October 18, 2015

part seven:

Brown Shrike mixture

text by Abu & Axel

( links to previous posts: part 1, 2, 3, 4, 5, 68)

Nominate Brown Shrike Lanius cristatus cristatus is a common migrant throughout Mongolia and is a common breeding visitor in its prime habitat as well.

Male nominate Brown Shrike L. c. cristatus
Tsetserleg, Jun 2013. © A. Buchheim

Not far southeast of the border to China the nominate subspecies is replaced by another one, which can be recognized easily: L. c. lucionensis. Despite the close proximity of its breeding grounds to Mongolia, and the fact that it is also migrating to more southerly wintering grounds and hence could easily overshoot during spring migration, only two single Mongolian records of luscionensis-type birds have come to light so far, both in June (a good months for accidental spring overshoots) from the Gobi in southern Mongolia:

One was photographed by Axel (leading a Sunbird group together with James Lidster) in the sports stadium of Choibalsan city in South Gobi aimag (province) in June 2004:

Male luscionensis-type Brown Shrike, 14 Jun 2004
Choibalsan sport stadium, 14 Jun 2004. © A. Bräunlich

The second one was discovered by Axel and photographed by Paul Jones (see his excellent photographs from our trip here) in the Juulchin Gobi 1 Camp, South Gobi aimag in June 2012. This individual shows quite much brown reaching up onto the crown, but it has a strongly pronounced supercilium:

Male luscionensis-type Brown Shrike
27 Jun 2012, Juulchin Gobi 1 Camp. © P. Jones

Gombobaatar & Monks (2011) do not list lucionensis for Mongolia at all, but, besides the nominate subspecies, mention another subspecies: confusus.

The acceptance of L. c. confusus as a valid taxon has been doubted. It is poorly differentiated from nominate and is said to intergrade with it (Takagi 2008). Generally it would be very difficult to proof the intergrading of two almost similar taxa! Where should one draw the line?

According to Takagi (2008), confusus breeds from eastern Mongolia eastwards to Ussuriland. Lefranc & Worfolk (1997) also mention that confusus only differs slightly from nominate and list the Amur and Ussuri basins as well as Manchuria as its breeding grounds.

Prepared with this info, the Swamprunner team checked every Brown Shrike in the east. Only (!) in the Khalkh gol plantation we came across birds that differed from cristatus.

The first bird, a male, defended a poplar tree as its territory centre and he was observed to disappear in it frequently, giving rise to our suspicion that it may attend a nest (it must have been rather high up in the tree!). The bird was observed singing during most of the day. It was identified as Mongolia’s first “pure” lucionensis and is portrayed in the following three photos.

Singing male lucionensis Brown Shrike
Khalkh gol plantation, Jun 2014 © A. Buchheim

Singing male lucionensis Brown Shrike
Khalkh gol plantation, Jun 2014 © M. Putze

Male lucionensis Brown Shrike
Khalkh gol plantation, Jun 2014 © M. Putze

Note that it shows no brown on its crown which is pale grey instead. Its entire upperparts (apart from the crown) appeared rather dull brown lacking the vivid red brown colouration of the nominate subspecies. We never saw the partner of this male and she was supposedly sitting tight on her eggs. The next three photos show nominate Brown Shrikes for comparison. Regardless of their sex these are all reddish brown from crown to tail.

nominate Brown Shrike
Buir Nuur, Jun 2014 © T. Langenberg

nominate Brown Shrike
Khalkh gol plantation, Jun 2014 © T. Langenberg

nominate Brown Shrike
Khalkh gol plantation, Jun 2014 © T. Langenberg

We also saw two Brown Shrikes which showed intermediate characteristics between cristatus and lucionensis. They neither had clear reddish-brown crowns nor were their crowns all grey (cf the two birds from the South Gobi from June 2004 and June 2012, depicted above). To us it seems plausible to call them intergrades between these subspecies and we would like to ask for comments on the identity of these two puzzling individuals. Are these two actually belonging to confusus? And is it possible that the race confusus is actually a hybrid swarm of lucionensis and cristatus? If so, than indeed confusus would be an invalid taxon.

Brown Shrike, first intermediate individual
Khalkh gol plantation, Jun 2014 © A. Buchheim

Brown Shrike, second intermediate individual
Khalkh gol plantation, Jun 2014 © A. Buchheim

Literature cited

Gombobaatar, S. & Monks, E.M., compilers (2011). Mongolian Red List of Birds. Regional Red List Series Vol. 7. Zoological Society of London, National University of Mongolia & Mongolian Ornithological Society, London & Ulaanbaatar.

Lefranc, N. & Worfolk, T. (1997). Shrikes: a Guide to the Shrikes of the World. Pica Press, Robertsbridge, UK.

Takagi, M. (2008). Brown Shrike Lanius cristatus. Pp. 777-778 in: del Hoyo, J, Elliott, A. & Christie, D.A. eds. Handbook of the Birds of the World. Vol 13. Penduline-tits to Shrikes. Lynx Edicions, Barcelona.

There are also two very interesting contributions by Nial Moores, discussing the identification of Brown Shrike taxa on BirdsKorea:

Brown Shrike Lanius cristatus appearance and variability of individuals seen on migration in South Korea (from 2004)

Brown Shrikes and the Annual Thorny Identification Challenge! (from 2015)