Far Eastern / Japanese Larks: a Temporary Taxonomic Treatment!

Nial Moores, August 8th 2012

A useful discussion on skylarks in Japan was started this week on the Kantori Listserver (a Yahoo group, focused on birding in Japan). Joseph Morlan wrote that “Other than the reported occurrence in Sakhalin and the Southern Kuriles, japonica has not been recorded outside of Japan as far as I know”. Following a response by Richard Klim (which included a link to the Birds Korea 2009 Checklist), Joseph Morlan (with good reason!) questioned our taxonomic decisions, and suggested that the ID criteria on our website might also be in need of further testing.

Richard Klim also added the following:

Zink et al. (2008) identifies deeply divergent western and eastern clades representing “phylogenetic, and possibly biological, species” – but with a slightly different division: A. arvensis ‘Skylark‘ (including at least dulcivox, and presumably all Western Palearctic sspp) and A. pekinensis ‘Pekin Skylark‘ (including at least kiborti, intermedia, lonnbergi).  Unfortunately, japonica wasn’t sampled. See www.springerlink.com/content/hx0h91103t281181

Rather than post at length to the Kantori Listserver, I hope it will be rather more useful to post a detailed response here, and to invite comments.

 
Our Identification Note
 

The identification note on the Birds Korea website (here) was written in 2003, and is in need of revision.

Many of the criteria were first developed when I lived in Japan (1990-1998). Japanese Lark was common throughout the year close to where I lived in Fukuoka, Kyushu. I saw Eurasian Skylark less often – usually mixed in with flocks of Japanese Lark on migration e.g. on Hegura and Ainoshima or at Imazu, or in small numbers in winter from Ishikawa south to Fukuoka prefectures.  They were usually not too difficult to pick out in mixed groups – by the naked eye or ear. Scope views suggested that the plumage of Japanese Lark was consistently more rust-saturated. They also lacked pure white on the secondary trail, and showed a much clearer Pectoral Sandpiper- like breast band underlain by warm buff.  Eurasian Skylark by contrast were generally larger and much paler overall. These differences seemed consistent with differences several of us could also see in many skylark observed in the Republic of Korea (ROK) during the 1990s and early 2000s.

 
Recognition of Japanese Lark as a Full Species
 

Following Moores(2003), Birds Korea decided to recognise Alauda japonica (Hibari in Japanese, and Japanese Lark / Japanese Skylark / Far Eastern Skylark in English) as specifically distinct from A. arvensis (O-hibari in Japanese, and Eurasian Skylark in English).

This decision was based on:

1) Usually quite obvious differences in the field between “Hibari” (Japanese Lark) and “O-hibari” (Eurasian Skylark);

2) BirdLife International’s treatment of Japanese Skylark as a full species: see here;

3) Comments from some expert ornithologists who consider Japanese Lark to be a summer visitor to northern Russia, where it apparently breeds sympatrically with Eurasian Skylark (possibly of subspecies pekinensis?); and also from some experienced observers in China, who suspected that they were seeing Japanese Lark in winter;

4) Plumage and structural differences between some breeding and some migratory skylarks sensu lato in the ROK – and by comments in Austin (1948).

Please note, however, that our recognition of Japanese Lark as a full species is still not widely accepted by others in the ROK (or elsewhere). Our checklist aims to follow Gill & Donsker (2012) (and versions thereof) unless we consider that there is strong evidence to the contrary. Gill & Donsker (2012) does not recognise Japanese Lark. Our present taxonomic treatment therefore remains open to major revision when / if better information comes to light.

 
Skylarks in the ROK
 

In the ROK, birds that looked like Japanese Lark (“Hibari-types”) were not uncommon in the late 1990s/early 2000s, both wintering and breeding locally, especially in the south. Eurasian Skylark was rather commoner, especially northward and in winter, when flocks of 50-100 were widespread (all skylarks, sensu lato, have declined greatly in recent years).  These larger larks lacked strong rusty tones in the mantle and on the ear coverts, and although they showed huge variation in plumage tones and bill structure, they consistently shared clean white secondary trails and gave longer, more melodic call notes than the Hibari-types.  Many therefore looked and sounded similar to O-hibari in Japan.

I also found several pairs of large, pale skylarks (first in May 1998 and 1999) that were breeding close to areas where smaller, more rusty-toned Hibari-types were breeding. In addition to differences in plumage (as in winter), there were also obvious differences in some of the song-phrases and in the call-notes, an apparent difference in the extent of tail fanning shown by singing birds, and subtle differences in behaviour and nest site habitat.  It seems likely that such near-sympatric breeding was not a recent phenomenon: Austin (1948: 171) observed that in Korea some people claimed “two distinct subspecies (of skylark were) breeding in the same area!”

Sympatric or near-sympatric breeding (within a few km of each other) of two skylark taxa in our opinion supports recognition of Korean Hibari-type birds as Japanese Lark, and also supports the splitting of Japanese Lark from Eurasian Skylark at the species level.  It also suggests that BirdLife’s range map of “Japanese Skylark” needs modification – and that there is a need for a better English name for A. japonica than Japanese Lark!  This is especially so if observers in Russia and China are also correct in their assumptions.  The difficulty in finding a decent name helps explain some of the inconsistencies in English nomenclature on our websites. Until recently, the name Far Eastern Skylark seemed to be a good fit for a species with such a potentially wide breeding and non-breeding Far Eastern distribution – but since Zink et al. (2008) this name too might be a tad confusing…

 
Why include intermedia in Japanese Lark?
 

Austin (1948) stated that the 1942 Japanese Hand-List of birds gives “A. a . quelpartae as the breeding race in Korea, with pekinensis and lonnbergi occurring as migrants or winter visitors, thus largely following Yamashina’s treatment of the species…” (p. 171). Quelpartae is based on the old name for Jeju Island – (Quelpart) where Japanese Lark is nowadays common and perhaps largely resident.   Austin collected five (paleish) birds that he described as quelpartae not on Jeju (which he never visited), but instead on the mainland near Seoul in April. He considered them to be summer visitors there. In general, Austin was intolerant of people trying to name new subspecies without strong evidence. He therefore rejected most of the subspecies described by Momiyama – the author who apparently described quelpartae from his time on Jeju. Austin and others’ description of Korean skylarks as quelpartae, however, makes explicit that they considered skylarks in Korea to be different from lonnbergi, pekinensis and also from japonica breeding in Japan. We therefore believe that the quelpartae of Austin does not refer to japonica.

Based on observations this century on ROK offshore islands, Japanese Lark (again based on ID features given in our online article) are early spring migrants (mostly in late March-mid April – the same period in which Austin found quelpartae near Seoul). They are also late autumn migrants on the same islands, when they often occur with Eurasian Skylark. Many of these migratory Japanese Lark seem paler and less distinctive than those Japanese Lark that breed on Jeju and in the south-east (though I do not believe that I have had any chance to compare them directly: perhaps some birders on Jeju have?).  On the dates and their subtle differences from Japanese japonica and from Eurasian Skylark in the ROK, such birds seem to provide the best match for Austin’s quelpartae.

Based on general migration patterns of a large number of species recorded on offshore islands in the Yellow Sea, this population of Japanese Lark is also presumed to migrate to China in winter, and to return through Korea in the spring, likely breeding in central Korea northward. This taxon therefore seems a potentially decent fit for the taxon that observers have recorded breeding in northernRussia and which others suspect winters in central-southern China.

If this more migratory population is not part of japonica sensu stricto as Austin and others stated, but is still part of Japanese Lark, then what name should be used for it? Quelpartae might fit – but this also might be an odd name to restore – especially as, on present knowledge, it probably is not actually found on “Quelpart” (Jeju)!  It would of course be most helpful to learn what happened to the type specimen of quelpartae, and to the specimens that Austin collected…

For now it appears that “quelpartae” is a taxon that – if the assumptions listed here are correct –overlaps in range with Eurasian Skylark in some areas (including the ROK and apparently northern Russia) while in other areas its range perhaps lies between nominate Alauda japonica and A. (arvensis) pekinensis.

To this background, a few ornithologists (including in the ROK) have stated that intermedia is the regular breeding skylark in Korea. This is the assumption too of Gill & Donsker (2012), who give the range of intermedia as “nc Siberia to ne China and Korea” and also of the Internet Bird Collection (see here) which provides a little more geographical detail: “breeds NC Siberia from basin of R Vilyuy and middle R Lena E to R Kolyma basin, S to NE China and Korea.”  Certainly, some images of Russian intermedia that I was sent some years ago also seemed to match what we were seeing here.

The published presence of intermedia in Korea; the presumed absence of japonica from most of the ROK (Gill & Donsker 2012 give the range of japonica as “s Sakhalin I., s Kuril Is., Japan and Ryukyu Is.” ); and the differences between near-sympatric breeding birds here in the ROK led to the decision to include intermedia in Japanese Lark.

 
Skylarks on Jeju and in southeast Korea
 

Southernmost Korea (Jeju, and the south coast from Mokpo to Busan north to Pohang) is the mildest part of the Korean Peninsula. This subregion has broadleaved evergreen vegetation as well as warm temperate vegetation, and shares breeding species like Japanese White-eye Zosterops japonicus japonicus and Japanese Bush Warbler Cettia diphone cantans with Japan. The Japanese Lark on Jeju and in the SE (to my eyes and ears) seem identical to birds that I used to see in Kyushu – but subtly different to the rather paler birds seen nearer to Seoul and on some offshore islands during migration.

These small differences might be a product of local variation (or even imagination!). They also remain unsupported by genetic analysis, or detailed published studies.  Following BirdLife International’s commentary (and now range-map), we therefore made the reluctant decision in the 2009 Checklist to omit nominate japonica as a regular Korean taxon. However, it seems likely that these southern-nesting skylarks are indeed nominate japonica – occupying the wettest and warmest part of the Korean Peninsula. Note that nominate japonica is listed as breeding on Tsushima (Teima Island) by Brazil (1991), and that this island is at its closest only 50km south of the ROK south coast.

In the absence of better information, those compiling their own checklists seem to have several possible options:

1) To conclude that all of these skylarks are a mess and are best treated together as Eurasian Skylark;

2) To include Japanese Lark in Oriental Lark A. gulgula (latter considered, however, to be largely resident in much warmer climes, and also to show consistent differences from both Japanese Lark and Eurasian Skylark);

3) And the one we decided on – which for now seems to be the most appropriate and elegant – to recognise two subspecies of Japanese Lark. These are the rustier, more compact form (nominate japonica) which is found in much of Japan (and most probably in SE/SW Korea); and the rather more migratory paler form (intermedia).

We consider that the two larger forms (pekinensis and lonnbergi) as previously recorded by Austin and others in the ROK, are within Eurasian Skylark A. arvensis, or better, within the “Pekin Skylark” of Zink et al. (2008), presumably along with several other subspecies yet to be recorded in Korea.  And the largely resident lark with its own distinctive call and more strongly buffy secondary trail (found further south in southern China) remains as Oriental Skylark A. gulgula.

Personally, I do not know anybody who up to now has had the support, time and expertise to do detailed research on these birds – in Russia, Japan, Korea and in China.  Does anyone know of any such research?  Happily, it seems from emails that a certain Professor Alström might at least been considering the challenge!

Thanks in advance for your comments…

 

References

Austin, O. L., Jr 1948. The birds of Korea. Bulletin of the Museum of Comparative Zoology,

Harvard University 101: 1-301.

Brazil, M. 1991. The Birds of Japan. Published by Helm.

Gill, F and D Donsker (Eds). 2012. IOC World Bird List (v 3.1)

Moores, N. 2003. Identification of Japanese Lark. Online identification article, posted by Birds Korea in March 2003; accessed in August 2012 at: www.birdskorea.org/Birds/Identification/ID_Notes/BK-ID-Japanese-Lark.shtml

Zink, R., Pavlova, A., Drovetski, S. & S. Rohwer. 2008. Mitochondrial phylogeographies of five widespread Eurasian bird species. Journal of Ornithology, Vol. 149, 3, 399-413. Accessed, June 2010 at: http://www.springerlink.com/content/hx0h91103t281181/