Author Archives: Jochen Dierschke

Responses to Oriental Cuckoo Post

by Jochen Dierschke

Many thanks to all comments either received privately or on this blog!

In the meantime I received some much better pictures taken bei Oliver Nüssen:

Kuckuck_20150527_ONuessen_08 Kuckuck_20150527_ONuessen_07 Kuckuck_20150527_ONuessen_05 Kuckuck_20150527_ONuessen_09

Especially the last picture shows that also the lesser underwing-coverts are faintly barred and that the primaries have too many white bars for Oriental. Some people suggested that this bird might be a female. I am not very experienced in sexing Cuckoos, but most pictures of birds I’ve seen ringed and sexed do not fit the bird.

In Summary: Although the bird looks like being within the variation of Oriental, it seems more likely to be a Common Cuckoo. As the calls were never definitely heard from the bird in question, it may have been a different bird calling. The calls heard were also “three-note-calls”, making an Oriental unlikely.

At least we learnt some lessons on Cuckoo-ID, but it seems a nightmare to get an Oriental Cuckoo accepted in Europe outside Russia!

Oriental Cuckoo on Helgoland?

Jochen Dierschke

A strange cuckoo has troubled our minds the last days on Helgoland. Could it be an Oriental Cuckoo, a species not yet recorded safely in Europe outside its Russian breeding grounds?


The Cuckoo in question (picture by Thorsten Stegmann). Note the dark upperparts, the tiny appearance and the barring on the underparts.


On May 25th, local warden Felix Timmermann checked in early morning ID features of birds for his forthcoming trip to the Ural mountains, including the voice of Oriental Cuckoo. Only an hour later, he heard a Hoopoe-like call. The call sounded like the introduction part of Oriental Cuckoo song, but the bird remained unseen. Felix informed me, but I had no time to check due to a breeding bird survey on the neighbouring dune island. The next morning, only a few hundred meters away, another Hoopoe-like call (three syllables) was heard, but again no sighting of the bird.

In the morning of May 27th, a “strange Cuckoo” was seen by several birders at the 2nd site. I became a bit excited and went to see the bird. When I saw it, I realized several features consistent with what I knew about the ID of Oriental Cuckoos, so I tried to take pictures, especially in flight. The bird then flew to the other side of the island and was relocated there and gave excellent views. A check of the literature suggested that we needed to trap the bird. In the evening we erected mistnets close to his favoured site, but although we played the female call, which is supposed to be good for trapping cuckoos, the bird was not seen again. Also next morning we tried to trap, but it seemed that the bird had finally taken of, with a lot of caterpillars in his belly.

Looking in the literature, it became evident that not a single feature is unique to Oriental Cuckoo (except the song), but a combination of the features pointed towards Oriental:

Size: The bird looked tiny and short-billed in the field

Upperparts: Rather dark for a Common Cuckoo; some retained tertials and secondaries indicate a 2nd-year bird.

Underparts: The belly-streaking was not as dense in Common Cuckoo. On the pictures we counted 7-8 complete black bars from belly to breast. The width of the black bars varied between postures, but certainly they can be more obvious in Oriental. The vent and undertail coverts produced a large, unbarred peachy-buffish patch. Only the longest undertail-coverts were more whitish with black bars.

Underwing: The bird showed a White’s Thrush like underwing pattern with a broad white stripe. The lesser underwing-coverts were unmarked and buffish. The primary barring was rather bold, but the exact number of white bars could not be counted, as the bases of the primaries are partially covered by the greater coverts.

As Common Cuckoo is quite rare on the island in spring, it seems unlikely that several birds were involved in the sightings. So, we face a Cuckoo which calls like an Oriental, looks at least to me like an Oriental – but is this enough for a 1st record for Europe outside the Russian breeding areas? The Finnish birds have not been accepted, as there were some features odd for Oriental, like a call of three syllables, wing length (see Lindholm & Linden 2003, Alula 4: 122-133). Also the Helgoland cuckoo uttered a call with three syllables. However, this might be just a disturbed introduction of the song.

Oriental Cuckoo has not been safely recorded in Europe outside the Russian breeding grounds. However, it certainly should be on the radar of European birders!

Any comments on the ID of the bird – good or bad news – are very welcome!




The Helgoland Cuckoo in flight from below. Note the obvious underwing panel, especially the unmarked lesser underwing-coverts. Note also the barring and the pattern of the undertail coverts.


Note the retained juvenile tertials and the pattern of the undertail coverts.

An extreme Black Redstart

by Jochen Dierschke

On 11.4.2015, local birder Gotthard Krug, well-known for his finds of rare birds on Helgoland, came across a red-bellied Black Redstart. He phoned me and as I was only a hundred meters away, could soon confirm the oddity of this Black Redstart.


Record shot of the Black Redstart – look how distinctive it is!

Although I had previously seen Black Redstarts with some orange at the belly, this one was by far the most obvious I’ve ever seen. Ssp. phoenicuroides has no white wing flash, but I was not sure if other red-bellied subspecies do. So I decided to trap the bird and within half an hour it was in the bag. BR_total_1

BR_wing formula

Total view of the bird and wing formular; note the typical Black Redstart primary spacing.


Underpart colouration of the red-bellied bird (left) compared to a normal adult male (trapped today).

The bird, an adult male, was with 90 mm wing-length close to the upper limit of Black Redstarts and also the wing formula with the large step in the primaries was in line with this species. A quick check at home in the literature confirmed that no eastern subspecies shows this white wing flash and the primary spacing was against a hybrid (although this can not fully be excluded). Therefore the bird was a Black Redstart, though a rather unusual one.

 If this belly pattern can be shown also by the paradoxus-plumage-type, the ID would possibly be not that straightforward!

Lightning sometimes strikes twice – Grey-necked Bunting on Helgoland

by Jochen D.

One of the worst birds I ever dipped on Helgoland was the 2009 Grey-necked Bunting – I left the island the day before (as many other birders). With only a handful of records in northwestern Europe the chances of seeing one on Helgoland again seemed rather low.

The morning of June 10th 2013 did not have much to offer birdwise. So I used our noon break at the bird observatory only for a short walk and then wanted to have a short nick. I was lying ca 2 seconds, when my mobile rang – as always. My assistant Klaus has just seen an Ortolan Bunting with an all grey head, but a tourist had flushed it and he could not find it back. Adrenalin was spreading fast – the Cretzschmar’s Bunting in the Netherlands was still in my mind, so I rushed to the football pitch. Still no sign of the bird, but after spreading out I flushed a reddish bunting calling unfamiliar “pit”. That was the bird and it did indeed sound neither like an Ortolan Bunting, nor like a Cretzschmar’s (although I had seen the latter only 20 years ago in Israel). Finally I saw the bird sitting and immediately identified it as a Grey-necked Bunting – the 2nd for Helgoland! Adrenalin had dropped little and now reached its peak …


There were only a handful of birders on the island and all managed to see the bird soon. Also the first two twitchers arrived by plane and managed to connect with the bird. Photographing the bird was rather difficult, as it was rather shy and flew off in ca 20 meters distance. And joggers, walkers, dogs etc made the bird staying at the same place only for a few minutes.


The 2nd day proved even more difficult – the bird was not seen in the morning, but found back around noon on the opposite site of the island. Twitching proved to be difficult as well: The first day only 3 birders arrived and were lucky to arrive in the moment the bird was refound. The last 2 days it was seen only for minutes during the day (usually best in the evening). So far only ca 15 birders came to see the bird, but if it remains until the weekend, more birders probably will arrive.

The habitat was open land with sparse (=steppe) vegetation or edges of tracks. It was usually feeding a bit hidden in the grass, hopping into the open and returning into the vegetation.


The ID of the bird was rather straightforward: Typical Ortolan Bunting head, long-billed, a moltoni-like underpart colouration. The best clue to refind the bird was it’s distinctive flight call. So far I did not manage to obtain a decent recording, but a Bunting calling “pit” should always raise the alarm bells.


British or Yellow-headed Yellow Wagtail?

On Helgoland, the British Yellow Wagtail (Motacilla flava flavissima) used to breed in the 1920s and 1930s, but then disappeared due to rats. Since it is a scarce spring migrant with the occasional breeding record (the last in 1977).

On April 17th I was happy to add this taxon (regarded as a species in Germany) to my garden list, when the local sheep broke into the neighbouring garden, followed by a flavissima. The following day, the same happened again and I could see 2 males and a female flavissima as well as a male flava from my kitchen table. Together with Martin Gottschling I went out for photographing these birds and we noticed a Citrine Wagtail like rasping call – THE signal to check any Yellow Wagtail more closely, as there are many vagrant taxa from the south and east using this call. However, the flava male had already disappeared and only the 3 flavissima (2 males and a female) were present. While one male and the female called normally, the other male always used the Citrine Wagtail call, as far as we could see/hear.


This is the bird in question – looks like flavissima to me!


Sorry, my sonagram skills are still juvenile …

You can listen to a recording of the call >HERE<

So, could it be a Yellow-headed Yellow Wagtail (Motacilla flava lutea)? This taxon is still on the German list due to 2 records on Helgoland, which were recently rejected by the Helgoland Rarities Committee, as lutea and flavissima are not safely identifiable in the field and no call was recorded. These birds looked like lutea, but such extremes are apparently regularly recorded in the British breeding population of flavissima. So this time, it is the other way around: We have a bird only obvious by the rasping call. By the plumage features, I wouldn’t hesitate to call this bird a flavissima, though perhaps on the brighter side of the majority. However, is the call a safe ID-feature of this taxon?

Checking the literature, I found some hints only:

Alström & Mild (2003): Pipits and Wagtails of Europe, Asia and North America.

p. 281: “… Accordingly, vagrants outside their normal ranges cannot be identified with certainty, except perhaps by voice (see Voice).

p. 300-301: The call of flava, flavissima, beema and thunbergi … given both in flight and from the ground … is a rather loud pseeu, pslie, psie or similar …Also gives a slightly sharper psriee or tsriee (in combination with the above-descibed notes), which is possibly a less harsh variant of the alarm call (but is used as a normal flight-call).

The subspecies lutea apparently uses both ‘feldegg-type’ and ‘flava-type’ calls … We have not heard any lutea that switched between the two call-types (more research on the calls of lutea is needed).

Van Duivendijk (2011); Advanced Bird ID Handbook.

For lutea and flavissima no voice-feature is given, although in other taxa, the rasping call is mentioned in opposite to north-western Yellow Wagtail taxa

So, what does this tell us? Although flava and thunbergi might utter occasionally a harsher call, birds calling constantly like this should be of another taxon. Nevertheless, I think it is very unlikely that lutea and flavissima meet on Helgoland in a flock rather early in the year. A southeastern Yellow Wagtail I would expect to appear rather later in spring, as e.g. feldegg does, although there are some rather early records (e.g. last week). Southwestern vagrant taxa however seem to appear rather early in the year (there were already quite a few observations this spring in southern Germany).

To me this is just a flavissima. But if flavissima can call like this, then Rarities Committees should reconsider, if the call should be really the clincher for the ID of vagrant Yellow Wagtail taxa.

Strange Great Tit calls – invasion from the east?

Although some pairs of Great Tits breed annually on Helgoland, the majority of birds occurs during migration. Every few years, numbers are much larger than in other years, usually corresponding with large numbers in southern Sweden. However, most ringing recoveries are from the southern Baltic Sea coast. Most Tits (Great & Blue) arrive on Helgoland during easterly winds, often, when there is fog at the coast.

Since mid of October, large number of Great Tits are present on Helgoland, as often in invasion years. However, this autumn they are calling different. Most birds have a call, which is similar to a much discussed Chiffchaff-call, it sounds even a bit similar to Hume’s Warbler. It’s a “wieh-wieh” call, sometimes a single , usually a double and sometimes a triple-call, often included in a series of other calls. When you hear it the first time, you don’t think it’s a Great Tit, but more a strange Phylloscopus warbler! Now I am used to the call and adrenalin-level keeps low, but I never heard this call before, and now the majority of Great Tits utter this call!

Listen here to the calls (recorded by Matthias Feuersenger and Ralph Martin on Helgoland in October 2012).

You can see some sonagrams and listen to some more samples here (although the text is mainly in German):

When I discussed the calls with other birders, none of them claimed to have heard the call ever before, although it seems likely that a single bird would have been noticed as one of many variations of Great Tit calls. Now they seem to be all over Germany, from the south to the north.

Are we experiencing an influx of breeding areas which have not been source of invasions before, like the Bullfinches in 2004? This autumn there are many recoveries from the Baltic states, but there they are ringed on migration, so the origin of these birds must be further east or northeast. Searching on, Matthias Feuersenger found 2 calls from Russia which sounded similar. They were recorded at Cheboksary, Chuvashskaya Respublika, Russia (56,0° N, 47,3°E, 700 km east of Moskau).

So is this the origin of the birds? Are they all over Europe now or just in the central part? Will they appear now annually in Europe?

Even in common and well known species like Great Tits there are mysteries which are not yet solved!

Thanks Matthias & Ralph for allowing me to use your recordings and for discussions!

Influx of Greenish Warblers?

by Jochen

It has been an excellent spring for Greenish Warblers in Germany with several breeding records and stragglers far away from the more regular sites. Late August is the best time in autumn for this species on Helgoland, as you can see in the histogram below. Shown are all records on Helgoland (n = 99) from 1840-2009, taken from the book “Die Vogelwelt der Insel Helgoland”, published in 2011 (see


So I was not very surprised when a few days ago I heard a Greenish Warbler calling just in front of my window. It was constantly calling very loud, but I was phoning with my chief, so I could not concentrate too much on the bird. When the phone call was finished, it stopped calling and I saw it flying over the roof, never to be seen or heard that day again. Next day it was again calling at the same site, but I could not find the day. Finally, on 24.8. I heard the bird again (once it was even singing) and saw it for a few seconds. The fresh plumage indicated a first-year.

Also on 24.8., I was mist-netting on another part of the island, but catching was rather slow, so I went around with my bins and saw another Greenish Warbler. It was an obvious first-year bird with a strong contrast between a greyish green back and bright greenish primary edges. Another birder took some pictures, then I had to check the mistnets again.


Picture taken by Jan-Peter Daniels

When I went back to the site 2 hours later, I played the Greenish Warbler call and immediately a bird popped up. I thought the bird is back, however, this bird had a different upperpart colouration and therefore was a 3rd bird, also a first-year. It showed well for a few minutes and I was able to take some pictures:


So 3 first-year birds on a single day – this has never been experienced so far on Helgoland on autumn migration (although several times in spring). Is there an influx going on?