Tag Archive | migration

Seawatching Ngor – October & November 2019

We’re entering the final stretch of this year’s seawatch season, but before we wrap things up in a few weeks, it’s time for a quick overview of October and November. As for August and September, below is a comparison of the 2019 counts with those from the previous two years. Even if observer effort and coverage were quite different in those three years, it’s clear that there are important variations from year to year, both in terms of phenology and in terms of abundance of many of the seabirds that migrate past the Dakar peninsula. Prevailing weather conditions, and in particular dominant wind direction (and wind force), of course have a strong influence on the intensity of visible seabird migration, though other factors are also at play for certain species. Annual variations in breeding success of skuas are well documented and probably explain some of the annual differences that we see here in Dakar.

CalaoSeawatch_20191110

Essential seawatch equipment!

 

This year’s coverage was again pretty good for October (28 sessions on 24 days, similar to Oct. 2017) but less so for November (15 sessions on 12 days), though we did manage to do longer counts during both months, especially in November. But let’s start with October:

Species

2019

2018

2017

Cory’s/Scopoli’s Shearwater

86

0

232

Sooty Shearwater

631

1,035

2,534

Manx Shearwater

20

8

29

Shearwater sp.

24

4

22

Wilson’s Storm-Petrel

0

0 96

Northern Gannet

3 2

1

Brown Booby

0

1 0
Oystercatcher

24

20 18

Common Ringed Plover

2 0

5

Whimbrel

32 4

8

Bar-tailed Godwit

8

0 10
Turnstone

6

0 0
Ruff

0

0 12
Dunlin

0

0

2

Sanderling

16

6

0

Little Stint

6

0 0

Common Sandpiper

4 0

0

Greenshank

0 0

1

Common Redshank

3 5

0

Grey (Red) Phalarope

12

0 78

Audouin’s Gull

77 21

55

Lesser Black-backed Gull

3

18 2
Yellow-legged Gull

1

0

0

Large gull sp.

8 0

7

Slender-billed Gull

6

1 4

Grey-headed Gull

2 0

0

Sabine’s Gull

1,081

178 2,970

Arctic/Common Tern

3,768 1,094

4,296

Roseate Tern

6

14 54
Little Tern

65

7

78

Sandwich Tern

2,479

905 1,313

Lesser Crested Tern

299 113

150

African Royal Tern

457

198 57
Caspian Tern

22

20

9

Black Tern

1,059 333

2,735

Whiskered Tern

1

0 1

Bridled Tern

1 0

0

Bridled/Sooty Tern

1

0 0

Great/South Polar Skua

60 11

66

Pomarine Skua

763

85 1436

Arctic Skua

486 198

339

Long-tailed Skua

47

21 32

Skua sp.

476 182

1138

Total birds

12,045 4,484 17,880

Number of days

24

10

26

Number of hours

37h30′ 19h00′

28h20′

 

October was relatively quiet compared to previous years, mostly because conditions were not so favourable during the last 10 days of the month, hitting an absolute low on Oct. 31st when only 68 birds were counted in one hour… With hardly any wind, far fewer Sooty Shearwaters and Pomarine Skuas than usual were noted (Puffin fuligineux, Labbe pomarin). Most terns however were more numerous, possibly due to a later passage than in previous years, particularly for African Royal, Lesser Crested and Sandwich Terns (Sternes royales, voyageuses, caugeks). With just over 1,000 birds, the passage of Sabine’s Gull was fairly average though still very enjoyable on two days: 220 in 2h45’ on Oct. 12, and 315 in 3h20’ on Oct. 17 (Mouette de Sabine). Among the rarer species, an ad. Bridled Tern was seen on Oct. 12 (+ a distant Bridled or Sooty on Oct. 8; Sterne bridée).

Long-tailed - Pomarine Skua - DSC_2305 - B Mast

Pomarine & Long-tailed Skuas, off Ngor, Oct. 2018 (Bruce Mast)

 

November was a different story: with a fairly similar number of hours spent counting birds from the Calao terrace, almost double the number of birds were counted than in 2017. A much stronger passage was noted for many species: Cory’s/Scopoli’s Shearwaters (56,438 birds counted: almost twice the 2017 number and triple that of 2018!), Great Shearwaters, Sooty Shearwaters, Northern Gannets, and Pomarine & Arctic Skuas (Puffin cendré / de Scopoli, Puffin majeur, fuligineux, Fou de Bassan, Labbes pomarins et arctiques). Because we were present on less days but spent more time per session, it’s hard to compare with previous years, though it’s clear that at least some of these species were more numerous, such as the Gannets that passed through en masse from the 10th onward (max. 1,223 birds in 90’ on Nov. 20!), which is far earlier than in previous years when peaks were noted from the end of the month and in December. The higher number of skuas and Sooty Shearwaters are also at least in part explained by the later passage, properly starting only around November 10th rather than in the last week of October. Only one Long-tailed Skua was identified during this period, at the very start of the month, bringing this season’s total to 489 birds.

ScopolisShearwater_Ngor_20170415_IMG_1320

Scopoli’s Shearwater, off Ngor, April 2017

 

The peak passage of Cory’s/Scopoli’s Shearwaters took place during Nov. 10-16, with up to 4,020 birds passing through per hour during the morning of the 10th. While slightly less intense in previous years, the highly concentrated passage took place almost exactly during the same period. It’s really remarkable how this species pair is completely absent up to the very last week of October: the first 45 birds were seen on Oct. 28th with just a handful in subsequent days, then 638 in 1h15’ on Nov. 4th and 215 in 1h45’ the following day, then literally exploding just a few days later (unfortunately no observations were made during Nov. 6-9). Our counters nearly overheated, thumbs hurting! In comparison, the migration pattern of Sooty Shearwater for instance is very different, showing a very long and diffuse migration season (end August – mid December) without a clearly defined peak.

Corys-ScopolisShearwater_2019_daily_chart

Daily average number of Cory’s & Scopoli’s Shearwater per hour (2019). The dotted lines and grey markers indicate extrapolated data; red markers are based on actual counts

 

Besides this really impressive flow of the shearwaters, the highlights in November were our first (ever!) Leach’s Storm Petrels (Océanite cul-blanc), the good number of Great Shearwaters of course – confirming that quite a few pass through Senegalese waters at this time of the year – a fine Balearic Shearwater (Nov. 18; Puffin des Baléares), and an imm. Red-footed Booby seen twice flying past the Calao (Fou à pieds rouges). Another big surprise and clearly one of my highlights was a huge Killer Whale (Orque) swimming past at mid-range, apparently heading SW – not my first here at Ngor, but this one was really impressive, nicely showing its massive dorsal fin.

November summary:

Species

2019

2018

2017

Cory’s/Scopoli’s Shearwater 56,438 18,593 30,836
Great Shearwater 125 32 0
Sooty Shearwater 1,174 573 526
Balearic Shearwater 1 0 0
Manx Shearwater 5 4 1
Shearwater sp. 16 31 2
European Storm-Petrel 0 0 1
Leach’s Storm-Petrel 3 0 0
Storm-Petrel sp. 10 0 0
Northern Gannet 3,896 1,239 60
Brown Booby 0 2 3
Red-footed Booby 1 1 0
Oystercatcher 0 0 2
Common Ringed Plover 0 0 1
Grey Plover 1 0 0
Whimbrel 9 4 0
Bar-tailed Godwit 5 0 0
Grey Phalarope 1 0 26
Audouin’s Gull 255 514 40
Lesser Black-backed Gull 37 2 17
Yellow-legged Gull 3 0 0
Large gull sp. 47 0 5
Slender-billed Gull 10 1 1
Sabine’s Gull 144 13 226
Arctic/Common Tern 1,272 836 764
Little Tern 14 14 1
Sandwich Tern 313 105 178
Lesser Crested Tern 2 7 18
African Royal Tern 19 9 2
Caspian Tern 3 1 2
Black Tern 29 3 321
Catharacta Skua sp. 32 23 5
Pomarine Skua 2,917 2,144 1,819
Arctic Skua 149 66 76
Long-tailed Skua 1 1 9
Skua sp. 149 60 313
Total birds 63,833 21,984 33,033
Total days 12 21 20
Number of hours 33h 30h30′ 28h

 

November 11th clearly was one of our most memorable Seawatch sessions ever: in just 3 hours, we counted an impressive 12,492 birds belonging to 23 species, a remarkable diversity at this time of the year: check out our eBird checklist here!

Once again, needless to say that Dakar clearly ranks as one of the top seawatch spots in the world!

 

 

Seawatching Ngor – September 2019

I count myself extremely lucky to live just a few minutes away from what must surely be one of the best seawatch sites in the world. What other capital can compete with Dakar on that front? It does make it hard not to go out there every day, especially at this time of the year when so many migrants can be seen from this privileged spot. And I’m fortunate to have a very flexible work schedule that allows me to spend an hour or so counting seabirds before heading to the office! I’m obviously spending too much time at the Calao at the moment… but then again it’s always better being out birding in the field than sitting behind a desk (especially when The Field is a comfortable terrace, sat under a sun umbrella with a cup of decent coffee).

Anyway, time for the September numbers:

  • 25 days
  • 38 hours
  • 20,109 birds belonging to 36 species counted (total so far: 27,303 birds!)

This is a much better coverage than in previous years, and as a result the number of birds counted is higher for most species; Lesser Crested Tern is the main exception due to a later than usual passage, which only started properly at the very end of the month, picking up rapidly during the first few days of October (Sterne voyageuse).

As usual, here some of the highlights: good numbers of Manx Shearwater (also two possible Balearics… unfortunately too distant and poorly seen), and several Macaronesian Shearwaters including at least one that seemed right for Boyd’s (Puffins des Anglais et de Macaronésie). Sooty Shearwater passage was clearly more intense, or at least more visible, than last year, probably because of more favourable winds (Puffin fuligineux).

Numerous terns were counted of course, with the four most common species – Common & Arctic, Sandwich, Black Terns – accounting for nearly 90% of the twenty thousand birds counted this month (Sternes pierregarin et arctique, caugeks, Guifette noire). Roseates continued to pass through almost daily, up to 12 BPH (that’s birds per hour!), and so did Little Tern: with 304 birds in September, far more were seen than in previous years (and the passage continues: on 5.10 a total of 31 birds were seen in one hour, including a flock of 22) (Sternes de Dougall et naine). A Bridled Tern on the 4th is so far the only one of the season (Sterne bridée).

sandwichtern_ngor_20160925_img_5344_edited

Sandwich Tern / Sterne caugek, Ngor, Oct. 2016

 

September is also peak month for Sandwich Tern (Sterne caugek), which passes through daily in double or even triple digits (that’s BPH). The peak at the end of the month is clearly visible on this chart combining 2017 and 2018 data:

SandwichTern-Ngor_2017-18_chart

Hourly average number of Sandwich Terns per decad, 2017 & 2018

 

Now for some slightly more advanced data viz’ fun: I tried to find a clever way of visualising the intensity of bird migration at Ngor alongside wind speed and wind direction. The chart below shows average “BPH” per day as histograms (primary axis: number of birds) and wind speed as the dotted line (secondary axis: knots), while the colour represents the wind direction: dark green for WNW to N winds, pale green for SW to W winds, and orange for SSW to ENE. One would expect the highest number of birds during the favourable winds, i.e. higher wind speed from a WNW to N direction, and less so on days with little wind and/or with winds coming from the “wrong” side. That does seem to be the case on most days, but not always… though in general it’s fair to say that days with stronger NW winds usually see the highest number of birds, and also a higher diversity of species. Shearwaters, skuas, Sabine’s Gulls and most terns are largely influenced by these conditions, which can rapidly change from day to day or even within the same day. A good site to check out wind forecasts is Windguru.

BPH-Wind_Chart_September2019.JPG

Disclaimer: nothing scientific here, just fooling around with Excel!

 

Arctic Skuas continued to pass through on a daily basis, and Long-tailed Skuas were seen on 13 dates, mainly at the start and at the end of the month, with a max. of 61 birds in 2h15′ on the 4th (Labbes arctique et à longue queue). The four Catharacta skuas were seen in the last week of the month but as usual could not be identified down to species level (Great or South Polar Skua, Grand Labbe/Labbe de McCormick).

A usual, waders were fairly well represented this month: Whimbrel and Oystercatcher remain the most frequent migrants and thanks to the regular rains this autumn there has been a good diversity of waders in general, including my first Grey Plovers here and regular sightings of migrating Turnstones (Courlis corlieu, Huîtrier pie, Pluvier argenté, Tournepierre). Red Phalaropes were seen on five occasions in relatively modest numbers (Phalarope à bec large).

Oystercatcher_Ngor_20170930_IMG_4931

Oystercatcher / Huîtrier pie, Ngor, Oct. 2017

 

Table with September totals for 2019, 2018 and 2017:

Species

2019

2018

2017

Cory’s/Scopoli’s Shearwater 2 0 0
Sooty Shearwater 271 87 393
Balearic Shearwater 0 0 1
Manx Shearwater 98 6 60
Boyd’s/Barolo Shearwater 9 16 1
Shearwater sp. 51 22 34
Storm-Petrel sp. 1 0 0
Northern Gannet 0 1 1
Brown Booby 0 4 3
Oystercatcher 51 20 16
Whimbrel 211 75 78
Eurasian Curlew 0 0 2
Bar-tailed Godwit 4 1 8
Grey Plover 2 0 0
Common Ringed Plover 0 2 0
Turnstone 33 2 0
Dunlin 0 0 40
Sanderling 12 0 25
Little Stint 1 0 0
Common Sandpiper 1 0 0
Greenshank 1 0 0
Common Redshank 3 1 1
Grey (Red) Phalarope 163 133 1
Audouin’s Gull 21 1 3
Lesser Black-backed Gull 1 15 1
Kelp Gull 1 0 0
Large gull sp. 1 5 0
Slender-billed Gull 6 1 1
Grey-headed Gull 0 1 2
Sabine’s Gull 95 43 123
Arctic/Common Tern 11,161 4,100 4,500
Roseate Tern 144 89 35
Little Tern 304 57 76
Sandwich Tern 2,425 2,080 1,928
Lesser Crested Tern 61 147 95
African Royal Tern 295 305 219
Caspian Tern 10 13 19
Black Tern 3,870 2,187 2,342
Sooty Tern 0 1 0
Bridled Tern 1 0 0
Great/South Polar Skua 4 1 2
Pomarine Skua 13 5 35
Arctic Skua 400 172 142
Long-tailed Skua 215 265 59
Skua sp. 167 64 226
Total birds 20,109 9,922 10,472
Number of days 25 17 15
Number of hours 38h35′ 24h50′ 20h30′

 

In addition to the seabirds, as usual a few other species were noted on active migration: a Purple Heron on 10.9 and more surprisingly two Squacco Herons the next day coming from out at sea. Common Swifts were spotted on at least three occasions (max. 66 on 11.09, migrating low over the ocean), while a Hoopoe was seen on 8.9 and a Sand Martin on 12.9 (Heron pourpré, Crabier, Martinet noir, Huppe fasciée, Hirondelle de rivage). What appeared to be a juv. Barbary Falcon was seen several times from 4 – 12 Sept., with a Peregrine also here on 9th (Faucons de Barbarie et Pèlerin). This provided for some action as both birds were regularly seen hunting pigeons and other birds; on the 6th it was a juv. Common Cuckoo (or at least I assumed it to be this species and not African Cuckoo) which was seen coming on land from Ngor island or islet, chased by the Barbary Falcon only to disappear into the Calao gardens and never to be found again… (Coucou gris).

PurpleHeron_Ngor_20170924_IMG_4800

Migrating Purple Heron / Héron pourpré en migration, Ngor, Sept. 2017

 

That’s all for now – let’s see what October brings (Pomarine Skuas! Sooty Shearwaters! Sabine’s Gulls!). Conditions are expected to be good in the next few days.

The August report can be found in this post.

 

 

 

Seawatching Ngor – August 2019

An update on this autumn’s seabird migration at Ngor is long overdue, so here we set off the season’s summary with the month of August. I managed to count migrants during 18 hours spread out over 16 sessions, starting with the first on August 9th, straight after coming back to Dakar from a short break Up North. As usual I tried to do relatively brief sessions (usually about an hour) as often as possible, typically early morning about an hour after sunrise. And always from the Club Calao terrace, of course.

Calao_20190831_IMG_4524

View from the Calao terrace, 31 August 2019

 

With some 7,100 birds counted, numbers passing through during August were about average in comparison with previous years. The few highlights so far were a Great Shearwater (Puffin majeur) flying SW on the 10th which I believe is the first August record, more than usual ‘Macaronesian’ Shearwaters (=Boyd’s or Barolo, Puffin “de Macaronésie”) with no less than 21 birds spread out fairly evenly throughout the period, and again a decent amount of Long-tailed Skuas (Labbe à longue queue). So far, 226 of these elegant pelagic skuas passed through, compared to 213 in August 2018; last year a record 500 were logged during the entire season. Top day was the 20th when I counted a very honorable 84 birds in just one hour, surprisingly during modest NNW wind – always impressive seeing loose flocks of up to 15-20 birds, usually including several adults. None were seen the following two days but during 24-26th there were 89 in 4h35′. Last year the peak passage was during the first decad of September when no less than 217 were counted in just 75′ on 2.9.18, so it’s possible that quite a few more Long-tails will pass through in coming weeks, though this will in part depend on wind conditions: moderate to strong winds from W to NW are usually required to see this species in double or even triple digits (in 2017, hardly any were seen, as shown in the chart below where the dashed line is 2017 and the dotted line 2018; solid line is hourly average per decad).

LTS_Ngor_Chart2017-18

 

Other pelagics included early Sooty Shearwaters (Puffin fuligineux) with seven birds during 24-26 August, and three Sabine’s Gulls (Mouette de Sabine) on the 20th. September and October should see many more of these two species! In contrast with last year when more than a thousand birds were seen in August when conditions were good for this species, just three Red Phalaropes (Phalarope à bec large) were detected this past month, though I had the first small flock this morning Sept. 1st, about 15 towards the SW and one coming in from the N and landing at sea. Of course many must have passed through these past few weeks, just too far off-shore for them to be seen from the coast.

Red Phalarope - DSC_2276 - B Mast

Typical view of a migrating Red Phalarope, low over the waves… Off Ngor, Oct. 2018 (Bruce Mast)

 

What was most likely the same Red-footed Booby (Fou à pieds rouges) was seen daily from 9th-12th, usually flying past at close range and sometimes feeding just behind the surf, with two birds together on Aug. 17th. I also twice saw one in July so it’s quite possible that at least one of these two immatures – both dark morph, as all others seen so far – oversummered around the peninsula.

As usual, the most frequently seen wader was Whimbrel, with just a handful of Oystercatchers and Bar-tailed Godwits each (Courlis corlieu, Huîtrier pie, Barge rousse). The lower number of waders compared to the past few years is probably due to the late arrival of the rains and a four-day gap in my presence during the last week of the month (waders tend to be seen mostly during and just after spells of rain here).

Whimbrel_Ngor_20170930_IMG_4932

Whimbrel / Courlis corlieu, Ngor, Oct. 2017 (BP)

 

The table below lists all species with totals for the month, with 2017 and 2018 numbers to compare with. Note that the vast majority of the ‘Comic’ Terns were Arctic, and the higher number of Roseate Terns is possibly explained by the fact that I may feel more confident identifying these birds (Sterne arctique/pierregarin, Sterne de Dougall). Oftentimes, Roseates are migrating 2-3 birds together, usually mixed in with Arctic Terns.

 

Species

2019

2018

2017

Wilson’s Storm-Petrel 0 157 0
Cape Verde Shearwater 0 100 1
Great Shearwater 1 0 0
Sooty Shearwater 7 0 0
Boyd’s/Barolo Shearwater 21 3 0
Shearwater sp. 3 6 4
Red-footed Booby 2 0 0
Oystercatcher 8 8 6
Whimbrel 127 340 437
Bar-tailed Godwit 6 1 49
Turnstone 0 4 13
Red Knot 0 28 0
Ruff 0 1 5
Sanderling 0 0 16
Curlew Sandpiper 0 0 4
Little Stint 0 0 4
Grey (Red) Phalarope 3 1,123 0
Common Sandpiper 0 7 1
Common Redshank 1 1 1
Audouin’s Gull 7 0 0
Lesser Black-backed Gull 0 0 1
Yellow-legged Gull 0 1 0
Large gull sp. (prob. Kelp Gull) 1 0 2
Slender-billed Gull 1 0 1
Sabine’s Gull 3 12 6
Arctic/Common Tern 3,878 4,500 1,399
Roseate Tern 56 44 10
Little Tern 23 56 28
Sandwich Tern 462 343 463
Lesser Crested Tern 4 40 41
African Royal Tern 342 585 166
Caspian Tern 10 14 1
White-winged Tern 0 1 0
Black Tern 1,803 2,160 774
Bridled Tern 0 4 0
Catharacta Skua sp. 0 0 1
Pomarine Skua 3 1 2
Arctic Skua 59 94 24
Long-tailed Skua 226 213 25
Skua sp. 46 18 17
Total birds 7,103 9,865 3,502
Number of days 16 22 13
Number of hours 18h05′ 26h20′ 17h05′

 

Meanwhile at Technopole, the lagoons are finally starting to fill up again now that we’ve had a few decent showers, though a lot more will be needed to ensure that the site remains wet all through the dry season. There’s a good diversity of waders again and breeding activity is at its peak for many of the local species. Striated Heron for instance is now very visible, and last Sunday I saw a pair feeding a recently fledged young at the base of one of the Avicennia stands on the main lagoon, while Spur-winged Lapwing juveniles are all about, Zitting Cisticolas are busy tending their nest, and this morning a small flock of juvenile Bronze Mannikins was seen (Héron strié, Vanneau éperonné, Cisticole des joncs, Capucin nonnette).

Several wader species are starting to pass through again, such as Common Ringed Plover, Little Stint, Curlew Sandpiper and Marsh Sandpiper (Grand Gravelot, Bécasseau minute, Bécasseau cocorli, Chevalier stagnatile). It’s also peak season for Ruff, with a very modest max. so far of 148 counted this morning (Combattant varié).

On the gulls & terns front, a Mediterranean Gull was still around on 18 & 25.8, probably one of the two immatures that were seen in May-July and apparently completing its summer stay here (these are the first summer records for the species in Senegal), while the first juvenile Audouin’s Gulls of the year were also seen last Sunday, Aug. 25th (Mouette mélanocéphale, Goéland d’Audouin, . This morning a White-winged Tern was of note, as were 24 Little Terns resting with the other terns or feeding above the main lake (Guifette leucoptère, Sterne naine). Three Orange-breasted Waxbills and three Long-tailed Nightjars on 11.08 were far less expected (Bengali zebré, Engoulevent à longue queue).

This morning’s eBird checklist has all the details.

 

CommonRedshank-Ruff_Technopole_20190901_IMG_4541

Redshank & Ruff / Chevalier gambette & Combattant

CurlewSandpiper_Technopole_20190901_IMG_4560

Curlew Sandpiper / Bécasseau cocorli juv.

 

 

 

American Golden Plover at Palmarin

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.

More on the identification and on the occurrence of the species in Senegal in this post from last November and also here.

AmericanGoldenPlover_Palmarin_20190415_IMG_2908

American Golden Plover / Pluvier bronzé

AmericanGoldenPlover_Palmarin_20190415_IMG_2913

American Golden Plover / Pluvier bronzé

AmericanGoldenPlover_Palmarin_20190415_IMG_2919

American Golden Plover / Pluvier bronzé

AmericanGoldenPlover_Palmarin_20190415_IMG_2922

 

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.

Palmarin_20190414_IMG_2798

 

Below are a few pictures of other species seen during the 24 hours we spent at Palmarin.

BlackwingedKite_Palmarin_20190415_IMG_2893

Black-winged Kite / Elanion blanc

 

BrucesGreenPigeon_Palmarin_20190415_IMG_2881

Bruce’s Green Pigeon /  Colombar waalia

 

SlenderbilledGull_Palmarin_20190414_IMG_2838

Slender-billed Gull / Goéland railleur

 

YellowbilledOxpecker_Palmarin_20190415_IMG_2901

Spot the Yellow-billed Oxpecker hitching a ride (Piqueboeuf à bec jaune) (J. Piot)

 

Palmarin_20190414_IMG_2796

Unsuccessful attempt at reading a Caspian Tern with yellow ring (in any case a local bird) (J. Piot)

 

Let’s see if this spring any American Golden Plovers turn up at Technopole again…

 

 

Iberian Chiffchaff in West Africa

We’re continuing our little series on the status of some lesser known passerines that spend the winter in Senegal. This time round we’re looking at Iberian Chiffchaff (Pouillot ibérique), yet another drab songbird that can be tricky to identify unless of course it’s singing. We won’t go much into its identification in this post; a lot has been written on the topic, though unfortunately the standard West Africa field guides lack sufficient detail and may oversimplify the matter somewhat. In addition, few if any of the local guides really know how to identify the species in the field, and not all visiting birders pay much attention to these LBJs.

There are a few subtle differences in plumage, but generally it’s not easy to identify these birds on plumage and “jizz” alone..  so maybe it’s useful after all to summarise key characteristics here. Lars Svensson, in what is still one of the main reference papers on Iberian Chiffchaff identification (2001), neatly listed the following field characters in comparison with Common Chiffchaff:

  1. As a rule, the entire upperparts of ibericus are purer moss green than on Common Chiffchaff, lacking the brown tinge on crown and mantle usually present in collybita in freshly moulted plumage in early autumn a very slight brownish tinge can be found on the greenish upperparts of some Iberian Chiffchaffs
  2. More tinged yellowish-green on sides of head and neck, and has no buff or brown hues at all, or only very little of it behind the eye and on ear-coverts. The breast is whitish with clear yellow streaking
  3. Typically, has vivid lemon yellow undertail-coverts, contrasting with a rather whitish centre to the belly
  4. Supercilium on average more pronounced and more vividly yellow, particularly in front of and above the eye
  5. On average, the legs are a trifle paler brown on Iberian than on Common Chiffchaff, though many are alike
  6. Bill is very slightly stronger [though I find this one of very little use in the field!]
IberianChiffchaff_Gandiol_IMG_2750_edited

Iberian Chiffchaf / Pouillot ibérique, Gandiol, 31 March 2016 (BP). Note yellowish supercilium, undertail and flank streaks, dull greenish upperparts, pale brown legs, whitish belly, and apparently also pale bill base

 

Clearly these are mostly subtle differences and when identifying on plumage alone, a combination of characters should typically be used. Confusion with Willow Warbler is not unlikely, even by experienced birders, and I’m assuming that at least some Iberians are noted as Willow Warbler, especially in mid-winter in northern Senegal when Willow Warbler should in fact be rare, as it winters chiefly in the forest zone further south. The longer wings, pale underparts and paler legs can indeed result in striking similarities between Willow and Iberian. A good pointer to separate these two is that the latter typically dips its tail while feeding, whereas Willow, Warbler characteristically flicks its wings while moving its tail sideways.

The two pictures below were taken by Frédéric Bacuez near Saint-Louis, on 18.4.16 (top) and 20.1.13 (bottom), and while it’s probably impossible to be certain, I do tend to believe these are Iberian Chiffchaffs.

 

Bango, April 2016 (© F. Bacuez)

2013 01 20 9h30. Pouillot fitis apr_s le bain, dans l'eucalyptus. Photo par Fr_d_ric Bacuez, IMG_9104 (2)

Iberian Chiffchaff or Willow Warbler? I tend to think it’s an ibericus (© F. Bacuez)

 

The vocalisations on the other hand are far more reliable and are indeed always ideal in order to confirm an Iberian Chiffchaff, particulary the song. While there’s some variation and there may be some “mixed singers”, the difference with Common Chiffchaff is usually obvious (though maybe a bit less so on this one from Wassadou). It’s worthwhile pointing out though that besides the quite distinctive song, a good yet undervalued criterion is the call of the species – see this nice summary on the Turnstones blog (and also Collinson & Melling 2008, who state that the call “in sharp contrast to that of Common Chiffchaff, is downwardly inflected, from 5 to 3 kHz, transcribed as ‘piu’ or ‘peeoo’, perhaps reminiscent of the call of Siskin” – now compare with my recording from Technopole (same bird as in the song recording): I wouldn’t say this sounds like a Siskin – and even less like a Bullfinch! – and at 3.5-6 kHz the frequency is clearly a bit higher as can be seen on the sonogram below (click to enlarge).

IberianChiffchaff_Technopole_20173112_call_sonogram_XC397677

 

 

Status & Distribution in Senegal

Up to not so long ago, most authors considered Iberian Chiffchaff to be a resident or partial migrant, mostly due to lack of reliable identification criteria at the time. Svensson (again!) provided the most comprehensive overview of our knowledge of the wintering areas in his 2001 paper, concluding that it is “a long-distance migrant which winters primarily in tropical Africa“. This assumption was however based on very few specimens and even fewer reliable field observations. One of these is of a bird “singing like an Iberian Chiffchaff” by Yves Thonnerieux from northern Ghana, and the only two specimens from wintering grounds are from Mali in 1932 (Segou) and 1955 (Bamako); both were found by Svensson in the museum of natural history in Paris (MNHN). A third specimen was collected in January 1955 in Tunisia, suggesting that some birds may winter north of the Sahara; Svensson also showed that the species is present during spring migration in Morocco (at least late March – early April).

With increased “observer awareness” and better reporting systems, recent years have seen a clear increase in field observations from West Africa, described further below. Combined with the absence of any winter records from the Iberian peninsula, I think it’s quite well established now that indeed most if not all Iberian Chiffchaffs winter south of the Sahara.

To further refine its status in West Africa, we turn to our usual suspects: Morel & Morel  provide a single record, presumably obtained by themselves, of a singing bird at Richard Toll on 22-24.2.87 (this is probably the unpublished record “from tropical Africa” that Svensson refers to). This can safely be assumed to be the first published record for Senegal; identification was apparently largely based on song since they write that they compared the song with recordings by Claude Chappuis. It’s quite easy to miss out on this observation though, as ibericus (or brehmi as it used to be known) is only referred to in the annex of Les Oiseaux de Sénégambie (1990), as their sighting was obviously too recent to be included in the near-final manuscript of their book. Of course, the species was at the time still considered to be “just” a subspecies of Common Chiffchaff. Rather curiously, the Morels refer to a significant proportion of Scandinavian Common Chiffchaffs (ssp. abietinus) – up to half! – though we now know that these populations tend to winter in eastern Africa, heading in a south-easterly direction in autumn. Could it be that these were actually Iberian Chiffchaff rather than abietinus?

Moving on, Rodwell and colleagues (1996) refer to three records of calling (singing?) birds in the Djoudj NP in Jan 1990, Jan 1991 and Feb 1992. Sauvage & Rodwell (1998) do not provide any additional records: up to the mid-nineties, ibericus was obviously still considered a rare to scarce winter visitor to northern Senegal. More than a decade later, Borrow & Demey still consider the species’ distribution in Senegal as “inadequately known”, and their map only shows the lower Senegal valley.

As is the case with quite a few other little known taxa that were recently elevated to species rank – think Moltoni’s Warbler, Seebohm’s Wheatear, Atlas Flycatcher – these past few years our knowledge has greatly increased, and it is clear that Iberian Chiffchaff is indeed quite frequent in northern Senegal. Recent reports mainly come from the Djoudj NP – obviously a key wintering site, with decent densities – and from around Richard Toll and Saint-Louis (e.g. Bango, Trois-Marigots, Langue de Barbarie, and see picture above). There are however a number of recent records elsewhere that suggest that the species is more widespread: last winter I was lucky to find a singing bird at Technopole which is thought to be the first record from Dakar; there are also a few reports from the Somone lagoon, though not sure that these are reliable (I have suspected the species here before, but never been able to confirm based on call or song). Rather intriguingly, the species was also seen several times along the Gambia river at Wassadou these past two years: first in December 2017, then more than two months later at least one singing bird that we found on 24.2.18, and again this winter (7.1.19). Finally, another singing bird was reported near Kounkane, Velingara, on 28.1.18 (G. Monchaux) – to our knowledge the first record from Casamance. The observations in these southern locations suggest that the species is more widespread and that it can turn up anywhere in Senegal.

In Mauritania, it appears that up to recently the only records were obtained during extensive field work conducted by the Swiss Ornithological Station, with several birds captured both in spring and in autumn 2003 (Isenmann et al. 2010). There are several more recent reports from around Nouakchott mainly, presumably of birds passing through. In addition to the two aforementioned specimens from Mali, the only other record from that country that I’m aware of is of a singing bird that I recorded in a hotel garden in Bamako, where it was singing for at least a week in January 2016. Burkina Faso should also be part of the regular range, though there again there are just a couple of records, most recently a singing bird reported by van den Bergh from the Bängr-Weeogo park in Ouagadougou in December 2011.

The Xeno-canto range map, which is largely based on BirdLife data, is probably the most accurate when it comes to the winter range (though not for the breeding range, the species being absent from most of central and eastern Spain). It should also include all of northern Senegal, or at a minimum, the lower and middle river valley, particularly the Djoudj NP which is omitted from the map below. I’m not sure that the species has been reliably recorded from Gambia even though there are several unverified observations on eBird. Further north, there are several winter records from Western Sahara between early December and early February, mainly at coastal sites (Bergier et al. 2017), suggesting that not all Iberian Chiffchaffs cross the Sahara. Spring migration is noted from mid-February to mid- or end of April.

IberianChiffMap_XC

 

Iberian Chiffchaff should be present in Senegal and generally throughout its winter quarters from about October to early or mid-April; the earliest observation I could find is one of a bird reported singing east of Richard Toll on 27.10.15. A Danish group reported two birds in Djoudj in early November 2017, but other than that almost all records are from December – February during the peak orni-tourist season.

Paulo Catry and colleagues (including our friends Miguel and Antonio!) showed marked differential distance migration of sexes in chiffchaffs, with females moving further south than males. Their study did not distinguish between Common and Iberian Chiffchaff, but because south of the Sahara (Djoudj mainly), sex-ratios were more male-biased than predicted by a simple latitude model, their findings suggest that among the chiffchaffs wintering in West Africa, a large proportion is composed of Iberian birds, providing further support that these birds are long distance migrants. The ringing data from Djoudj also showed that chiffchaffs display differential timing of spring migration, with males leaving the winter quarters considerably earlier than females [typically, male migrant songbirds arrive a little earlier on the breeding grounds than females, presumably so they can hold and defend a territory by the time the females arrive].

Finishing off with some essential ibericus reading…

 

 

 

 

Status & Distribution of Seebohm’s Wheatear in Senegal

This is the second part of a review of what we know about Seebohm’s Wheatear in Senegal, the first part covering its identification in autumn and winter. As already mentioned in that piece, this species has a pretty restricted range, breeding only in the Middle and High Atlas of Morocco and Algeria, generally above 1500 meters asl. Until fairly recently it was considered more of an altitudinal or short-range migrant, but it’s clear now that it’s actually a medium-range “total” migrant (i.e. all populations tend to migrate away from breeding grounds – not surprising given that much of it is covered in snow during winter!).

2018 04 24, 18h07. IMG_5216+ - small

Seebohm’s Wheatear / Traquet de Seebohm m. ad. on breeding grounds at Oukaimeden (Morocco), April 2018 (© F. Bacuez)

 

The non-breeding range of “Black-throated Wheatear” is given by the Handbook of the Birds of the World Alive as “West Africa (mainly SW Mauritania and Senegal to W Mali, occasionally in S Morocco)”. However, the HBW range map is rather incorrect: all regions of Senegal and Gambia and even Guinea-Bissau are included, although as far as I know the species has never been reported from the latter two countries. The same applies to Guinea and Burkina Faso which are also partly included in the range. Let’s hope that this will get corrected soon – the HBW species page of this newly recognised taxon (formerly considered a subspecies of Northern Wheatear) was only fairly recently published online, and is obviously work in progress.

The winter distribution in Shirhai & Svensson (2018) on the other hand seems more accurate, though perhaps a bit too conservative in that it includes only a very small part of western Mali. Judging by the data available on the Biodiversité Al-Maghrib portal, it’s clear that some birds winter may further to the north, much closer to the breeding grounds. Indeed, there are several observations from southern Morocco and from the Western Sahara from December-February, and it’s easy to imagine that it’s rather beneficial for these birds if they can avoid crossing the Sahara. There are also a few recent records from the Adrar region in Mauritania, e.g. this one and this one by Wim van Zwieten and friends seen at the end of December last year, suggesting that this area may also be part of the species’ winter range.

The Shirihai & Svensson map is most likely largely based on a paper on Seebohm’s Wheatear in West Africa by Förschler and colleagues (2008), which to date gives the most comprehensive overview of our knowledge of its wintering grounds in the Sahel, following field work they undertook in western Niger, Mali and Mauritania combined with a review of published data. They note that “although seebohmi was previously thought to be a resident or only a partial migrant by some authors, it is now considered a true migrant, with the majority of the population leaving Morocco and Algeria in winter. Browne (1982) found a major wintering area, roughly estimated to hold at least 50,000 individuals, in the eastern part of south-west Mauritania […].” They also refer to three more southern records from Djoudj NP (mentioned by Rodwell et al. 1996), and conclude that “the majority of this taxon’s population appears to winter immediately south of the Sahara, in the Sahel zone of southern Mauritania, northern Senegal and north-west Mali between 15–18°N and 09–16°W, although its wintering grounds may range even further east, including parts of central Mali.

SeebohmsWheatear_Adrar_Dec2018_WimvanZwieten

Seebhm’s Wheatear / Traquet de Seebohm, Atar 30 Dec 2018 (W. van Zwieten)

 

Away from its regular range, there are a few scattered records of Seebohm’s Wheatear in the Mediterranean and one from the Netherlands (April 2017), plus a couple of possible sightings from the UK: Italy (one in April 2014 in Sardinia), Gibraltar, Malta, Tunisia, and several times in the Libyan desert and even once from western Egypt. It’s also on the list of the Canary Islands, and apparently also reported from Cameroon, as per Arnoud B. van den Berg on DutchAvifauna,nl). So it’s definitely a species to have on one’s radar when encountering an unusual wheatear in western and southern Europe; I can imagine that one day a fine male will show up in spring in the Camargue, the Spanish coast or on the Balearic islands – or pretty much anywhere north of its range for that matter.

 

Status & Distribution in Senegal

In Senegal, in addition to the aforementioned Djoudj records, the species has been reported from the Richard-Toll, Dagana, Podor and Ndioum areas, and at least once from the lower Senegal valley, on 2.3.09 by Frédéric Bacuez, Ornithondar. Of course, Frédéric had already provided a comprehensive overview of the distribution of Seebohm’s Wheatear in Senegal, more precisely in this blog piece from 2016. The Morels mention several spring records (13 March – 14 April) in the middle Senegal valley as far upstream as Salde, plus one from early January 1981 near Richard-Toll seen by Alan Tye. They also report the presence on two occasions some 60 km south-east of Richard-Toll. But that’s about it: not an awful lot of records to go by! It’s quite possible that it may also be found at least occasionally in the Ndiael reserve, around lac de Guiers and into the Ferlo (e.g. Six Forages). These sites are not very often visited by birders or ornithologists, and the recent records that I came across are typically from Richard-Toll and the Podor areas, with the exception of a first-winter male at Saot (ENE of Touba), seen by J-F Blanc in January 2010. No records are known from the Grande Côte, though it’s not impossible of course that the species shows up here at least from time to time.

As can be seen from the map below, northern Senegal is on the southern edge of the species’ winter range, which may explain why most birds seen here appear to be first-winter birds. Adults, and in particularly males, may well winter further north including on the other side of the Sahara as mentioned earlier. Though it’s certainly not rare, the species seems to be nowhere common across its range in Senegal. When we toured the middle valley in January last year, we saw the species in small numbers (1-2 ind. per site) at three different locations: Bokhol, in a sparsely wooded dune depression east of Ndiayene Pendao, and at Gamadji Sare. Some sites such as the Bokhol “fores” appear to be pretty reliable, and a dedicated search would probably reveal other sites where they may be regular and maybe even locally common; in 1973 Seebohm’s Wheatear  was said to be “the most common [wheatear] species in winter in the Podor region”, while Sauvage & Rodwell refer to a total of 18 ind. seen at three locations in February 1993 in the Podor atlas square. There may of course be annual variations, possibly depending on any cold spells in north-west Africa, but obviously more data are needed (as usual!).

The majority of sightings are made between December and early March, but this is when most birders visit the country and it’s likely that Seebohm’s is regularly present at least from (mid?) October and up to early April. In Nouakchott, it’s been seen as early as the end of September (see Rob Tovey’s eBird checklist with two pictures of a fresh autumn male), but when I last visited the Podor region in early October 2018 I did not see any birds on the sites that held several wintering individuals back in January, so it seemed that they had not arrived yet at that time.

SeebohmsWheatear_Bokhol_20180105_IMG_8145

Seebohm’s Wheatear / Traquet de Seebohm 1st winter m. on wintering site in northern Senegal, Jan. 2018 (B. Piot)

 

In short, the main wintering area of Seebohm’s Wheatear lies in Mauritania, northern Senegal and NW Mali, on the edge of the Sahara and in the northern Sahel zone. It is a regular winter visitor to northern Senegal, being scarce locally fairly common along the middle Senegal Valley, from October/November to March or early April.

The main winter range in West Africa should look something like this, though it possibly extends a bit further south in Senegal and further east along the Mauritania-Mali border. And as mentioned already, some birds may winter in southern Morocco and in the adjacent Adrar region of Mauritania, as well as along the coast north of Nouakchott: the below map may well need to be adjusted as such – comment welcome, as usual.

SeebohmsWheatear_Range

Approximate extent of main winter range of Seebohm’s Wheatear / Etendue approximative de l’aire d’hivernage du Traquet de Seebohm

 

Habitat

While its habitat in summer essentially corresponds to Alpine meadows with rocks and stone structures, usually devoid of any trees, in winter the species may inhabit light Sudano-Sahelian woodland, at least along the Senegal valley. Elsewhere, particularly further north in Mauritania, it probably occurs mostly in more open habitat. The Bokhol forest just east of Dagana seems to be a reliable place to find Seebohm’s Wheatear: it is comprised of a mix of Acacia, Balanites aegyptiaca and other trees growing on sandy soil with little or no undergrowth. Indeed, most of the winter range of the species is heavily overgrazed anyway, and away from the floodplains there is generally very little vegetation cover… the picture below gives an impression of the the sad state of what remains of northern Senegal’s “forests” – a very liberal concept here at these latitudes.

ForetdeBokhol_20180105_IMG_8156

Foret de Bokhol – typical lightly wooded habitat of Seebohm’s Wheatear in northern Senegal

 

We’ve also encountered the species on several occasions at Gamadji Sare, where part of the area is also made up of light woodland, not dissimilar to Bokhol, though less mature. Some birds here were seen in more open areas, including right by the bank of the Doué river where this picture was taken:

SeebohmsWheatear_GamadjiSare_20180106_IMG_8554

Seebohm’s Wheatear / Traquet de Seebohm f. (prob. first winter), Gamadji Sare, Jan. 2018 (B. Piot)

 

In much of its range, the species is cohabiting with Northern (ssp. oenanthe and probably also libanotica), ‘Greenland’ (leucorhoa) and Isabelline Wheatear, probably locally also with Black-eared and Desert Wheatears though the latter two species are typically very scarce in Senegal it seems. Heuglin’s Wheatear is also possible in winter in northern Senegal, but it’s much rarer and was added to the national list only recently, following a record in the Djoudj NP in January 2007 (and was found breeding even more recently in the Kédougou region).

 

A brief etymology¹ of Seebohm’s Wheatear

SeebohmsWheatear_Mayaud_1951

Noël Mayaud’s illustrations of Oenanthe oenanthe seebohmi (1951!)

The HBW Alive lists this taxon as Black-throated Wheatear, another rather boring and unimaginative English name. I’ll stick to Seebohm’s. Alternatively, Atlas Wheatear would be a pretty good one as it nicely highlights the restricted breeding range of the species; this name is already in use in Spanish and German, and no doubt in other languages.

But actually, why Seebohm’s Wheatear? Tim Birkhead – author of (at least) two great books, The Wisdom of Birds and Bird Sensewrote about Henry (or should it be Harry?) Seebohm, a 19th century British industrial and ornithologist, most famous for his fieldwork in Siberia. Which doesn’t really explain why our wheatear from the Atlas goes by his name… enter Charles Dixon, who formally described the taxon in 1882 based on a specimen from the Algerian Atlas. A contemporary of Seebohm, Dixon collaborated on Henry Seebohm’s British Birds opus, so I think it’s safe to assume that Dixon named his newly described chat in honour of his friend. 

The term “wheatear” apparently comes from “white” and “arse”, referring to the prominent white rump found in most species.

 

¹ Etymology is the study of the origin of words and the way in which their meanings have changed throughout history. Applied to vernacular and scientific bird names, this comes down to retrieving the origins of these names.

 

Thanks once again to Frédéric Bacuez and Wim van Zwieten, and now also to Jérémy Calvo for making available some of their pictures from Mauritania and Morocco

SeebohmsWheatear - Oukaimeden - April 2018 - © Photo par Jérémy Calvo, DSC_8452-2 - small

Seebohm’s Wheatear / Traquet de Seebohm m. ad. on breeding grounds at Oukaimeden (Morocco), April 2018 (© J. Calvo)