin octobre, puis arret quasi total de la migration par la suite, avec juste une observation en novembre puis un seul oiseau le 3/12. Comme je n’ai pas pu faire de suivi entre le 7 et le 17/9, il est bien possible que les premiers oiseaux passent déjà début septembre. Et que pas mal d’individus passent plus au large et ne sont pas détectés depuis le Calao (par contre, ce qui est sympa chez cet oiseau c’est qu’il passe régulièrement près du rivage, contrairement à la plupart des autres puffins).
  • Puffin des Baléares (Balearic Shearwater):  un individu notê le 23/9. Peut-être plus courant que cette seule donnée ne le suggère, mais pas forcément facile à identifier donc peut-être qu’il y en avait quelques-uns parmi la soixantaine de puffins non identifiés que j’ai notés…
  • Puffin de Boyd (ou est-ce de Macaronésie? difficile de savoir quel traitement taxonomique lui réserver; Boyd’s Shearwater): un le 18/9.

Océanites (Storm Petrels)

  • Océanite de Wilson (Wilson’s Storm Petrel): Curieusement, lors de ma toute première séance, le 22/7 (ca parait bien loin maintenant!), je constate la présence d’une cinquantaine d’océanites devant le Calao, en train de se nourrir en faisant leurs va-et-vient papillonnants typiques de l’espèce. Deux jours plus tard, alors que le vent s’est couché, il n’y en a plus que trois. Il faut ensuite attendre le 8/10 pour voir quatre de ces oiseaux, par mer ultra calme de surcroît, puis trois le 11/10 et pas moins de 80 (environ!) le 14/10 et quelques-uns encore les deux jours suivants. Encore un oiseau le 24/10, puis c’est tout!
  • Océanite tempête (European Storm Petrel): un seul oiseau identifié, le 11/11 par mer très calme et un vent du nord bien faible.

Sulidés (Boobies & Gannets)

  • Fou de Bassan (Northern Gannet): un premier individu est vu le 18/9, mais ensuite il faut attendre un bon mois avant le suivant, puis ce n’est qu’a partir de début novembre que l’espèce devient régulière. Sur les 65 individus dénombrés, neuf passaient vers le nord-est ou étaient plutôt stationnaires. Le Fou de Bassan devrait logiquement encore continuer d’arriver ces prochaines semaines, et c’est bien plus tard en saison (janvier/fevrier) qu’on voit les plus gros effectifs, parfois quelques centaines, dans les eaux dakaroises.
  • Fou brun (Brown Booby): vu sept fois, dont trois individus en vol vers le sud-ouest et quatre vers le nord-est: difficile de parler d’un passage migratoire, peut-être plutôt des oiseaux stationnant aux Iles de la Madeleine et partant en mer pour pêcher? Tous les oiseaux étaient des immatures.

La suite de cette synthèse sera publiée dans quelques jours si tout va bien. Vous y trouverez limicoles, labbes, mouettes et goélands, sternes et guifettes, et quelques autres piafs encore.

 

 

 

Advertisements

Short-eared Owl in Senegal

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 two more records in recent weeks, with 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!).

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 (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.

Surely there are others 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.

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? I tend to lean to the latter, since it’s unlikely that there is a real increase in numbers given its overall rather precarious conservation status in Europe. Short-eared Owl is known to have highly fluctuating population trends and tends to be a nomadic species in many 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.

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 (again, a coincidence? With now five records in just four weeks we can almost talk of an influx in Senegambia this year!).

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 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 with records supplied by  Oliver Fox and Jos Hooijmeijer (many thanks!)

 

 

Another Lesser Yellowlegs (Chevalier à pattes jaunes)

Quick note today to report on the first Nearctic vagrant of the season: a Lesser Yellowlegs, seen yesterday at the Yenne-Todé lagoon.

After a very productive few days at Guereo, Bandia, and Popenguine – more on this later – I made my way back to Dakar via Yenne, the first village on the north end of the Petite Cote. I’ve known for a while that there’s a good lagoon here, but never visited at the right time of the year. A few weeks ago, Miguel had a great morning at the site (105 species including Dwarf Bittern, Spur-winged Goose, lots of Garganey), which prompted me to go see what’s about at the moment… Expectations were high, and I wasn’t disappointed: hundreds of ducks, many herons, a few gulls and quite a few terns, and most of all an incredible diversity of waders: 26 species!! Almost all regular migrant waders plus several of the local species were noted, some of which in decent numbers (e.g. nearly 30 Marsh Sandpipers, a few hundred Little Stints and Common Ringed Plovers, +120 Ruff). The site, which apparently is called the Niayetir lagoon, is easily accessible from different sides, mainly along the road coming from Toubab Dialaw but also from the village itself.

After I visited the main wetland just north of the road to Yenne, I stopped at the lagoon just behind the village, along the road back to Bargny. While scanning the numerous waders, I noticed a medium-sized wader with bright yellow legs: Yellowlegs!! It was actively feeding amidst the other waders, close enough to get good views through the telescope, but just a bit too far for decent photos…

LesserYellowlegs_YenneTode_20171113_IMG_5774

Lesser Yellowlegs / Chevalier à pattes jaunes

 

Its flashy yellow legs made it stand out against all other waders here (bird names don’t need to be complicated!). Identification as Lesser Yellowlegs was pretty straightforward thanks to its relatively fine bill about equal to the length of the head, as well as overall structure. The straight all-dark bill of medium length and fairly uniform brown-grey breast and upperparts, as well as the smaller size and more slender appearance, distinguish it from the much rarer Greater Yellowlegs (which has never been recorded in Senegal). Moreover, the size of this bird was roughly the same as Marsh Sandpiper with which it was seen side by side, just slightly bulkier and with a marginally heavier bill. The Marsh Sandpiper is just about visible on the picture below:

LesserYellowlegs_YenneTode_20171113_IMG_5788

 

A long-distant migrant, Lesser Yellowlegs mainly breeds throughout Canada and Alaska, and winters in a variety of wetland habitats from coastal areas of the US all the way down to the southernmost tip of South America (Tierra del Fuego). It is a rare vagrant to West Africa, with only six previous records in Senegal that I’m aware of, all of single birds between August and March:

  • 6-7/1/91 at Hann, Dakar, “Feeding with Ruff, Wood Sandpipers and Marsh Sandpipers” (Sauvage & Rodwell)
  • 3/3/07 in the Djoudj NP (Julien Piette)
  • 18/3/13 at the Kaolack saltpans (Simon Cavaillès)
  • 3-12/1/15 at Keur Samba Han near Kaolack (Simon Cavaillès)
  • 15/8/15 at Technopole (BP)
  • 17/1/16 at Technopole (BP, Boris Droz, Jérôme Gremaud)

As such, it’s the second most frequently noted American wader in Senegal together with Buff-breasted Sandpiper. Only American Golden Plover has been seen more often, with 10 records so far; and if last winter’s trend continues then Buff-breasted Sandpiper will soon overtake Tringa flavipes (no less than four records of six birds were obtained between mid-November 2016 and early January 2017!)

Elsewhere in Africa, Lesser Yellowlegs has mostly been noted on the Cape Verde islands, and there are a handful of records from Mauritania (22/3/04 and 6/2/14), The Gambia (January 1976, 13/10/08; possibly others), Ghana (at least two, incl. on 16/10/08), and Nigeria (Feb.-March 1969). Further north it’s been reported from the Canary Islands, Madeira, Morocco, and Tunisia. There are also a few records from South Africa (including one on Tristan da Cunha island in the South Atlantic), Namibia, and even Botswana.

LesserYellowlegs_YenneTode_20171113_IMG_5770

 

I’ll try to go back over the weekend and see if it’s still around – and why not find another Yank this time!

 

 

Audouin’s Gull in Senegal (part II)

(in case you missed the first part, you may want to read this post first)

Ring recoveries

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].

AudouinsRingSites_2017

 

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 birds, 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?

 

Age composition

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.

AudouinsGull_Technopole_20170312_IMG_0486

Audouin’s, Lesser Black-backed, Yellow-legged & Slender-billed Gulls

 

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.

AudouinsGull_Palmarin_20160820_IMG_4780_edited

66P, seen here in a rather unflattering position in August 2016 at Palmarin, was ringed as a chick in June 1999 in the Ebro colony

 

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.

AudouinsGull - Age graph

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!

 

Audouin’s Gull in Senegal: status, trends & origin (part I)

When I started birding nearly 30 years ago, Audouin’s Gull was one of those near-mythical birds, endemic to the Mediterranean and listed as an Endangered species on the IUCN Red List. Plus, it’s a real pretty gull, much more attractive than the standard “large white-headed gull”. Fortunately, this highly coastal species has seen substantial increases in its breeding population and has (re)conquered new localities, mostly during the nineties.

It is now found in Portugal (where it didn’t used to breed 30 years ago), Spain (where the bulk of the population breeds), France (Corsica), Morocco, Algeria, Tunisia, Italy, Croatia, Greece, Cyprus, and Turkey. The largest colonies are in the Ebro delta (14,177 in 2007) and the Chafarinas islands off NW Morocco (2,700 pairs in 1997). The Ebro colonies now represent about two thirds of the global population, so it is particularly of note that the species wasn’t even breeding there in 1980: Audouin’s Gull established itself in 1981 when 36 pairs bred, with as many as 4,300 in 1990, +10,000 pairs in 1993… and now certainly more than 15,000 (I didn’t immediately find any recent figures).

The species’ global population is now thought to number 63,900-66,900 individuals, with 21,300-22,300 breeding pairs: to write that this is “a significant increase from an estimated population of 1,000 pairs in 1975” certainly is an understatement… This remarkable feat is thought to be a result of the increased availability of effectively protected areas during the 1980s and of discarded fish from trawlers, particularly around the Ebro delta. Although it may still be vulnerable due to its small number of colonies, it was downlisted to “Least Concern” during the 2015 revision of the Red List, previously being considered Near Threatened (2004), “Lower Risk/conservation dependent” (1994), and Threatened (1988) (IUCN). Quite a conservation success story.

Following a good harvest of ring readings a few weeks ago in the Saloum delta, I wanted to find out a bit more about its history, trends, abundance and distribution in Senegal – and decided to turn it into a blog post here. This wasn’t too difficult given that a ton of research has been done on Audouin’s Gull, resulting in decent knowledge on its population dynamics and structure, distribution, breeding ecology, dispersal, feeding and migratory strategies, etc. The main challenge was to identify the most relevant resources and to distill everything into something relatively concise. And for once there’s even fairly abundant literature on the species in its wintering grounds here in West Africa.

First, let’s have a look at historical records of Audouin’s Gull in Senegal, and see if we can reconstruct the trends for the country.

audouins

Part of a flock of Audouin’s Gulls at Technopole (P. Robinson)

 

The ’60s and ’70s – the first records for Senegal

We automatically turn to our rapidly deteriorating copy of Morel & Morel (1994), who only list a handful of records – essentially, the first four records for the country:

An immature collected at Saint-Louis, 11/5/61 and an adult seen on Gorée island (Dakar) on 13/3/64; one photographed at “the entry of the Sine-Saloum” [wherever that may be! I assume near the Saloum river mouth?] on 1/2/75, and one record near Dakar at the end of December 1981.

Dupuy (1984) adds the observation of an adult in the north of the Saloum delta on 13/12/80 but this record was either overlooked, or not retained by M&M. Interestingly, De Smet & Van Gompel (1979) did not encounter the species even though they covered large chunks of the coast between lac Tanma and the western Saloum delta, as well as the Senegal river delta, during the 1978/79 winter. This seems to confirm that Audouin’s Gull at the time was still a rare or very scarce visitor here – something which was about to change very soon.

The ’80s and ’90s – establishment of a wintering tradition

Moving on, Sauvage & Rodwell (1998) consider Audouin’s Gull to be “frequent at PNLB (Langue de Barbarie NP) and Saint-Louis, Jan.-Apr. with max. 17 birds, Jan. 1994, nine ringed in Spain. Up to 10 were wintering around Saint-Louis, 1990-91.” It is “frequent to common Dakar off Pointe des Almadies and Toubab Dialao, Jan.-Mar., max. 104 (four ads.), Toubab Dialao, Jan. 1992. Frequent to abundant Saloum delta. Max. 321 wintering.” The latter figure, obtained in 1985 (Baillon 1989) is significant as it is the first mention of a substantial number of birds in Senegal, and can likely be linked to the “explosion” of the Ebro delta colony. In Jan.-Feb. 1988, Delaporte & Dubois counted gulls all along the Senegambian coast, from the Mauritanian border to Casamance, and counted 81 Audouin’s Gulls (6 near Saint-Louis, 3 along the Petite Cote, 72 around Palmarin) though they estimate a total of 130 birds. They also mention the presence of 185 in the northern Saloum (probably Palmarin/Joal-Fadiout) on 6/12/88. Del Nevo et al. (1994) conducted counts in February 1991 and in September-October 1992, noting a total of 459 birds in Senegal and 72 in Gambia (1991), and 276 in Senegal the following year, mainly at Sangomar and Joal-Fadiouth.

A few eBird records from the early nineties provide some more context for that decade, in particular the count of no less than 470 birds at the Somone lagoon on 28/2/91, with two at Mbodiene (south of Mbour) a couple of days earlier, and 12 at Plage de Hann (Dakar) on 18/2/91 (O. Benoist). Bengtsson (1995) reports a minimum of 456 near Palmarin in Nov.-Dec. 1994. Based on these records, it looks like the species became a regular winter visitor to Senegal in the early to mid ’80s, and rapidly established a number of traditional wintering areas during that decade.

The next comprehensive figures are reported by Schepers et al. (1998) based on waterbird counts from January 1997 in the Saloum delta and along the Petite Côte. The team counted a total of 858 Audouin’s Gulls between Dakar and the delta, with the majority (673) found in the Saloum, and 185 along the Petite Côte. They estimated the wintering population to number around 1,000 birds, while in 1988 the same areas (incl. Saint-Louis) held at least 80, but more likely at least 130 Audouin’s Gulls (Delaporte & Dubois 1990, though Baillon & Dubois in 1991 estimated the number of wintering birds to be around 500, without providing further details). Regardless, these numbers suggest that Ichtyaetus audouini continued to increase in numbers throughout the late eighties and nineties, and confirmed that Senegal plays an important role for the species during its non-breeding cycle.

AudouinsGull_Palmarin_20170903_IMG_4366

2000 – 2017 – stability

Fast-forward a few years to the first decade of the 21st century: hardly any published data! The only citations of the species that I could find are from seawatch sessions and a few trip reports. For instance from 2006, when a Swedish team counted migrating birds off Ngor, from 10–14 and 25–26 November: 28 Audouin’s Gulls were noted on three separate days (Strandberg & Olofsson 2007). A year later, a more comprehensive migration study at Ngor, with impressive numbers of seabirds counted from 5-28 October, resulted in a total of 692 birds. In the Senegal delta, a maximum of c.15 birds were counted in 2002 (Triplet et al. 2014).

In January 2011, some 50 Audouin’s Gulls were counted by Ottvall et al. at Lac Rose, providing “more evidence of the increasing numbers […] wintering along the coast north of Dakar.” Later that year, Paul Robinson reports two 2nd calendar years from Lac Tanma, which seems to be the first mention of the species here (I’ve seen two birds on 28/8/16 here, but not during other visits in 2015-17). Paul also recorded the species in Popenguine, where on 12/2/12 the pond had “a few” Audouin’s gulls amongst the gulls.

In July 2012, Paul counted c.150 Audouin’s Gulls at Technopole, noting that these were “all sub-adult birds from 2010 and 2011, represents a real increase in summering birds south of the Sahara and a West African summer record count. Several had Spanish rings.” Indeed, Audouin’s Gull can now be seen year-round in Senegal.

Ngoné and colleagues estimated the Palmarin “winter” population to number 445 individuals (278 adults, 167 immatures) based on the modelling they performed on their monthly counts and ring recoveries from the end of 2013 up to end 2015. This seems rather on the low end given that at peak times in October they recorded up to around 700 birds, and that in recent years it’s easy to find more than 300 birds together in the lagoons along the Samba Dia road – surely there are many others scattered throughout the western Saloum delta, e.g. around Sangomar and further south. More on the findings of their study, which was presented under the form of a poster at last year’s PAOC, will be discussed further down.

Current distribution in Senegal

The winter range of the species in Senegal probably hasn’t changed much in the last 20-30 years, with the following areas being regularly used by Audouin’s Gulls:

  • La Grande Côte: Langue de Barbarie and elsewhere in the Senegal delta around Saint-Louis (shores, beach and lagoons), though never in large numbers, with a maximum of c.65 birds in Jan. 2013 (Triplet et al. 2014). On the southern end of the coast, the species is regularly seen at Lac Rose and sometimes at Lac Tanma. It probably also occurs along the beach throughout (I need to ask Wim about this!), especially around the larger fishing towns and villages: Kayar, Mboro, Lompoul, etc.
  • Cap-Vert peninsula: Regular at Lac Rose (e.g. c.60 on 8/8/15, 2 on the beach on 22/1/17, 5 on 14/5/17) and Technopole, where most numerous in January-March, but records from all months except for September (when I rarely visit Technopole); so far my highest count has been a modest 50 birds on 12/3/17. Birds are also regularly seen from Ngor, either migrating or, more often, feeding out at sea. In autumn and winter, one should be able to see Audouin’s Gull pretty much all along the coast from the Pointe des Almadies along Yoff all the way to Lac Rose. I really need to check out the Hann bay from time to time, as there are often lots of gulls and terns. The species has also been reported from Yene-Bargny where is likely still a regular visitor, and may well be numerous at times (in autumn maybe? Birds may favour Technopole later in winter).
  • La Petite Côte: the Somone lagoon seems to be the most regular site, but birds also show up at least irregularly at Popenguine and Mbodiene, and likely feeds off-shore along the entire coast here.
  • Saloum delta: this is of course the main wintering area, that likely holds about 80% of the Senegalese wintering population. Birds are typically concentrated in the lagoons to the north of Palmarin, and do not gather far inland. It should also occur further south in the delta but I have no data from there.
  • Coastal Casamance: the only record I know of is of two birds on 12/10/16 flying north along the beach at Diembering. There certainly are more records (though none on eBird nor observado.org) as Casamance must be the far end of their regular range, given the absence of sightings in nearby Guinea-Bissau.

In terms of population size, my own conservative guestimate puts the current number on 800-1,000 birds, so not any different than the 1,000 birds estimated to winter in Senegal in January 1997, which logically reflects the species’ stable global population trend.

AudouinsGull_Palmarin_20170903_IMG_4376

Audouin’s & Lesser Black-backed Gulls with Caspian Terns at Palmarin, Sept. 2017

 

Elsewhere in West Africa

Isenmann et al. (2010) enumerate lots of records for Mauritania, but little or no info is provided on the evolution of the wintering population in the country, probably because of a lack of historical data. The current status is that of a regular migrant and wintering bird, with at least several hundreds of birds along the coast. Far more birds are said to winter along the Western Sahara coastline. The Gambia is also part of its regular winter range, mainly on and around the Bijol Islands, Tanji Bird Reserve. In 2007/08, about 500 Audouin’s Gulls were counted there. The first Gambian record, as per Morel & Morel, is of a bird at the Bakau Lagoon on 21/2/82.

Surprisingly, the species hasn’t yet been seen in Guinea-Bissau, which is most likely right outside the regular winter area, but surely a few individuals must reach the NW corner of the country, and particularly the Bijagos, given that they are recorded at least from time to time (it would seem) in Casamance and that Gambia is less than a 100 km away from the border. My Oct. 2016 observation near Diembering was barely 20 km from the border and both birds were moving north… In Guinea, the first record was obtained just last year by gull expert Peter Adriaens, a first-winter near Cap Verga on 28/10. The lack of other records from Guinea (and Guinea-Bissau) most likely reflects the absence of observers in the country, rather than a real absence of Audouin’s Gull which surely must at least from time to time reach Guinean waters. This is not the case in relatively well-watched Ghana, where the species is a true vagrant: a first-winter on 13/1/14 was quite an unexpected first for the country, as it had not previously been reported south of Senegambia (Kelly et al. 2014). [note that the species certainly doesn’t winter in Gabon, contra BirdLife International’s species fact sheet].

AudouinsGull_Palmarin_20170903_IMG_4329

 

Now, I still wanted to talk about the origin of wintering birds in Senegal and summarise current knowledge based on ringing recoveries, but my blog post is already getting a bit long… that part will have to wait for a second installment, hopefully a week or two from now.

 

 

La Garden Liste

Tout birder qui se respecte tient une petite liste des oiseaux qu’il ou elle a vu ou entendu dans son jardin: la garden list.

Après deux ans et demi passés dans notre quartier aux Almadies, et avec plusieurs firsts pour ma liste ces dernières semaines (dont trois dimanche dernier!), je me suis dit que c’était l’occasion de faire le point. Ne tenant pas de liste proprement dite – autrement que dans ma tête – j’ai donc fouillé dans mes archives et j’en ai profité pour extraire mes données brutes, les rattacher aux lieux-dits moyennant quelques operations dans QGIS, puis de les synthétiser afin de les présenter ici pour la postérité, rien que ça.

Pour se situer, voici une petite carte de l’Ouest dakarois avec mes observations de ces deux dernières années, soit plus de 5’000 données pour la zone montrée ci-dessous (toutes saisies avec l’excellente application Naturalist, cela dit en passant) :

Blog_Dakar_obs_carte

Résultat des courses, sur la base de mes quelques 1’800 observations “jardin”, je peux vous annoncer que j’ai pu rencontrer quelques 71 espèces autour de chez nous. Je dis bien “autour” car n’ayant pas vraiment de jardin, je considère tout oiseau vu ou entendu depuis chez moi comme faisant partie de ma garden list.

Tout d’abord un oiseau vu et surtout entendu de temps en temps, généralement de nuit ou tôt le matin: le Dendrocygne veuf (White-faced Whistling Duck), survolant la maison (avril et deux fois en septembre, en 2016). Deux autres espèces qu’on voit parfois passer en vol sont le Cormoran à poitrine blanche et le Cormoran africain (White-breasted, Long-tailed Cormorants), ce dernier ayant été vu une seule fois pour l’instant (2 inds.  le 11/5/16). De même, peu d’ardéidés sont vus, principalement le Héron gardeboeuf (Cattle Egret), suivi par le Bihoreau gris (Black-crowned Night-Heron) qui semble régulier en migration au printemps (mi-février à début avril), quand on peut entendre son cri de contact caractéristique, toujours de nuit comme il se doit. Le Héron pourpré (Purple Heron) quant à lui a été entendu le soir du 17/9/17, certainement un voire plusieurs oiseaux en migration active.

L’une des grandes surprises de la liste est un oiseau qui n’a rien à faire à Dakar, étant restreint au tiers méridional et oriental du pays: l’Ibis hagedash (Hadada Ibis): le matin du 23/8/17, j’entends un oiseau passer pile au-dessus de la maison, puis j’ai pu le voir dans le jumelles in extremis, avant qu’il ne disparaisse derriere les immeubles. Heureusement qu’il a crié celui-là, sinon je l’aurais loupé… Ma seule autre observation dans la région est celle d’au moins deux oiseaux le 9/8/15 au Lac Rose.

Les Vautours charognards (Hooded Vulture), je vous en ai déja parlés ici et , mais je rajoute tout de meme une petite photo histoire d’aérer un peu cet article un peu. Ci-dessous, un adulte (à droite) et un jeune.

HoodedVulture_Almadies_20160303_IMG_2341

De temps en temps, un ou deux Balbuzards (Osprey) tournoient au-dessus de la maison, alors que le Milan à bec jaune (Yellow-billed Kite) est évidemment très commun; il y a certainement plusieurs couples aux alentours. Debut janvier 2017, c’est un rapace bien plus imposant et tout a fait inattendu qui a fait escale dans les eucalyptus juste derrière la maison: un Aigle ravisseur (Tawny Eagle)! Arrivé en fin d’après-midi du 5/1 (alors non vu, mais le boucan énorme des corbeaux a annoncé sa présence), c’est le lendemain matin que je me rends compte qu’il est toujours là et qu’il a dû passer la nuit à moins de 50 mètres de la maison! Du côté opposé du spectre des rapaces, l’Epervier shikra (Shikra) est vu de temps en temps: à part un ind. le 2/12/15 toujours en septembre et octobre, dont ce jeune individu photographié tout récemment depuis le balcon:

Shikra_Almadies_20170916_IMG_4653

Dernier rapace sur la liste, le Faucon chicquera (Red-necked Falcon) qu’on voit parfois chasser à toute vitesse dans le quartier. Il semble nicher non loin, vers la Pointe des Almadies où il y a beaucoup de vieux cocotiers.

Le Vanneau éperonné (Spur-winged Lapwing) est présent en petit nombre dans le quartier, mais ce sont surtout les bruyants Oedicnèmes du Sénégal (Senegal Thick-knee) qui se font bien remarquer, des la nuit tombante et jusqu’au petit matin: à écouter ici! Voila un chant que j’associerai sans doute pour toujours avec notre sejour au Sénégal. Viennent deux limicoles migrateurs ensuite, chacun vus une seule fois pour le moment: le Courlis corlieu (Whimbrel) vu le 11/9/15; le Chevalier culblanc (Green Sandpiper) le 17/9/17 lorsqu’un oiseau survole la maison en criant. Certainement un migrateur qui a dû se poser quelque part dans les environs en fin de nuit, puis qui s’est fait déranger.

L’océan n’étant qu’a quelques pas, de temps en temps j’entends ou je vois des sternes survoler la maison: la Sterne royale (Royal Tern) à plusieurs reprises entre mars et juillet; la voyageuse (Lesser Crested Tern) uniquement le 17/3/17 (3 inds.).

Le Pigeon roussard (Speckled Pigeon) est commun et niche quelque part dans le bâtiment (sous le toit?). L’autre jour j’ai pu contstater la présence d’au moins un gros juvénile, à comparer avec le parent (photo du bas):

SpeckledPigeon_Almadies_20170916_IMG_4662

SpeckledPigeon_Almadies_20170916_IMG_4660

Encore plus commune, la Tourterelle maillée (Laughing Dove); par contre la présence d’une Tourterelle rieuse (African Collared Dove) les 16 & 18/12/15 était tout à fait inattendue (après coup je me demande s’il n’a pu s’agir d’une Tourterelle turque, option que je n’avais même pas considérée à l’époque car c’était bien avant la découverte de la petite population du parc de Hann).

Si la Perruche à collier (Rose-ringed Parakeet) n’est vue que de temps en temps (2-4 fois par mois peut-être), le Perroquet youyou (Senegal Parrot) s’observe quasi quotidiennement, généralement tôt le matin lorsqu’ils quittent un dortoir dans les environs, ou encore le soir survolant la maison en criant.

Senegal Parrot / Perroquet youyou

Le Touraco gris (Western Plantain-eater) est courant à toute saison, et toujours bien bruyant! Généralement 2-3 oiseaux ensemble, rarement plus.

Trois coucous se trouvent sur ma petite liste: le Coucal du Senegal (Senegal Coucal) bien sûr (surtout entre juin et novembre? Présence variable d’une année à une autre), mais aussi une fois un Coucou didric (Diederik Cuckoo) entendu chanter le 28/7/17, puis – grosse suprise! – un jeune Coucou-geai (Greater Spotted Cuckoo) entendu puis vu le 21/6/17.

On a la chance d’avoir au moins un couple d’Effraies des clochers (Barn Owl) dans le quartier, oiseaux qui ont du nicher dans une maison voisine l’an dernier car les jeunes une fois émancipés se sont installés sur (et sous?) le toit de la maison d’à coté: à écouter ici; bref article . Plus étonnant, un Petit-duc à face blanche (Northern White-faced Owl): se fait entendre le soir du 24/1/17, alors que Simon et moi sirotions tranquillement une biere sur la terasse… probablement dans les eucalyptus derrière la maison.

Les Colious huppés (Blue-naped Mousebird) se font souvent entendre lorsqu’ils rôdent dans le quartier. Le Martinet des maisons (Little Swift) niche bien sûr dans les environs et s’observe régulierement au-dessus de la maison; le Martinet noir (Common Swift) par contre n’a été vu qu’une seule fois pour le moment, le 3/5/16. Il faut dire que cette espèce est étonnament peu vue à Dakar, sans doute parce que la plupart des oiseaux en transit passent plus a l’intérieur du pays, ou longent la côte mais couperaient alors à travers la péninsule du Cap-Vert (hypotheses et spéculations! il se peut aussi qu’ils migrent simplement trop haut dans le ciel pour les détecter). Le Guêpier nain (Little Bee-eater) s’arrête parfois quelques jours sur les terrains vagues aux alentours de la maison (notamment entre la mi-mars et mi-mai 2016); un Rollier d’Abyssinie (Abyssinian Roller) a fait escale le 18/8/16.

Aussi bien le Calao à bec rouge que le Calao à bec noir (Western Red-billed & African Grey Hornbills) sont présents dans l’agglomération, mais ne sont pas communs et semblent surtout fréquenter les parcs et grands jardins: dans notre quartier, je ne les vois que de temps à autre, et plutot celui à bec noir, hors période d’hivernage. Le petit Barbion à front jaune (Yellow-fronted Tinkerbird) est un visiteur occasionnel chez nous, avec pour l’instant juste une obs auditive le 29/8/17; je l’entends de temps à autre du côté de Fenêtre-Mermoz vers l’école des enfants, et ce uniquement en saison des pluies. Le Pic gris (African Grey Woodpecker) fait des incursions de temps à autre et se fait lui aussi remarquer par son cri caractéristique, et semble assez repandu dans les quartiers les plus arborés.

Les Hirondelle de Guinée (Red-chested Swallow) font désormais partie du paysage aviaire du quartier, alors qu’en 2015 cette espèce faisait plutot défaut. Elles doivent nicher dans les environs immédiats car elles chantent, viennent chasser, se posent sur les fils… et le 3/6/17 il y avait au moins deux jeunes recemment émancipés; l’Hirondelle rustique (Barn Swallow): janvier, février, octobre 2016. Autre migratrice, la Bergeronnette printanière (Yellow Wagtail) survole la maison le 24/11/16.

Présent tout au long de l’année et souvent le première espèce à chanter le matin, parfois avant meme l’aube, le Bulbul des jardins (Common Bulbul) mérite bien son nom. Le Gonolek de Barbarie (Yellow-crowned Gonolek) se fait bien plus discret et a besoin d’un peu plus de buissons.

La Fauvette passerinette (Western Subalpine Warbler) ensuite, vue plusieurs fois au printemps 2015 dans ces mêmes arbustes, puis le 4/3/17 dans les fourrés en face du portail. Le Pouillot fitis (Willow Warbler) s’observe irrégulièrement, surtout depuis que les gros buissons sur le terrain voisin ont été coupés pour y construire encore une grosse baraque (+ 17/9/16); le Pouillot véloce (Chiffchaff) a fait une escale, en chantant, le 1/12/15.

La Cisticole des joncs (Zitting Cisticola) ensuite: un chanteur lance son tsit!…tsit!…tsit!… explosif les depuis dimanche dernier dans le terrain vague juste à côté. C’est lors de la saison des pluies que les oiseaux sont les plus vocaux ici, et je l’entends souvent p.ex. aux abords du futur ex-aéroport, ou encore entre les Mamelles et Ouakam, mais c’est la première fois que j’ai un oiseau en pleine zone résidentielle… faut dire que l’espèce est vraiment peu exigeante ici! Ceci vaut encore plus pour les Prinias modestes et Camaropteres à dos gris (Tawny-flanked Prinia, Grey-backed Camaroptera), deux piafs omniprésents sur le continent et que je vois tout au long de l’année. Le Crombec sittelle (Northern Crombec) par contre est bien moins typique des jardins urbains, mais en 2015 de temps en temps je l’entendais chanter dans les arbres aux environs. On le trouve fréquemment au Parc de Hann ainsi qu’au Technopole, par exemple. Le Gobemouche noir (Pied Flycatcher) s’arrête parfois dans les grands arbres aux alentours, notamment en septembre quand il se fait remarquer par ses cris de contact constants.

J’ai encore un peu de mal à saisir les mouvements des souimangas ici, avec deux espèces régulieres et une occasionnelle (le Souimanga cuivré Copper Sunbird est vu le 5/9/15 mais plus jamais depuis): le Souimanga à longue queue (Beautiful Sunbird), plutot visible en fin de saison sèche et début d’hivernage, et le Souimanga variable (Variable Sunbird); qui lui semble plutot arriver en septembre/octobre, timidement d’abord, pour rester tout au long de la saison sèche, jusqu’à début juin.

VariableSunbird_Almadies_20160502_IMG_3150

Les Choucadors à longue queue (Long-tailed Glossy Starling) se font très régulierement entendre, parfois – comme ce fut le cas lors de l’hivernage 2015 – de nuit, lorsque certains oiseaux se mettent à chanter à tue-tete pendant des heures et des heures (oui on a souffert!!). L’autre représentant des sturnidés sur notre liste est le Choucador à ventre roux (Chestnut-bellied Starling), avec une observation étonnante d’onze individus passant en vol devant la maison le 25/3/16. Cette espèce ne se rencontre pas habituellement en ville, mais il y a visiblement une petite population (résidente?) dans les jardins de l’hôtel King Fahd où ils fréquentent les pelouses du terrain de golf.

Ensuite deux espèces commensurales, omniprésentes à Dakar: le Corbeau pie (Pied Crow) et le Moineau domestique (House Sparrow). L’histoire de ce dernier est fascinante, ce petit moineau ayant réussi à conquérir une bonne partie de la planète – une progression qui d’ailleurs est toujours en marche, du moins sur le continent africain où il reste encore beaucoup de villes à coloniser. Arrivé sans doute au tout debut des annees 1970, “provenant vraisemblablement de l’Afrique du Sud” (Morel & Morel 1990), Passer domesticus a petit à petit conquis les villes et villages du nord du pays (premier couple nicheur à Saint-Louis en 1979), le long de la Petite Côte et même jusqu’à Tambacounda où sa présence fut confirmée tout récemment. Si le corbeau niche dans un palmier juste en face, les moineaux s’installent dans des trous dans les murs ou dans le toît, sous les tuiles (3-4 couples dans notre maison). Le Moineau gris (Grey-headed Sparrow) par contre ne semble pas très bien se maintenir en ville, car je ne l’observe que de temps en temps et jamais plus de deux oiseaux (des couples?) ensemble. Le petit Moineau doré (Sudan Golden-Sparrow) se montre plus rarement encore, généralement associé à des groupes de Travailleurs à bec rouge (Red-billed Quelea) et plutôt en saison sèche (surtout février – mai). Toujours dans le meme registre, les Tisserins: le minule est vu de temps en temps, alors que le gendarme et surtout celui à tete noire sont bien plus courants, nichant à proximité de la maison (Little, Village, Black-headed Weavers).

C’est presque fini! Reste plus que les petits granivores tels que le Combassou du Sénégal (Village Indigobird), charmant petit parasite qui en ce moment, lors des pluies, est présent quotidiennement.

VillageIndigobird_Almadies_20170829_IMG_3927.

Je ne sais pas en fait si les Amarantes du Sénégal (Red-billed Firefinch), présentes toute l’année, s’en rendent bien compte qu’ils se font avoir par le combassou! Une seule obs de Cordon-bleu à joues rouges (Red-cheeked Cordonbleu), le 12/12/16 (il y a une petite population non loin, dans les jardins du King Fahd). Parmi les oiseaux urbains les plus répandus à Dakar figure le sympathique Capucin Bec-d’Argent (African Silverbill), voir photo d’en-tête. Le Capucin nonnette (Bronze Mannikin) est présent en nombre variable et plutôt en saison des pluies. Puis last but not least, espèce numéro 71: le Serin à croupion blanc (White-rumped Seedeater)!

 

p.s. du 24/9: la nuit dernière, encore une espèce est venue s’ajouter à la liste: quelques Guifettes noires passent au-dessus de la maison, en criant, peu après minuit!

 

 

A Mystery Shrike

Yesterday, Gabriel and I paid a visit to Lac Tanma – our first of the season and of what will hopefully be a series of regular visits there.

We’d barely arrived near the lake, after a couple of failed attempts to find a driveable track towards the lake (too muddy!), when we noticed a shrike sitting on top of a thorny bush. The overall appearance was that of a fairly large, greyish shrike, but quite a few things were just wrong for a Southern Grey Shrike (which given the time of the year would have been surprising to see here, as it typically shows up between December and February/March).

Suspecting a hybrid, we took a number of pictures before the bird flew off, which allowed us to compare with photographs and descriptions of known hybrids. I vaguely remembered that a few years back (it turns out this was in 2010) a similar hybrid had been reported from the French Jura, and that there was a drawing of another French bird in the excellent Shrikes – A Guide to the Shrikes of the World (Lefranc & Worfolk 1997).

This is what our bird looked like:

WoodchatxRedbackedShrike_LacTanma_20170826_IMG_3911

 

In typical shrike fashion, this bird had a distinctive black “Zorro mask” with an otherwise grey head and largely grey back (faintly mottled brown); white scapulars; black wings with a fairly large, elongated off-white patch at the base of the primaries; entirely pale salmon-pink underparts (from the throat all the way to the vent); and a white rump contrasting with its long black tail. In the field we noted some narrow pale borders to tertiaries, but these are not well visible in the pictures.

While a lot of hybrids between two bird species typically resemble both parents in one way or another, showing intermediate characteristics, this is not the case here. Our bird superficially looks like a Southern Grey Shrike, but clearly isn’t one: the buffish underparts especially, but also the seemingly all-dark tail (no white outer rectrices) and the lack of distinct white markings on the tertials and secondaries. Moreover, the structure and size – even though our bird seemed quite large – were not right for Southern Grey which is larger and more powerful (cf. a couple of pictures taken last winter in Palmarin). The same pretty much applies to Lesser Grey Shrike, which in addition has a black mask that extends to the forehead and lacks the white scapulars.

So who are the parents? Based on comparisons with pictures of hybrid shrikes and with the drawing and description in Lefranc & Worfolk, these types of birds are considered to be hybrid Woodchat x Red-backed Shrikes. The former is the most common Palearctic shrike species in Senegal, while the latter doesn’t usually occur in West Africa. The black mask, grey head, and “pinkish-white” underparts are typical of Red-backed, while the white scapulars, rump and wing patch are indicative of Woodchat. The grey back is a bit odd but has also been observed on other presumed hybrids with these two species as parents, and the faint brownish mottling hints at a hybrid origin. Another option would be a hybrid Woodchat x Lesser Grey Shrike, though there’s apparently only one such suspected bird that has been observed, in Hungary in 1979 (Handbook of Avian Hybrids of the World, McCarthy 2006). Much less likely, and one would expect at the minimum a black front on such hybrids¹.

WoodchatxRedbackedShrike_LacTanma_20170826_IMG_3916

Woodchat x Red-backed Shrike / Pie-grièche à tête rousse x écorcheur

WoodchatxRedbackedShrike_LacTanma_20170826_IMG_3921

Woodchat x Red-backed Shrike / Pie-grièche à tête rousse x écorcheur

WoodchatxRedbackedShrike_LacTanma_20170826_IMG_3917

Woodchat x Red-backed Shrike / Pie-grièche à tête rousse x écorcheur

 

Now compare our bird with the painting of a hybrid noted in France in 1995, fig. 26g:

IMG_3926

Source: Lefranc & Worfolk (1997)

Comments on the identification of this bird are more than welcome of course!

As far as I know, this is the first record of such a hybrid in (West) Africa; all other published data are from birds on migration or on breeding grounds in Europe. In recent years there’s been one such bird in Switzerland (April 2014), one in the French Lot department (May 2014), while hybrid males have bred (successfully!) with female Red-backed Shrikes in  2005 in South-East Belgium (short note available in PDF here), and in 2010 and 2011 in France. Pictures of the 2010 Jura bird can be found e.g. here and here. At least 12 mixed pairs have been found in France, but it seems that nothing is known on the whereabouts of these birds outside the breeding season: do they migrate to East Africa just like Red-backed Shrikes, or can they be found anywhere in Woodchat Shrike’s wintering grounds? Lefranc & Worfolk describe the latter as “a vast belt running across the African continent just south of the Sahara and largely north of the huge forest areas”. Our observation would suggest that they can show up anywhere in that area.

Other than our peculiar shrike, we had a pretty good morning out birding, with close to 100 species seen. Lac Tanma didn’t hold an awful lot of waders (a few hundred only, mostly Black-winged Stilts) but we did confirm breeding once again of Kittlitz’s Plover, while a female Knob-billed Duck also showed signs of breeding as it was seen flying around several times (and sometimes calling, which is associated with courtship behaviour). There were about 250 Greater Flamingos (and ca. 220 more at lac Mbaouane), several Gull-billed, Caspian, and White-winged Terns, but very few herons. A surprise find was that of three Spotted Thick-knees on the edge of the lake’s floodplain, quite close to the main road. Several Diederik, African and Jacobin Cuckoos were seen or heard, as were a few Broad-billed Rollers (another wet season visitor) and a single Purple (=Rufous-crowned) Roller. As usual, Mosque Swallows were hawking insects above the lake shore and the baobab forest; the latter also had a singing Hoopoe and several Woodland and Grey-headed Kingfishers. Besides the shrike, the only European songbirds that we spotted were two Melodious Warblers.

A Purple Heron at a small marsh near the village of Beer was my first of the season; we also found African Swamp-hen, Red-eyed Dove, and African Thrush here. Lac Mbaouane was visited only briefly and we just scanned the NW side of the lake, which had a few dozen Common Ringed Plovers and some Little Stints, while a few Blue-cheeked Bee-eaters were flying over and a Red-necked Falcon dashed over the lake as it was hunting.

IMG_3923 (2)

Lac Mbaouane

 

(Regular readers will wonder what’s happening at Technopole. Well, I paid my first visit in three (!) weeks this morning, together with Theo. Water levels are rising with every shower, so conditions are getting less ideal for waders. Still a few hundred Ruffs, some Curlew Sandpipers, ca. 50 Sanderling and a few Little Stints, a handful of Black-tailed and a single Bar-tailed Godwit, Marsh, Green, Wood & Common Sandpipers, Greenshank, Redshank, a few migrating Whimbrels, etc. Also Shikra, a Hoopoe, and again a Broad-billed Roller to name but the most interesting records. The most unusual record this past week was actually one from Almadies: a Hadada Ibis flying over our house one morning! More on that one later, if I get the chance to write something up.)

 

¹ N. Lefranc mentioned that a mixed pair senator x minor was found in France last year. And that so far, no hybrid or mixed pairs senator x meridionalis have been recorded.