Bohemian Rhapsody

text & photos by ABu

1. Can you identify this bird?

UB, October 2014

2. What about this one? Any idea?

UB, October 2014

3. Another bird, another try!

UB, October 2014

OK, OK, I must admit that it is not really challenging to identify all the birds above as Bohemian Waxwings Bombycilla garrulus. But what about sexing and aging them?

Even for the most basic science projects, like counting birds, one needs to identify the birds that got to be counted. More sophisticated scientific approaches surely could and would largely benefit from more elevated skills. It is possible to monitor the breeding success of species that breed in area with low observation pressure. All high arctic geese species are monitored on their wintering grounds, because it is easy to tell adults from juveniles. By doing so the data collected become also very valuable for conservationists. Aging and sexing is not possible in many songbirds but in Bohemian Waxwing it is straightforward.

All the information about sexing and aging of Bohemian Waxwing can be found in various publications (see below) and I simply have compiled this info here. The pictures show the Asian subspecies centralasiae which does not differ much from nominate. They had been taken on 25 October 2014 below Songino Khairkhan Uul, Ulaanbaatar, where c. 250 waxwings were busily foraging in the trees.

So let’s start with task of aging. All you need to do is checking the primary tips. There are 6 to 7 exposed primary tips to be checked. Juvenile primaries, which are moulted about one year after fledging, differ obviously from older generations of primaries. If the bird in question has the yellow fringe at the tip only on the outer web then it still has juvenile primaries and hence is in its first winter. On the folded wing these pale yellow streaks seemingly fuse to a single line. Adults show also some yellow along the feather tip on the inner web which creates a clear yellow angle. This is most pronounced in males. Females usually show only very weak yellow fringes on the inner web which can be completely lacking on some primaries. But even so, there never will be just a single line down the primaries. Furthermore the yellow is yellower in adults, especially on the inner 3 to 4 of the exposed primaries.

Once aging is completed one could continue with sexing. For sexing you should check all of the several field marks to reach the safe side. In general, and this applies to all ages, males show a wider yellow tip to the tail feathers. Unfortunately there is a little overlap making this feature not totally foolproof. This means that only extremes can be sexed by using solely this character.

Next to be controlled is the size and number of the waxy tips of the tertials (and some secondaries). Please note, that some adults, and it is again more often seen in males, can show these waxy tips also to the tail feathers. Adults have not only the bigger waxy tips but also more (on average only, so be careful with this as well!) and males have not only bigger ones but also more compared to females of the same age. Because of the overlap in numbers again only extreme examples can be sexed. In young birds those with no or only a single waxy tip are female and those with 8 are male. In adults males have 6 to 8 and females 5 to 7. In field it will be impossible to count the waxy tips accurately enough, so forget it and take good pictures and count the waxy tips on your screen.

Although some think the final character to be checked is not an easy one to pin down in the field, it can be checked on photographs. The lower border of the throat-patch is sharply demarcated in males and is diffuse in females.

In the field it will look like this:

Adult male

Pictures 4 to 6 show the same adult male. Note that this one has only 5 but quite large waxy tips (they can break off! On the other wing it has 7 waxy tips) but it shows both, a very broad yellow tail tip and very broad angles to the primary tips (picture 5). Also, its throat-patch shows a sharp border (picture 6).

The second adult male, featured in pictures 7 to 9, also has a reduced number of waxy tips. But the remaining ones are quite large (long). It has angles to the tips of the primaries, a well defined throat-patch (picture 9) but this one’s tail band is not that broad (picture 8).

4. Adult male Bohemian Waxwing

UB, October 2014

5. Details of tail and wing of the bird in picture 4

UB, October 2014

6. Head of the same bird as in pictures 4 and 5,

UB, October 2014

7. Adult male Bohemian Waxwing

UB, October 2014

8. Details of tail and wing of the bird in picture 7

UB, October 2014

9. Head of the same bird as in pictures 7 and 8,

UB, October 2014

Adult female

Adult females are next. The one in pictures 10 to 12 can easily be aged by its angles on the primary tips (but not on the two longest primaries!). However, they are quite narrow as is the yellow on tail tip. Its 6 waxy tips are rather large (picture 11). In picture 2 it can just be seen that the border of the throat-patch is diffuse.

Another adult female is shown in pictures 13 and 14. Note the narrow angles and its narrow yellow tail-band. It has also 6 rather long waxy tips.

10. Adult female  Bohemian Waxwing

UB, October 2014

11. Details of tail and wing of the bird in picture 10

UB, October 2014

12. Head of the same bird as in pictures 10 and 11,

UB, October 2014

13. Adult female Bohemian Waxwing

UB, October 2014

14. Details of tail and wing of the bird in picture 13

UB, October 2014

First winter male

In the following 4 pictures (13 to 16) you can see how easy it can be if you can look closely enough.

Note that there are no angles on the primaries. It has a very broad yellow tail-band, 6 rather large for a bird of this age waxy tips (picture 14) and shows a very well demarcated throat-patch (pictures 15 and 16).

15. First winter male Bohemian Waxwing

UB, October 2014

Details of tail and wing of the bird in picture 15

16. UB, October 2014

17. Head of the same bird as in pictures 15 and 16,

UB, October 2014

18. Another view of the head of the same bird as in pics 15 to 17,

UB, October 2014

First winter female

The first winter female in the pictures 19 to 21 can be aged by the lack of the primary angles and sexed by the narrow tail band and its diffuse border to the throat-patch.

19. First winter female Bohemian Waxwing

UB, October 2014

20. Details of tail and wing of the bird in picture 19

UB, October 2014

21. Head of the same bird as in pictures 19 and 20,

UB, October 2014

That’s it. Not quite. Test yourself with the following 12 pictures.

Bohemian Waxwing (first winter female)

UB, October 2014

Bohemian Waxwing (adult male)

UB, October 2014

Bohemian Waxwing (adult female)

UB, October 2014

Bohemian Waxwing

(first winter female, aging not possible from this picture)

UB, October 2014

Bohemian Waxwing

(adult male, same as in pictures 4 to 6)

UB, October 2014

Bohemian Waxwing (first winter female)

UB, October 2014

Bohemian Waxwing (adult female)

UB, October 2014

Bohemian Waxwing (adult female)

UB, October 2014

Bohemian Waxwing

(first winter female, same as in the next picture)

UB, October 2014

Bohemian Waxwing

(first winter female, same as in the picture above)

UB, October 2014

Bohemian Waxwing

(first winter male, same as in the next picture)

UB, October 2014

Bohemian Waxwing

(first winter male, same as in the picture above)

UB, October 2014

First three photos, solution:

Pictures 1 and 2 show an adult male.
Picture 3 shows a first winter male.


Recommended reading

Svensson, L. 1992: Identification Guide to European Passerines. Stockholm.

Svensson, L., K. Mullarney & D. Zetterström 2009: Collins Bird Guide. London.

Graf, O. & R. Martin 2005: Alters- und Geschlechtskennzeichen des Seidenschwanzes Bombycilla garrulus. Limicola 19: 233-239.


I hope that this post will help you in the field.
So go after them!