Author Archives: Magnus Hellström

Yet another potential Stejneger’s Stonechat from Finland

By Magnus Hellström

“…during the examination Kari and Jarmo discovered that the bird showed a distinct and rather large dark marking in one of the birds’ uppertail-coverts. The marking was blackish and extended from the shaft out on the inner vane of the feather, perfectly matching the ‘class 2B markings’…” 


On October 4, Finlands second stejnegeri-candidate for the autumn was found at Kristiinankaupunki (the first one can be seen in a blogpost from Martin here). The bird was trapped by Kari Korhonen and Jarmo Pirhonen and was identified as a 1cy male. The width of bill at the proximal edge of the nostrils was measured to 4.5 mm which, according to Svensson (1992), place this bird outside the range of stejnegeri (4.7–5.7 mm, compared to 4.0–4.9 mm in maurus). However, during the examination Kari and Jarmo discovered that the bird showed a distinct and rather large dark marking in one of the birds’ uppertail-coverts. The marking was blackish and extended from the shaft out on the inner vane of the feather, perfectly matching the ‘class 2B markings’ shown and discussed in Hellström & Norevik (2014).

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Note the marked uppertail-covert. Photo: Jarmo Pirhonen

Similar markings are found on c. 40% of the 1cy male stejnegeri that passes through Beidaihe, E China, during the autumn migration, while such bold markings are, to present knowledge, not known to occur within maurus. The dark marking was found in one single uppertail-covert feather only, but such sparse/irregular distribution of the markings is regularly seen also in the E Chinese birds.

A feather was collected, and subsequent genetic analysis will show whether or not this bird qualify as a stejnegeri (as suggested by the overall appearance and the pattern of the uppertail-covert) or as maurus (as suggested by the width of the bill). As always, analysis of mitochondrial DNA will only give the genetic history of the mother, but both taxa are commonly distributed over huge areas in N Asia and there are some indications pointing to that hybridization may be less common than earlier believed. True or not, the likelihood of a purebred bird should exceed that of a hybrid by far.

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Ageing the bird: The primary coverts show a typical first-winter pattern with pale buffish edges, typically widening to a broader (and slightly diffusely set off) tip. In a folded wing, the broad pale tips almost blur into each other, hiding most of the darker parts of the feathers. In adult (2cy+) birds, the pale edges are typically whitish, narrower, more sharply set of against the black feather centre, and does not widen towards the tip. This character is applicable in most autumn individuals, but a few birds (especially females) may be harder to assess. Since this young bird have conducted a partial moult there are also moult contrasts to be found in the plumage. However, these contrasts are often hard to detect in photos, like here. Photo: Jarmo Pirhonen

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Sexing the bird: Rather straight forward, since black underwing-coverts are shown by males only. Photo: Jarmo Pirhonen

Another bird:

Another good looking bird was trapped at Haparanda-Sandskär Bird Observatory in the far north Baltic Sea, Sweden, a week ago. This bird, also a 1cy male, shows a similarly dark, but even more sturated, plumage. No dark markings in the uppertail-coverts were seen, and no measurement of the bill is available, but the overall impression suggest this one as a stejnegeri as well.


1cy male, Haparanda-Sandskär, Sweden, 2015-09-27, ringed and photographed by Magnus Karlefors & Ulf Öhman.


Svensson, L. 1992. Identification guide to European passerines. 4:th edition. Stockholm.

Hellström, M. & Norevik, G. 2014. The uppertail-covert pattern of ‘Stejneger’s Stonechat’. British Birds. 107:692-700.

A New Digital Guide to Ageing and Sexing of Birds

Magnus Hellström

“New species will be added, and bad photographs will be exchanged for better ones. But with new birds, new camera models and new light-systems pouring out each year, chances are that we will never reach a state where we will feel we have fully arrived. But that’s in the nature of the project. And part of its appeal.”


The short version:

Are you interested in the ageing and sexing of northern European birds?
Visit our new online guide:

The slightly longer version:

Every keen birdwatcher or ringer puts a lot of effort in ageing the birds in front of them. Why? A simple answer could be ‘because it’s fun’. Yes, I agree, it really is fun! But in a larger context the methods for ageing and sexing are also important tools that may tell us things about the state of our environment. Without such tools we would not know much about breeding success, winter survival, age- or sex-related differences in the timing of the migration or in the choice of wintering areas etc. The list could be made much longer, and by recording the age and sex of your birds, the importance of your notebook will grow significantly. And, it’s fun…!

Black Redstarts are a joy to every birder! Did you know that it is possible to age and sex some of the female type birds, even in field?

Black Redstarts are a joy to every birder! Did you know that it’s possible to sex a few of the female-type young birds, even in the field? The details are explained in the new guide, but in these two birds (that have conducted a more extensive post-juvenile moult than average), the tertials indicate both the age and the sex. The upper bird included all tertials in the moult, showing a good contrast with the still juvenile (and worn) secondaries, clearly visible in the small image to the right. The lower bird included the two inner tertials which contrasts to the still juvenile longer one. In this species, post-juvenile tertials (as well as the future post-breeding generations) can be used for sexing since males show silvery white edges to, at least one or two, of these feathers, while females don’t. Hence, a young female above, and a young male below.

At Ottenby Bird Observatory, SE Sweden, ringing of birds have been carried out since the end of World War II. A lot of knowledge has evolved from this activity, and ringers have been passing their increasing skills further to younger generations for decades now. During the last 20 years, the digital revolution have blessed us with (among other things) the internet, as well as the digital camera. Two great inventions without which the world would be a lot more boring. The ringers at Ottenby started to digitally document birds of different ages in the early 2000’s. In the beginning, the photos were terribly bad, but practise combined with technological achievments soon made us realize that the results may actually be very useful when training young and promising ringers. The idea of a ‘digiguide’ was born! And since the images were digital, why not put them on the internet in order to make the biggest possible use of them…


A 3cy+ Long-eard Owl, October. Birds showing moult contrast in the secondaries, and where the retained (worn) generation shows the adult type pattern, with similar barring to the adjecent fresh feathers, are possible to specify as 3cy+.

Today, more than a decade later, Ottenby B.O. sits on a hard disc drive containing close to 70.000 images of 3.900 individual hand-held birds of more than 230 species. Compiling these into an appropriate format, suitable for public viewing, is a huge task! But now we have started.

Since a couple of days ago, the doors have been open on the following address: Here you will find a user-friendly, practical and accurate guide to ageing and sexing of the birds passing through the Baltics (which are generally very similar to the species passing through British and other West European Bird Observatories). Initially, just above 30 species are included, but this number is planned to grow significantly during 2015.


Reed or Marsh? Or both? The guide will focus on ageing and sexing, but in a few cases we will also include some help for the species ID. In the photo shown here, a Marsh Warbler is seen to the left and a Reed Warbler to the right. Among other things, note the difference in coloration, proportions of the bills and the Reed Warblers tendency to show a slightly more contrasting eye-ring.

So, what are the high-lights? Well, as a ringer I would perhaps vote for pedagogical birds such as the 2cy Tree Pipits showing three different generations of coverts (remember to click each photo in order to view in large format). But as a birder with a Western European perspective I believe I would go for the beautiful images in the sexing chapter of autumn Red-breasted Flycatchers! Smashing birds! And how many of you have seen the plumage of the lower bird on that page? And don’t miss the Long-eared Owls. Or the Nightjars. Or the Snow Buntings…


A tristis-Chiffchaff in October. Can you find the moult contrast, proving the bird as a 1cy?

Ringers’ DigiGuide (yes, that’s what we chose to call it) is a living document. New species will be added, and bad photographs will be exchanged for better ones. But with new birds, new camera models and new light-systems pouring out each year, chances are that we never reach a state where we will feel we have fully arrived. But that’s in the nature of the project. And part of its appeal.


A beautiful Greenfinch! Adult or young? Male or female?

So, go a head and have a look around. The pages are not responsive, but the layout was chosen in order to work properly on smartphones and tablets as well. In that way we hope it will be of good use also in the field.


In many species the colour of the birds’ iris undergo a general development during the first year of living, basically turning warmer with age. Two autumn Thrush Nightingales shown here – a young to the left and an adult to the right.

Learning albicilla – Taiga Flycatcher variations

Chapter 17th in the new book covers 2 flycatcher species. Each chapter has a QR code which leads to a dedicated website with more material relevant to that chapter. Here then, an example of the kind of ‘extra’ stuff that might be found on the webpages which go with the book. Superb stuff from Magnus – will make you think differently about albicilla– we hope!


Magnus Hellström

“Albicilla is not always coloured in the cold greys hues that are shown in the literature ‒ quite frequently buffish tones are present in both breast/belly/flanks and in the edges of coverts and tertials. This is a good lesson to learn in the quest of finding one back home…” 

Adult (2cy+) male albicilla, Beidaihe; China, September.

Adult (2cy+) male albicilla, Beidaihe; China, September. Some adult males show traces of the red throat patch during autumn/winter. Photo: Magnus Hellström.

When the first extralimital Taiga Flycatcher for Europe was discovered here on Öland back in 1998 my first thoughts were something like this: 1: WOW! 2: Oh, they actually breed in Europe!? 3: How do we tell albicilla with certainty from (at the time conspecific) parva? 4: I’m sure it will prove to become a fully regular guest, probably with multiple annual records, in western Europe in the near future… My curiosity had been awakened, and shortly afterwards the Birding World paper by Cederroth, Johansson & Svensson (1999) drew the basic map for us readers. I made some own museum checks to get acquainted with the ID and prepared to find the second one for Öland. Today, 18 years after the first record, we are still trying to find number two… I was very wrong on the last point above – there are still only a handful of sightings of albicilla in western Europe, and I will still think WOW when the next one is found.

Adult (2cy+) female albicilla, Beidaihe, China. Photo: Magnus Hellström.

Adult (2cy+) female albicilla, Beidaihe, China, September. Photo: Magnus Hellström.

My first meeting with albicilla was some years later. My friends and I had been refused to pass the border into Mongolia (apparently it was some kind of holiday for the border staff as they choose to play poker instead of letting people through the gates), so we had to spend an unplanned extra day close by in the Chuya steppe in Russian Altai. We enjoyed breeding Isabelline Shrikes (as well as collurio-hybrids) in the shrubby high-altitude steppe when a small passerine appeared on a branch just in front of me. The black uppertail-coverts seemed to glow, and the ID was very unproblematic. Obviously it was a migrant on its way to the forests up in the north.

First-winter (1cy) albicilla, Beidaihe, China, September. Photo: Magnus Hellström.

First-winter (1cy) albicilla, Beidaihe, China, September. In this individual, note the rather warm edges to the greater coverts. Same goes for the edges of the tertials while the tips are purer greyish white. Photo: Magnus Hellström.

Since then I’ve had the opportunity to enjoy numerous meetings with albicilla, both in rather dense breeding populations and on spring and autumn migration. Spring males with their handsome red throats are beautiful sights, and the other plumages are always interesting to assess with reference to our breeding parva back home. In fact, what I initially thought as a plumage-type with rather low degree of variation, I now regard the ‘non-red-throated’-plumages as distinctly variable, and not seldom quite problematic. Albicilla is not always coloured in the cold greys hues that are shown in the literature ‒ quite frequently buffish tones are present in both breast/belly/flanks and in the edges of coverts and tertials. This is a good lesson to learn in the quest of finding one back home…

Albicilla is not always the cold grey bird that the fieldguides show us. Beidaihe, China, September/October. Photos: Marcus Danielsson and Gabriel Norevik.

Albicilla is not always the cold grey bird that the fieldguides show us. Beidaihe, China, September/October. Photos: Marcus Danielsson and Gabriel Norevik, Beidaihe Bird Observatory.

Other good lessons include the song and call: During early ringing mornings in NE China, while putting up the nets before sunrise, the soundscape always gives a good hint of what the morning is about to bring. The fast rattling calls from albicilla is often one of the dominating elements and, contra the Wren-like call from parva, my reaction when hearing albicilla is always ‘a weak Mistle Thrush’. The species is also a powerful singer, and the first time I run into the male song I actually did not realize it was a flycatcher until I got my eyes on it.

First-winter (1cy) albicilla, Beidaihe, China, October. Photo: Magnus Hellström.

First-winter (1cy) albicilla, Beidaihe, China, October. Photo: Magnus Hellström.

So, being a European breeding bird, why are they so uncommon in western Europe? Who knows, but with recent literature chances for new encounters grow considerably, and with the addition of Challenge Series: Autumn my hopes are that fewer albicilla will pass our bins undetected. Happy birding!

Citrine Wagtails ‒ how difficult can it be!?

Magnus Hellström

Sexing Citrine Wagtails, it sounds pretty easy, doesn’t it? And yes, typical and representative birds rarely causes any trouble in this respect: Smart looking males with bright and clean lemon head, ear-coverts and breast combined with a well-developed black nape collar signals their gender rather promptly. The same goes for most females showing a duller yellow front with darker olive-greyish crown and ear-coverts and a pale nape.

AGood looking 2cy male with clean yellow head and breast and black nape. Ageing supported by brownish and worn remiges and outer greater coverts. Russia, June. Photo: Magnus Hellström.

BRather typical female (probably adult due to apparently rather fresh and well-kept dark primaries and primary-coverts) showing greyish olive crown and ear-coverts. Russia, June. Photo: Magnus Hellström.

Life would be simple if the issue had stopped there but, rather stimulatingly, it doesn’t. More intermediately patterned individuals are sometimes seen and such birds often causes discussions in the birding community. This challenging problem is caused by the fact that some first summer (2cy) males shows less developed male characters while, conversely, some adult (3cy+) females attain a more colourful and male-like plumage than normally seen. Therefore, if seen under good conditions, there are means to collect further clues: change focus and start with ageing the bird. If 2cy, it is likely that the bird is a dull male, and if 3cy+ we have good reasons to assume it’s a bright female.

CDrab looking (and female-like) 2cy male that sang and held territory for a week. Aged as 2cy by still showing juvenile worn and bleached remiges, primary-coverts, alula and outer greater coverts. Sweden, May. Photo: Göran Bength.

The Citrine Wagtail – like its closest relatives – unfortunately shows a moult pattern where both the young and the adult birds replace their body contour feathers during winter (in a so-called partial pre-breeding moult). This moult does not include remiges, but it does include a number of greater coverts and tertials. This means that more or less all birds (regardless of age) in the spring will exhibit a moult contrast in the wing. Thus, in contrast to many other passerine species, the mere presence of a contrast is of no use for ageing. Instead, concentration should be directed to the parts of the wing that was not replaced during the winter, i.e. primaries and primary-coverts. Both 2cy and 3cy+ birds attained these feathers during the previous summer, but since juvenile feathers are of lower quality than subsequent generations, 2cy birds in the spring will show more worn and brownish primaries and primary-coverts than 3cy+. Mind, however, that also adult birds are getting quite worn by spring, but still usually retains a darker (dark greyish) feather colour. In other words, it is the degree of wear that has to be assessed.

DA rather difficult bird, but although the retained parts of the wing (some tertials, some greater coverts, alula and remiges) has become slightly worn they still give an adult appearance. In my opinion this is most likely a 3cy+ bird and therefore reasonably a female. Russia, June. Photo: Magnus Hellström.

As seen in the photos, Wagtails have a wing structure that often makes primaries and primary-coverts hard to study since they are covered by other feather tracts. This, of course, complicates the situation a bit, and it usually requires good observation conditions to be judged properly. However, the worn and brownish wing in many 2cy birds is often rather eye-catching, and it’s often easier to feel safe ‘nailing’ a 2cy bird than an adult one. In the end, this will probably lead to an over-representation of 2cy being aged (as proportionally more 3cy+ will be left un-aged). This is probably inevitable but can be useful to keep in mind.

EAnother one, giving a slightly sullied impression on crown and ear-coverts and completely lacking black in nape. Retained remiges gives a brownish and worn juvenile impression, and points towards 2cy. Being a 2cy the plumage would favor an ID as a male, and this was also supported by behavior as it defended territory on breeding ground. Mongolia, June. Photo: Magnus Hellström.

FOOTNOTE: If we aim for complete accuracy, the above statement that the presence of a contrast is of no use for ageing, deserves a deeper comment. Adult individuals undergo a complete moult after breeding, and after that the entire plumage is of the same generation. As mentioned above, the partial moult in the following winter creates a simple contrast among the coverts. Nothing strange so far. The juveniles, on the other hand, starts their life with a partial moult soon after fledging, and then, according to the same principles, receives a moult contrast before autumn migration. During winter they, again, conduct a partial moult. Sometimes (but not always) this winter moult include fewer coverts than the previous (post-juvenile) moult. Such a strategy results in a wing with two moult contrasts, since the outermost coverts are still juvenile, the central ones derived from the post-juvenile (summer) moult, and the innermost from the pre-breeding (winter) moult. Establishing three generations of coverts (two moult contrasts) is usually very difficult in field, but if we for some reason manage to do it, it is another good indication of a 2cy bird.

FA rather dark crowned but brightly yellow-faced bird with quite clean ear-coverts. The photo is slightly out of focus and the bird is wet from rain, but wear in primaries supports 3cy+ (and the bird appeared adult also in field). As adult this should be a safe female. Russia, June. Photo: Magnus Hellström.