Research Royal revelations


This page contains 4 reader comments. Click here to view (latest Tue 23/05/17 13:51).

Scientists and conservationists have confirmed the existence of a 'new' species of tern.

Royal Tern (Thalasseus maximus) was previously considered to comprise two subspecies: American maximus and West African albididorsalis. Wildlife conservationists in The Gambia have long suspected that West African birds were distinct, and now scientists at the Universities of Aberdeen and Montpellier have used DNA analysis to confirm that they are indeed two different species.

The research, published in the Biological Journal of the Linnean Society, analysed DNA sequences of feathers and other remains of West African Royal Terns from Mauritania and from islands off Tanji Bird Reserve, The Gambia. It was the first time that the DNA of albididorsalis has been sequenced. The researchers found that the DNA of West African Royal Tern matched most closely to Lesser Crested Tern (Thalasseus bengalensis). Therefore, in spite of the strong morphological similarity between albididorsalis and maximus royal terns (it is currently widely accepted that the two are almost inseparable in the field), they are not each other's closest relatives. Simultaneously, the distinctly smaller and readily distinguishable Lesser Crested is in fact the sister taxon of albididorsalis.

Despite considerable morphological differences, West African Royal Tern (back) is closer to Lesser Crested Tern (front) than it is to American Royal Tern (Photo: Daniel López Velasco)

Surprising genetic results are not unprecedented among Thalasseus terns. Though the results of the study come as a surprise and the splitting of royal tern into two morphologically near-identical species will inevitably pose new challenges for field birders, it only reflects the 2009 findings that the near-identical (at least in adult plumages) Palearctic Sandwich Tern and Nearctic Cabot's Tern were genetically distinct, which led to their treatment as separate species. The latter was found to be genetically closer to the distinctly different-looking Elegant Tern (Efe et al., 2009).

Royal Tern
Essentially indistinguishable from African on field views, the best clue that this is an American Royal Tern is the multitude of Laughing Gulls in the foreground! (Photo: Craig Nash)

The discovery could have immediate conservation consequences for West African Royal Tern, as its population is threatened by the erosion of its breeding grounds due to climate change and human activity. The results of the research will be presented to international conservation authorities in a bid to have its conservation status re-evaluated.

Royal Tern
With its richly coloured bill, this vagrant royal tern seen in Co Mayo in August 2016 was suspected to be American maximus. However, overlap in characteristics makes determining this in the field nigh on impossible (Photo: Dermot Breen)

Professor Martin Collinson, from the University of Aberdeen's Institute of Medical Sciences, explained: "West African and American Royal Terns have long been considered the same species. They look pretty much identical to each other except the American Royal Tern is on average slightly bigger with a slightly redder bill.

"This research should have an impact on the West African Royal Tern's conservation status. The breeding grounds in The Gambia and Senegal have been massively eroded by storms and the encroaching human population, so the West African Royal Tern is under threat. Conservationists in The Gambia can now take this information to their Government and potential donors, and call for help to protect this West African endemic species.

"It's information that can inform conservation priorities. There is a limited pot of money and information such as this helps determine where it should be allocated. It is important to direct conservation funds to preserve the maximum amount of genetic variation and genetic biodiversity, in addition to understanding the inherent societal, cultural and economic importance of the birds themselves."


Collinson J M, Dufour P, Abdulmaula A H, Lawrie Y, Elliott M, Barlow C & Crochet P-A. 2017. When morphology is not reflected by molecular phylogeny: the case of three 'orange-billed terns' Thalasseus maximus, Thalasseus bergii and Thalasseus bengalensis (Charadriiformes: Laridae). Biological Journal of the Linnean Society. DOI: https://doi.org/10.1093/biolinnean/blw049

Efe M A, Tavares E S, Baker A J & Bonatto S L. 2009. Multigene phylogeny and DNA barcoding indicate that the Sandwich tern complex (Thalasseus sandvicensis, Laridae, Sternini) comprises two species. Molecular Phylogenetics and Evolution 52: 263–267.

Related pages

Royal Tern Royal Tern

Related articles

Research Swamphens signal dominance with fleshy faces Research Swamphens signal dominance with fleshy faces
What's in a face? In addition to their plumage, Australasian Swamphens convey information about their status through their faces. read on read on
Research Male birds adjust courtship behaviour based on social context Research Male birds adjust courtship behaviour based on social context
A new study, published in The Auk: Ornithological Advances, explores how male Dark-eyed Juncos adjust their courtship behaviour to their social landscape. read on read on
Research Geolocators reveal Connecticut Warblers' amazing migration Research Geolocators reveal Connecticut Warblers' amazing migration
A new study has revealed the monumental transoceanic feats of Connecticut Warblers during autumn migration. read on read on
Research Male body mass is crucial to Wandering Albatross' future survival Research Male body mass is crucial to Wandering Albatross' future survival
A new study has suggested that the body condition of male Wandering Albatrosses will play a big part in the species' continued survival. read on read on
Research Tracking devices significantly burden migrant warblers Research Tracking devices significantly burden migrant warblers
A new study has found that geolocators negatively impact the chances that migrant Cerulean Warblers will complete their migrations and return to their territories the following year, which has in turn given researchers a serious dilemma. read on read on

The information in this article was believed correct at the time of writing. BirdGuides accepts no responsibility for errors, or for any consequences of acting on information in the article. The opinions expressed are those of the author(s) and are not necessarily shared by BirdGuides Ltd.

hide section Reader comments (4)

And with such news those whose only Royal Tern in Britain/Ireland is one not analysed at the genetic level will lose a tick. :(
   Jeff Higgott, 15/03/17 18:32Report inappropriate post Report 
Come and get the Guernsey one - it's still around and wearing an American ring.
   Jamie Hooper, 16/03/17 14:05Report inappropriate post Report 
bill shapes look different in this limited set of photos. shorter and fatter in american, longer an slimmer in WA. not sure if this holds up in measurements
   Mark Welfare, 16/03/17 21:07Report inappropriate post Report 
Great blog! Currently I must going to write my essay about birds. So I looking for best essay writing services
   Dave Adams, Tuesday 13:51Report inappropriate post Report 

Back to top Back to top

Latest edition Latest edition
Search articles Search articles
All articles All articles
Popular articles Popular articles
Privacy Policy | Terms of Use | Terms of Sale | Cookie Policy | About us | Advertise | Contact us
BirdGuides, Warners Group Publications PLC, The Chocolate Factory, 5 Clarendon Road, London N22 6XJ
© 2017 BirdGuides and Warners Group Publications plc. All Rights Reserved. Company Registered in England no. 2572212 | VAT registration No. GB 638 3492 15
Sales: or tel. 0800 919391 · International Sales: +44 (0)1778 391180 · Office: or tel. 020 8826 0934

Fatbirder's Top 1000 Birding Websites