Category Archives: 09) Skuas, Gulls, Terns

Saunders’s and Little Terns ID pitfalls


Yoav Perlman

This is a topic I talked about briefly in my 2015 Spurn Migfest talk. Saunders’s Tern is one of the rarest and least-known breeding birds in the WP. Despite having a large range around the Indian Ocean, including Red Sea, coastal East Africa, Arabia and Indian Subcontinent, it is still a poorly-known species worldwide. ID of adults in summer is better described. Compared to its sister Sternula species, Little Tern, it is smaller and slimmer. Seeing them side by side (I have seen two in Israel alongside Little Terns), you get a similar comparison to Common versus Arctic Tern in differences in size, structure and derived flight pattern – about 10% smaller and more delicate, and flight more light and bouncy. Calls are also different – check the Xeno Canto page with lots of variation in call but the mainstream seems to be softer and less coarse than Little Tern. Some plumage features seem to be rather robust – first of all, contrary to what some birders may think, adult summer Saunders’s are paler above than adult little, very pale silvery-white. They have a larger dark primary patch, usually 4-5 dark primaries, compared to the normal 2-3 dark primaries in adult Littles. Also, Littles have a contrasting white rump and tail, at least the outer tail feathers (apprently greyer central tail feathers are quite normal in Little Terns). Saunders’s has concolorous (pale) grey mantle, rump and entire tail. And that’s it more or less. All the other features mentioned in literature are of unknown validity, mainly becuase the limits of variation within Saunders’s Tern, even adults in summer plumage, are little known.

But that’s not the only reason why separating these two species is challenging. Interestingly, the amount of variation shown by adult summer Little Tern, which is such a familiar and popular European bird, a photographer’s favourite, is not well described. More on this below.

My interest in them increased a few months ago. I noticed this Saunders’s-type tern in a blogpost of my good friend from Kuwait, Mike Pope from late April 2015:

Tern sp. with little Tern in background, Sea City, Kuwait, 25/4/15 by Mike Pope

Tern sp. with little Tern in background, Sea City, Kuwait, 25/4/15 by Mike Pope

This bird made some alarm bells go off – look at this broad wing patch (4 primaries), concolorous rump and complete grey tail – this must be a Saunders’s Tern, no? I flagged it up to Mike, he circulated among some experts, and the views were leaning towards Saunder’s tern – that would have been a long overdue first for Kuwait.

But then the plot thickened. I circulated Mike’s report among my fellow IRDC members. Yosef Kiat has been ringing Common and Little Terns for several years now in a breeding colony at Atlit, south of Haifa, on the Med Coast. He sent me some images of Little Terns from the breeding colony this late summer that knocked me off my chair. I was aware of the variation they show there, I did join him several times on his nocturnal adventures there, but have never seen extreme birds like these. First, a 2cy bird – this bird hatched in the colony to ‘normal’ looking Little Tern parents in 2014, and was retrapped this year:

2cy Little Tern, Atlit, israel, 25 August 2015 by Yosef Kiat

2cy Little Tern, Atlit, israel, 25 August 2015 by Yosef Kiat

Look at the grey rump and tail: perhaps outer tail feathers are slightly paler than the heavily abraded and dirty central tail feathers, but I am sure in the field this would look like a solid grey tail.

And take a look at this 1cy bird, hatched 2015, again to’normal’ Little Tern parents, wow!

1cy Little Tern, Atlit, 1/9/15 by Yosef Kiat

1cy Little Tern, Atlit, 1/9/15 by Yosef Kiat

Hmmm…. Grey rump, grey tail… And the wing looks like this – in the field it would look like a huge dark wedge:

1cy Little Tern, Atlit, Israel, 1/9/15 by Yosef Kiat

1cy Little Tern, Atlit, Israel, 1/9/15 by Yosef Kiat

Also this summer, in June, Yuda Siliki, an Israeli birder sent me this nice comparison of Little Terns from Ma’agan Michael – these birds are from the same colony in Atlit. Check out the variation in supposed features for Saunders’s Tern – shape of forehead patch and extent of dark bill tip. Saunders’s has much more limited white foreahead, not unlike the lower individual, but the white patch needs to more squared off in Saunders’s, less of a supercilium above and behind the eye, but still check the amount of variation among the two. Also, what about the amount of dark on the bill tip? Saunders’s should have more extensive dark than little, so what’s going on here?

Adult Little Terns, ma'agan Michael, Israel, 7/6/15 by Yuda Siliki

Adult Little Terns, ma’agan Michael, Israel, 7/6/15 by Yuda Siliki

I think it is very interesting to explore this species pair now. They were found breeding only recently in southwest Sinai, just 150 km away from the Mediterranean. For a long-distance migrant to hop into the Med is no big deal, and then it could practically turn up anywhere around the Mediterranean. An adult in summer plumage should be possible to pick out among Little Terns, but what about a young bird? and a non-breeding bird? Headache. If you read carefully Klaus Malling Olsen’s tern book he does state that in non-breeding and juvenile plumages it would not be safe to separate the species. With the circumstancial evidence provided here I tend to agree, but it is hard for me to accept that they cannot be separated. There must be something out there to teach us.

This is how some Saunders’s Tern breeding in Sinai look like – many thanks to Rich Bonser for allowing me to use his brilliant pics. Adults have a nice prominent wing patch, but only three dark primaries here. Is it moulting? Unclear. It has a small forehead patch, that doesn’t extend above and behind the eye:

Adult Saunders's Tern, Ras Sudr, Sinai, Egypt, July 2013 by Richard Bonser

Adult Saunders’s Tern, Ras Sudr, Sinai, Egypt, July 2013 by Richard Bonser

Difficult light conditions here. Rump is grey – however in this image tail looks paler?

Adult Saunders's Tern, Ras Sudr, Sinai, Egypt, July 2013 by Richard Bonser

Adult Saunders’s Tern, Ras Sudr, Sinai, Egypt, July 2013 by Richard Bonser

This bird in better light conditions does show the rump and tail pattern nicely. It is in active primary moult, so wing patch much reduced here:

Adult Saunders's Tern, Ras Sudr, Sinai, Egypt, July 2013 by Richard Bonser

Adult Saunders’s Tern, Ras Sudr, Sinai, Egypt, July 2013 by Richard Bonser

More extensive white forehead patch here, but again does not extend back above eye:

Adult Saunders's Tern, Ras Sudr, Sinai, Egypt, July 2013 by Richard Bonser

Adult Saunders’s Tern, Ras Sudr, Sinai, Egypt, July 2013 by Richard Bonser

Very pale silvery white above. Solid dark bill tip as in all photos. There is some talk about Saunder’s having duller leg colour but I think this feature is not worth much. This is so dependent on the hormonal condition the bird is in during breeding. Also bill tip must change according to breeding condition?

Adult Saunders's Tern, Ras Sudr, Siani, Egypt, July 2013 by Richard Bonser

Adult Saunders’s Tern, Ras Sudr, Siani, Egypt, July 2013 by Richard Bonser

This one below is a 1cy. I do not know if the colony at Ras Sudr is mixed with Little Terns or not, but in Rich’s blog this is a 1cy Saunders’s Tern – I will go with the flow. Not dissimilar to the Atlit 1cy Little Tern above? Pretty pallid bird but extensive wing patch. Greater and lesser primary coverts very dark here, but is it different to how the Atlit 1cy would look like in the field? I am not sure.

1cy Saunders's Tern, Ras Sudr, Sinai, Egypt, July 2013 by Richard Bonser

1cy Saunders’s Tern, Ras Sudr, Sinai, Egypt, July 2013 by Richard Bonser

1cy Saunders's Tern, Ras Sudr, Sinai, Egypt, July 2013 by Richard Bonser

1cy Saunders’s Tern, Ras Sudr, Sinai, Egypt, July 2013 by Richard Bonser

It would be great to study the amount of variation the Sinai Saunders’s Terns show in key features like forehead patch, bill tip and tail pattern. Also how many dark primaries do they have before moult?

One incredible place to study Saunders’s Tern in non-breeding would be Kenya. I visited Sabaki river mouth, north of Malindi in December 2010. There is a roost of hundreds of thousands of Saunders’s Terns (!) there during the northern winter. I was there at daytime so there were only few thousands… But they were all distant, and scoping them into the sun didn’t provide me with much insight on their ID. I wonder if anyone rings them there, or at least photograhps them.

But one very important piece missing in the jigsaw is how much variation ‘our’ Little Terns show, in adult summer plumage and also in other plumages. Does this variation that I have shown here in Israeli birds occur in northern populations as well? The Little Terns I have seen here in the UK looked all bog standard, but I didn’t study any juveniles. I guess that few 2cy Little Terns return in summer to N Europe? Would be great to get some feedback from ringers and birders with field experience.

Variation in first summer Great Skuas

Off Flamborough and the Azores

Moult matters!

It’s almost October. The best month… potentially… to get a South Polar Skua.

Learning to read moult scores may well secure Britain’s or NW Europe’s next SPS. From now on (peaking October?)  the loop migration of South Polar will take individuals closer to Europe than at other times.

With a summering Great Skua at Flamborough (previously featured) and photos of 2 birds off the Azores last April, I found it a useful exercise to be a bit more genned up. Dick Newell who has spear-headed much though on large Skua ID and moult kindly chipped in.

In June – July 2015 one notable Great Skua summered off Flamborough. The bird occasionally came close enough to capture some images. I posted HERE to open discussion. In the final analysis I change my gut reaction view and now I think the bird is in fact a first summer (2cy) individual (‘cos I am slow and some folk helped me!)

Reading Moult Score. Only new feathers score points

Let’s keep it simple for now.

The birds (skuas in this case) have OLD primaries, NEW primaries and primaries in various stages of REGROWTH, once the old feather has actually fallen out. Each of these stages can be scored.

P.S. you know I am only doing for myself, as I can never remember and need quick reference spot :)

OLD: If the feather is still present and OLD – NO POINTS- NOTHING!

NEW: If the feather is fully grown and NEW – full 5 POINTS

REGROWING: and here’s the slightly more tricky bit…

If the feather is NEW and regrowing but incomplete:

new feather NOT visible (in pin) 1 POINT

new feather visible and c 1/3 grown 2 POINTS

new feathers visible and c 2/3 grown 3 POINTS etc

That’s very roughly it! So only NEW feathers get POINTS whether fully grown or part grown or the gap where there are growing (in pin). Easy!

Flamborough, late June

A first summer Great Skua- moult score 32. Three old outer primaries (no points). Five new fully grown inner primaries. 5 x 5 = 25 points. then Dick has found 7 more points. Hmm need to check where he’s got them from…  Have I got that right?

Great Skua 28th June M Garner d (1 of 1)Great Skua 28th June M Garner a (1 of 1)Great Skua 28th June M Garner e (1 of 1)Great Skua 28th June M Garner g (1 of 1)





Dick Newell:

“Moult score of about 32 on 28th June puts it in the zone of 1st cycle Bonxie or very early moulting older South Polar – which is not a contender for SPS on plumage.”

Flamborough- same bird – now mid July

Bonxie boy (1 of 1)

Flamborough – different bird? – 15th August

Thanks to Craig Thomas for these pics. Watched this one fly close and it was not too tricky to age as a first summer Bonxie (Great Skua). This bird is just completing its primary moult. This is a ‘classic’  first summer/2cy in which the streaking etc is more limited to the mantle and scapulars/central body strip in flight but the upperwing is relativly plain and unstreaked (adults heavily streaked). Lots more in first Challenge Series: AUTUMN.

15-08-17 Bonxie image 2 15-08-17 15-08-17 Bonxie Flamboro


Azores – April

Peter Howlett sent these photos to the Birding Frontiers team for comment. Not an easy subject and with different climatic conditions, some birds in this region, even though they are also first summer Great Skuas, can be far paler, more bleached and frankly carry of a nice South Polar Skua search image in their appearance.

They often provide a South polar pitfall!

“I’d like to have your (and the team’s) opinion on these skuas I photographed just south of Sao Miguel, Azores on 13 April this year.

Reply from Dick Newell:

Hi Martin (and Peter),

How nice to hear from you and thank you for sending this.
The bird with a primary moult score of ~25 on April 13th is overwhelmngly likely to be a 1st cycle Bonxie. It would be a rare event for a South Polar to have this score on this date. Apart from which, it looks like a Bonxie and doesn’t have the compact profile of a South Polar – but that’s subjective stuff.

The second bird looks pretty similar to the first bird, so, on those grounds it is probably also a Bonxie. The primary moult score of ~2-4 makes it marginal. An older than first cycle South Polar could have this moult score (just), but more likely a late-ish 1st cycle Bonxie.

It would be unusual for a South Polar to look as mottled as these birds. The dark hood is also a point against, though can happen on a South Polar.



Sao Miguel

Sao Miguel

Sao Miguel

Sao Miguel



Sao Miguel

Sao Miguel

There’s a wee warm-up on skuas, ageing and moult scores. While passerines may dominate my desk for the next couple of weeks… we are also entering a South Polar window.


(Stunning!) juvenile Baltic Gull type

Check this one out!

by Hans Schekkerman

“When I found this juvenile gull standing between a ‘normal’ juvenile LBB and a Common Gull it was about half way between them in size, but structurally closer to the Common Gull! Unfortunately it didn’t wear a ring, but in my opinion everything points at Baltic Gull –it even seems to be on the ‘extreme side’ of Baltic plumage variation in several characters, e.g whiteness and lack of marking on head and underbody, and total lack of notching and barring on (particularly) greater coverts. I haven’t found a Baltic Gull photo yet with such plain greater coverts, but it seems even more unlikely that a graellsii or intermedius could show this.

Any thoughts or opinions would be appreciated,


Hans Schekkerman”


Field Appearance

Very conspicuous among the other gulls on the beach – including a few 100 ‘normal’ juvenile Lesser Black-backs, by small and delicate build as well as contrasting plumage. Differences with ‘ordinary’ juv LBBG:
(1) Strikingly smaller and more slender; size between LBB and Common Gull, but shape closer to Common.
(2) Very long wings creating elongated body. Primary projection 2.4 times tertial length beyond greater coverts. Depending on posture, 5 or 6 primary tips visible, with P10 3-5 mm > P9.
(3) Head smaller, more ‘friendly’ with rounded crown.
(4) Less heavy bill, rather straight with flat gonys.
(5) Shorter legs (also looking somewhat thinner), contributing to elongated impression.
(6) Head almost white with fine grey-brown streaking mostly confined to shadow patch before/below eye, crown, hindneck and rear ear coverts, and white cheeks neatly demarcated from grey-brown barring on neck sides.
(7) Underparts strikingly pale with less grey-brown patterning on white ground-colour; upper breast, belly and vent almost unpatterned white.
(8) Upperparts with almost pure white feather edges contrasting with cold grey-brown centres; no warm brown or buff hues present.
(9) Edges of wing coverts (particularly greaters) and tertials with hardly any notching, creating a completely unbarred (but rather striped) lower closed wing. (Such plain greaters must be rare even in Baltics?).
(10) Narrower black tail-band than typical contrasting with weakly patterned rest of tail, uppertail coverts and rump.
(11) Underwing basically white or very pale grey with restricted brown streaking on coverts.
(12) Hardly any pale tips visible on primaries (small pale tips in majority of LBBG).
Some aspects of the bird reminded of a young Caspian Gull but in the field this impression was counteracted by the short legs, shortish-looking neck and wrong upperwing pattern in flight.

That is no normal baby Lesser Black-backed Gull!



with a 1cy Lesser Black-backed (below)9529785


with a 1cy Herring Gull (below)9529789


on da beach9549874


Oof- underwing with magic whiteness…9549921


and a whiter rump and tail…9529802


please can I have one this autumn :)9549874,,

Flamborough 2014



Baltic Gull

Keep lookin’

It was just over a year ago (26th July 2014) that Craig Thomas and I had an excellent first summer Baltic Gull off Flamborough Head. I could add ‘candidate’ but it just looked too good to use caveats :)

It gets a little harder in August but 2cy Baltic Gulls can still be expected. The Large Gulls now start to get very interesting.

A reminder of what to look for in this distinctive plumage  >>>>HERE<<<<

2cy Baltic Gull Nokia Koukku dump, SW Finland 20.7.2007. Photo: Hannu Koskinen

2cy Baltic Gull Nokia Koukku dump, SW Finland 20.7.2007. Photo: Hannu Koskinen

Above: A 2cy Baltic Gull in late July and below and a 2cy one in mid-November

2cy Baltic Gull, Israel, November 2012. Martin Garner

2cy Baltic Gull, Israel, November 2012. Martin Garner



juvenile Yellow-legged Gulls

michahellis– NOW!

It’s that time of year. Can I reminisce momentarily? Just 20 years ago juvenile and first winter Yellow-legged Gulls were rarely identified with any confidence. There seemed just too tricky and confusing! I remember trying to unravel the riddles.

Slowly but surely a picture began to emerge. Lots of practice with close-up juveniles of Herring and Lesser Black-backed Gulls helped a lot.

Are you there yet? There are always a very satisfying local find.

Right now juvenile/ 1cy Yellow-legged GUlls are flung far and wide. Almost daily off Flamborough they are about and waiting to be found :)

So it was nice to ogle over these close-up photos by Brett Spencer of two young michs taken 2 days ago in Dorset.

_MG_7533 _MG_7660

2 photos above, 1cy Yellow-legged Gulls (michahellis) Dorset , 26th July 2015, Brett Spencer.


Chris Gibbins has just returned from Spain, so to add to the visual preparation, here are more young michahellis showing the striking upperparts in flight, especially the tail pattern. Also some more variation in plumage. Good luck!

4D2A80054D2A76164D2A94813 photos above, 1cy Yellow-legged Gulls (michahellis) Spain, July 2015, Chris Gibbins.


Great Skuas summering off Flamborough

and them Pomarines

Martin Garner

Great Skua 28th June M Garner f (1 of 1)

Skua watching has been unusually good off Flamborough this June. However it’s not of the expected species. Up to 7 Pomarine Skuas and several Great Skuas seem to be summering in Bridlington Bay. Most individuals, especially the Pomarines appear to be immature birds as might be expected.

This Great Skua came particularly close this morning. The dark ‘hooded’ head and pale base to the upper mandibles indicate this should be an immature bird. I might take a stab at it being a 2nd summer. I haven’t looked into any literature but it would be interesting to see if the details in the photos can lead to a more definitive ageing.

Have a look:

Great Skua 28th June M Garner d (1 of 1)Great Skua 28th June M Garner a (1 of 1)Great Skua 28th June M Garner e (1 of 1)Great Skua 28th June M Garner g (1 of 1)

Ivory Gull in Varanger

I Never Dreamed…

Ooo… just missed turing up for the 2015 Gullfest. Still must a bit heart soul and body warming encounter for Simon Colenutt and Trevor Codlin in Vardo harbour  who found this adult Ivory Gull at the start of this week (22nd March 2015). Read  Biotope’s account of the Ivory Gull at Vardo,

Simon writes: ‘What a cracking bird! I never dreamed of finding Ivory Gull!”

Read more of Simon and Trevor’s visit at ‘The Deskboundbirder’

Check out that head shot!

Ivory oneb (1 of 1)Ivory one (1 of 1)Ivory onec (1 of 1)Ivory onea (1 of 1)