Franklin’s Gull in Senegal & West Africa

A new observation of a Franklin’s Gull at Technopole, on May 20th, prompted me to have a closer look at the records of this American species in Senegal and more generally across West Africa. I’ve been compiling records of Nearctic vagrants for some time now, which I may use one day to write up a formal publication on the topic – the list currently includes 83 records of 18 different species and some patterns are starting to emerge.

No less than 21 of these records are of Franklin’s Gulls, though these correspond to at least 36 different observations (one record can refer to a bird seen over several dates). As such, this is by far the most frequent American vagrant seen in Senegal. It’s actually been annual at Technopole since 2011, year that saw the arrival of three different birds. In the following three years, at least five different birds were regularly seen, to the extent that Franklin’s Gull became an expected feature at Technopole during that period (I was lucky to see one of these birds in July 2012, during a visit with Paul). It’s been quite difficult to determine how many records there actually are, as it’s not always clear when multiple records relate to a single bird, and whether the recent spring sightings at Technopole (2015 – 2017) may also be all of just one returning adult.

Here’s the most recent bird:

Franklin’s Gull / Mouette de Franklin, Technopole, 20.5.18

This year’s bird is clearly not a returning adult, as it appears to be a second calendar year (“first summer”) bird. Ageing Franklin’s Gull is not always straightforward – see K. M. Olsen’s comment in this short post by Paul – but I think this bird can be fairly safely identified as a second year bird, based on the head pattern (adults such as last year’s should have a completely black hood) combined with a small amount of white in the primary tips – and note active moult of primaries.

Franklin’s Gull / Mouette de Franklin, Technopole 20.5.18

This is what we have in terms of records so far – corrections and additions welcome!

1. 29.5.83 Delta du Saloum, Fatick, paired with Grey-headed Gull, sitting on nest (Erard et al. 1984)
2. 17.1.86 Ile de Gorée, Dakar, first winter (F. Baillon) (Baillon & Dubois 1992)
3. 24.4.86 Delta du Saloum, Fatick, among Grey-headed Gulls (C. Devisse) (Baillon & Dubois 1992)
4. 3.12.88 Plage de Hann, Dakar, adult (J. J. Blanchon, P. J. Dubois, J. P. Pillion) (Baillon & Dubois 1992)
5. 18.2.91 Plage de Hann, Dakar, first winter (P. J. Dubois, P. Le Maréchal et al.) (Baillon & Dubois 1992)
6. 28.2.07 Saint-Louis, adult (J. Piette; H. Dufourny; ABC Recent Reports Vol. 14(2) & 15(1))
7. Oct. 2008 Ngor, Dakar (French seawatch team)
8. 26.1.11 Bao Bolon, Kaolack, 2nd year (R. Ottvall et al. – trip report here)
9. 24.7 – 1.8.11 Technopole, two 2nd year (P. Robinson)
10. 5.8.11 Technopole, 2nd year, different from previous two birds (P. Robinson)
11. 29.10.11 Yoff, Dakar (P. Robinson)
12. 11.2.12 Technopole (J.-F. Blanc, S. Cavaillès)
13. 3.5 – 18.8.12 Technopole, up to three seen min. nine times (P. Robinson, S. Cavaillès, BP)
14. 18.5.12 Almadies, Ngor, near lighthouse Pointe des Almadies, seen from boat (P. Robinson)
15. 16.4 – 4.8.13 Technopole, up to four seen min. eight times (P. Robinson et al.), also one on 18.8 at lac Mbeubeusse (P. Robinson, G. Citegetse et al.)
16. 6-16.3.14 Technopole, adult (P. Robinson; J.-F. Blanc)
17. 15-20.3.15 Technopole, adult (BP; J.-F. Blanc)
18. 3.5.15 Technopole, adult (BP) – possibly the same as in March, or a different bird (and treated as such in this list).
19. 13.7.16 Technopole, adult (W. Hagemeijer, M. van Leeuwen; photo on observado.org)
20. 14.5.17 Technopole, adult (BP)
21. 20.5, 10.6, 7.7, 22.8 & 20.9.18 Technopole, 2nd year (BP, M. Lecoq, G. Caucanas)¹

There’s obviously a clear increase in the number of records in the last eight years, even since 2007 after which this neat gull was not seen during two years only. The arrival of up to five different immature birds in 2011-2014 is noteworthy and as far as we know this was unprecedented in Africa. With the exception of this year’s bird, it’s quite possible that the single adults seen at Technopole since 2014 all refer to one or more of these original five, spending the winter further south and moving back north through Senegal in spring.

The near-absence of records prior to 2011 doesn’t mean much, since observer coverage was much lower then, so it’s hard to say anything much about longer term trends: the increase in records is probably in a large part related to increased observer pressure, particularly in Dakar where the majority of records are from. This also makes more sense, rather than that it reflects a real increase in records, considering that Franklin’s Gull is a species that’s said to be declining, particularly in the U.S.

Below is an attempt to plot the number of observations (not records!) and the number of birds involved, based on available data up to early June 2018.

Here’s one of the 2011 birds from Technopole, thought to be second year:

2nd c.y. (30.7.11, Paul Robinson)

This one is from barely a week later, and is thought to be an adult moulting into winter plumage:

ad.? (5.8.11, Paul Robinson)

And here’s the adult in full breeding plumage from May 2012 at sea off Almadies. Besides the all-dark hood, note the greater amount of white in the wing tips compared to immature birds:

Franklin’s Gull / Mouette de Franklin, Almadies, May 2012 (P. Robinson)

 

Trying to unravel any seasonal patterns is tricky with so few records, though in recent years it’s clear that most birds show up between March and August, with the most recent observations all from March, May and July. There are only a couple of October records, none from September and November, and at least since 2013 there’s no evidence of wintering birds (if there were any on the Dakar peninsula, we’d probably see them at least from time to time at Technopole!). On the chart below, I’ve included birds that were seen over multiple months in each of the months’ totals, hence the sum of records exceeding 21.

 

The breeding record from the Saloum delta is of course intriguing, and it’s not excluded that more attempts have occurred again since the 1983 record.

Franklin’s Gull outnumbering Slender-billed and Lesser Black-backed Gull on 23.7.13 at Technopole! (Paul Robinson)

 

Records from elsewhere in West Africa are much rarer than in Senegal: in Mauritania, one was seen on 27.1.06, followed by a second record on 17.4.16, both at Banc d’Arguin (Bull. African Bird Club 23: 238), then a third on 23.4.17 in Nouakchott (see Robert Tovey’s account on the find here). In The Gambia, Franklin’s Gull was seen in 1984, on 17.1.02, and again on 8-9.2 until 15.3.05 at least; all records are from Banjul. The first for Ghana was an adult on 8.5.11 on the Sakumono lagoon on the outskirts of Accra.

Nine records are known from Morocco, the most recent one being a first-winter bird on 12.2.16 at Oued Souss (Agadir) – so clearly not one of the Senegal birds as these were all adults by then.

Elsewhere in Sub-Saharan Africa, there are several records from South Africa, at least two from Mozambique, one from Congo-Brazzaville (one on 14.11.15 at the Kouilou-Niari River), at least one from Burundi, Uganda, Malawi, Namibia and Zambia, and the species is also listed as a vagrant to Ascension island and Tristan da Cunha. And the first for the Seychelles was seen on 7.5.17. They really do wander about!!

Franklin’s Gull – now known as Leucophaeus pipixcan –  is a widespread colonial breeder on the prairies of northern North America, wintering mainly in coastal regions on the Pacific coast of South America (Colombia – Chile; range map xeno-canto). It’s a regular vagrant to Europe, and stragglers have been recorded as far as Kazakhstan, Australia and New Zealand, even Antarctica.

 

¹ On 27.1.19, one bird (probably adult) was again at Technopole (BP, M. Lecoq)

 

A few references

Baillon, F. & P.J. Dubois, 1992. Nearctic gull species in Senegal and The Gambia. Dutch Birding 14:49-503

Érard, C, Guillou, J.-J. & Mayaud, N., 1984. Sur l’identité spécifique de certains laridés nicheurs au Sénégal. Alauda 52:184-188

www.allaboutbirds.org/guide/Franklins_Gull/lifehistory