A new species for Dakar (and Senegal!)

I didn’t think I’d ever write up a story on a bird that has always been one of the most common species around me, ever since I started looking at birds nearly 30 years ago… What’s more, it’s one of the most successful species ever, having spread across 4 continents in a remarkably short amount of time. Originating from southern Asia (it is said to have started spreading from the Indian subcontinent towards the north-west in the 1930s), it first conquered the Near East then all of Europe in a matter of a few years, and China in the other direction. North Africa was next, while a small introduced population in the Bahamas lead to the species taking over pretty much all of the US, in recent years spreading even into Canada and Central America, almost reaching South America… Its affinity with humans (they are rarely found more than a kilometer away from human settlements), high reproductive potential and ability to disperse and settle in new places, have allowed it to gradually conquer a great deal of the inhabited world.

So far, the Eurasian Collared-Dove had not reached Subsaharan Africa, but that milestone has obviously been achieved in recent years. Indeed, it turns out that there is a small population in Dakar which up to now had gone unnoticed. And it likely would have remained undetected a bit longer, had I not checked out Dakar’s very own “Central Park” recently. I’d only been once before to Parc de Hann on a short Sunday afternoon family visit, a few months ago, and last week decided to head out there again to see what was about in terms of bird life, and just to get some fresh air (well, sort of…) with Jane, on a rare day off while the boys were at school.

Towards the end of our tour of the park, we heard a familiar sound – a singing dove which very much recalled the Collared Doves back home in Europe. But we moved on, thinking it probably was a local species (Mourning or Red-eyed Dove) with a slightly unusual song, or to be honest, not really thinking much of it at the time. But later that day it got me thinking, and I double-checked songs of all regularly occurring Streptopelias in the region. None have such a distinctive slow, tri-syllabic song (sort of “ooh-HOOO – hoo”)… but then again, Eurasian Collared-Doves aren’t supposed to be around, so I couldn’t imagine finding the species this far away from the nearest known sites in Mauritania. Intrigued, I returned back to the spot on Saturday morning after a routine Technopole visit (Yellow-billed Stork! Yellow-legged Gull! Long-tailed Nightjar!), Parc de Hann being only a mere 10 minutes away from Dakar’s prime birding hotspot.

Within minutes of arriving, I heard the same sound again and this time was convinced that it was a perfect match for Streptopelia decaocto… a first for Dakar and for mainland Subsaharan Africa! I found at least 3 birds, but only got a poor sound recording and no pictures… so decided to head back out on Sunday afternoon on another family afternoon out. Same story – quickly found one bird singing high up in a dead tree, and managed to get a few reasonable pictures as well as a short recording of that same bird. Another was singing on the opposite end of the central pond, which at the moment is full of various herons and egrets, Long-tailed Cormorants and African Darters but also Black Crake,  Blue-breasted Kingfisher and Greater Swamp-Warbler (when I find a moment, I’ll write a little post on the birds of the park, which is really worth a visit at the moment since the large heronry is in full swing).

Eurasian Collared-Dove / Tourterelle turque (click to enlarge)

 

Identification

The Eurasian Collared Dove (or should it maybe be called the Global Collared Dove?) is not a species that we associate with identification challenges back in the Northern Hemisphere, but here in Africa there’s a closely related species, African Collared-Dove, which is extremely similar, so it’s useful to highlight key ID features here.

Not the most flattering shot, but the picture below nicely shows the long bi-colored tail and especially the grey undertail coverts, without any contrast with the rest of the underparts. In African Collared-Doves, the lower belly and undertail coverts are distinctively paler, almost white, whereas the rest of the body is much as in the Eurasian Collared-Dove. The latter is also slightly larger and longer-tailed than its African cousin, but other than that there are very few if any useful field characters, and separating these two doves on plumage & structure is very tricky. I suspect that when both species are viewed side by side the differences in size, shape and colours may be reasonably obvious, but without direct comparison it surely is a tricky matter.

Eurasian Collared-Dove / Tourterelle turque (click to enlarge)

The best ID feature is of course the song, which luckily is very different between the two species… and given that the Dakar birds were regularly singing this made their identification really pretty straightforward (and if it hadn’t been for their song, they probably would have gone unnoticed a bit longer!). I already tried describing the song earlier on, but the sonogram rendered below (thanks to Xeno-canto) nicely illustrates its structure, which is made up of three simple notes, typically uttered in series of 5 – 8 sequences each lasting about a second and a half (I only managed to record 4 sequences; listen to it here).

On hindsight, I’m wondering whether the dove that I saw a few months ago (16 & 18.12) from my balcony in Almadies really was an African Collared-Dove, as I didn’t check whether a wandering Eurasian Collared could be ruled out (it didn’t sing). Either way, it was a short appearance and so far the only time I’ve recorded a Collared Dove in Dakar, until the Hann sightings.

 

Origins… and destinations

I wonder of course how these birds got here. Would they have traveled all the way from the nearest breeding sites in Mauritania, or possibly from Saint-Louis where they may already be present for some time (but yet to be confirmed, as far as I know)? Or are they captive birds that were released or escaped? Or maybe even ship-assisted? One can only speculate of course, but the latter options seem rather unlikely given that I can’t imagine anyone here going through the trouble of importing Eurasian Collared-Doves, even more so in a country that holds another 4 species of closely related doves (African Collard, African Mourning, Vinaceous, Red-eyed), all of which are very or reasonably common. Or a dove jumping on a cargo ship in Europe or elsewhere and making it to Dakar in sufficient numbers to establish a breeding population, though why not. Of course I have no evidence yet that they are indeed breeding, but one can assume that they do, given that I easily found at least 3 different birds in a small area. Now if they came from Mauritania, then surely Saint-Louis and several other towns along the road to Dakar must already be inhabited – something to check out.

[Cool fact from AllAboutBirds.org: the origin of the US invasion is the Bahamas, where “several birds escaped from a pet shop during a mid-1970s burglary; the shop owner then released the rest of the flock of approximately 50 doves. Others were set free on the island of Guadeloupe when a volcano threatened eruption”]

In Africa, the Eurasian Collared-Dove first arrived in Suez in 1979 and (perhaps coming from the Iberian Peninsula) it went on to establish itself in Morocco (first sighted 1986) and Tunisia (1986 or 1991, depending on source); in Algeria the first record dates from 1994, and barely 3 years later, at the end of 1997, min. 130 birds were present in the eastern town where it was first sighted. Most likely it spread southward from Morocco where it is considered widespread and common since 1993-’98: it has now foot in the Canary Islands and possibly even the Azores (first recorded Sept. 2006), Mauritania (first recorded 1999, now well established in Nouadhibou and Nouakchott, among other locations – see the species’ page on the recently published online Atlas of the Birds of Mauritania), as well as the Cape Verde islands which were gradually colonised during 2006-2014 (with an old record of a bird at sea coming from a southwesterly direction, flying fast just above the water surface, and alighting at Pesqueirona, Sal, 9/4/96). The species is said to occur in the Aïr mountains in northern Niger according to a source from before 1990, but I could not find any more specific information on the occurrence in this part of the Sahara¹.

And now Senegal.

Where and when will their expansion ever stop? One could easily imagine that many of the major African cities – in particular coastal capitals – would gradually be colonised in coming decennia. From here, they may spread further south in the country and beyond, potentially reaching the large capitals of the Gulf of Guinea (Abidjan, Accra,…), thus following in the footsteps of the House Sparrow which now has even reached Brazzaville and Kinshasa (where I found several pairs with evidence of breeding just as recently as last January, and managed to dig up a couple of recent sightings posted online, but which so far had gone unnoticed).

The most up-to-date distribution map that I could find is the “live” map on e-bird, though admittedly it has many gaps as several regions (e.g. Central Asia, China) are not well represented,  but it definitely shows how widely the species ranges today, from Japan in the Far East all the way to Alaska, and from the tropics to beyond the Arctic Circle. This map comes close too².

 

One can only admire this unassuming little dove for its incredibly rapid range expansion – or invasion, depending on how you see this remarkable feat. All in a matter of less than a century. Curious to see where it will go next…

 

¹ All I have is that it’s listed as part of the avifauna of the Aïr and Ténéré areas, still within the Sahara region (source: La réserve naturelle nationale de l’Aïr et du Ténéré (Niger): la connaissance des éléments du milieu naturel et humain dans le cadre d’orientations pour un aménagement et une conservation durables : analyse descriptive : étude initiale. MH/E, WWF & IUCN 1996). It’s listed there as a Palearctic migrant, but no further details are given; the likely original source is Les osieaux de l’Aïr et du Ténéré.  Série des Guides Touristiques no. 2.  RRNAT (Newby & Canney, undated).

² Additional references: Handbook of theBirds of the World Vol. 4; Birds of the Western Palearctic Concise Edition Vol. 1; Birds of West Africa 2nd ed.; Oiseaux d’Algérie (Isenmann and Moali, 2000); various country pages on the website of the African Bird Club. And many thanks to Frédéric Bacuez, Joost Brouwer, Peter Browne, Wim Mullié, and Paul Robinson for providing information and references!

 

Advertisement