An Okinawan thrush and the principles of zoogeography

by Greg Mayer

My Okinawan correspondent sends the following photograph of an apparently window-killed bird.

Window-killed thrush, Okinawa, Japan, 8 March 2016.

Window-killed thrush, Okinawa, Japan, 8 March 2016.

I thought immediately, “a thrush”, noting the similarity in bill, body and leg shape to that of the familiar North American Robin (Turdus migratorius). I was also immediately reminded of the justly famous opening passage in Alfred Russel Wallace’s Island Life, in which, comparing the birds of Britain and Japan, he finds them remarkably similar:

WHEN an Englishman travels by the nearest sea-route from Great Britain to Northern Japan he passes by countries very unlike his own, both in aspect and natural productions. The sunny isles of the Mediterranean, the sands and date-palms of Egypt, the arid rocks of Aden, the cocoa groves of Ceylon, the tiger-haunted jungles of Malacca and Singapore, the fertile plains and volcanic peaks of Luzon, the forest-clad mountains of Formosa, and the bare hills of China, pass successively in review; till after a circuitous voyage of thirteen thousand miles he finds himself at Hakodadi in Japan. He is now separated from his starting-point by the whole width of Europe and Northern Asia, by an almost endless succession of plains and mountains, arid deserts or icy plateaux, yet when he visits the interior of the country he sees so many familiar natural objects that he can hardly help fancying he is close to his home. He finds the woods and fields tenanted by tits, hedge-sparrows, wrens, wagtails, larks, redbreasts, thrushes, buntings, and house-sparrows, some absolutely identical with our own feathered friends, others so closely resembling them that it requires a practised ornithologist to tell the difference. If he is fond of insects he notices many butterflies and a host of beetles which, though on close examination they are found to be distinct from ours, are yet of the same general aspect, and seem just what might be expected in any part of Europe. There are also of course many birds and insects which are quite new and peculiar, but these are by no means so numerous or conspicuous as to remove the general impression of a wonderful resemblance between the productions of such remote islands as Britain and Yesso.

(Perhaps inspired by Wallace, the Japanese ornithologist Masa Hachisuka once published a comparative list of the birds of Britain and Japan.) Wallace went on to contrast the remarkable similarities between the birds of these two distant archipelagos with the differences one finds when crossing the narrow strait between Bali and Lombok:

In the Malay Archipelago there are two islands, named Bali and Lombok, each about as large as Corsica, and separated by a strait only fifteen miles wide at its narrowest part. Yet these islands differ far more from each other in their birds and quadrupeds than do England and Japan. The birds of the one are extremely unlike those of the other, the difference being such as to strike even the most ordinary observer. Bali has red and green woodpeckers, barbets, weaver-birds, and black-and-white magpie-robins, none of which are found in Lombok, where, however, we find screaming cockatoos and friar-birds, and the strange mound-building megapodes, which are all equally unknown in Bali. Many of the kingfishers, crowshrikes, and other birds, though of the same general form, are of very distinct species; and though a considerable number of birds are the same in both islands the difference is none the less remarkable—as proving that mere distance is one of the least important of the causes which have determined the likeness or unlikeness in the animals of different countries.

Wallace, of course—in this and many other works—went on to explicate what the important causes of these disparities were, not the least of which are the evolutionary and geological histories of the organisms and land masses. (In the case of Bali and Lombok, the key factor has turned out to be that Bali is on the Asian continental shelf, and thus has been in frequent dry-land contact with the continental fauna, while Lombok is off the shelf, and has received its fauna over water by occasional means of transport.)

Like Wallace’s traveling Englishman, I too was struck by the great familiarity to me of this bird from the opposite side of the world. But while it was certainly a thrush, and almost certainly in the genus Turdus, I could not identify the species. I don’t have a Japanese or East Asian bird field guide, but checking some pictures on the internet, it seems most similar to T. pallidus, a winter visitor to Okinawa. Our deceased friend seems too white below, so I leave its species undetermined. Perhaps some reader will be able to identify it.

Window-killed thrush, Okinawa, Japan, 8 March 2016.

Window-killed thrush, Okinawa, Japan, 8 March 2016.

In addition to being a familiarly thrush-like bird, it was also, sadly, in a familiar posture: dead outside a glass door. Window-killed Swainson’s thrushes (Catharus ustulatus) are an all too familiar sight here in southeastern Wisconsin. My correspondent added about this bird, “Such a shame to see a dead bird, because they’re actually kind of rare to see. I blame the cats and Habu.” Habu are any of various pit vipers found in the Ryukyu Islands, which I thought were not common. I’ve queried my correspondent as to the relative abundance of cats and habu.

Hachisuka, M.U. 1925. A Comparative Hand List of the Birds of Japan and the British Isles. Cambridge University Press, Cambridge. (paperback published 2015)

Wallace, A.R. 1892. Island Life. 2nd ed. Macmillan, London. (at Wallace Online)


  1. W.Benson
    Posted March 10, 2016 at 3:49 pm | Permalink

    It may be commented, too, that A. R. Wallace used the faunal differences between Bali and Lombok, the Wallace line, as evidence against Intelligent Design. Why, Wallace asked, should the two faunas, each living under essentially the same tropical climates, be so different across such a short distance if they were created to be harmonious and survive under the same conditions. Evolutionary biography explained what ID couldn’t.

  2. Posted March 10, 2016 at 3:52 pm | Permalink

    I’ve consulted HBW*, and it sure likes like T. pallidus to me; and there’s nothing else at all similar.

    I’d never quite noticed before what a huge genus Turdus is. It’s interesting that it covers a vast area of the world, almost everywhere with a lot of species co-occurring. Except in most of the U.S., where there’s one. Curious.

    *del Hoyo J., Elliott A., and Christie D. 2005. Handbook of the Birds of the World, v. 10: Cuckoo-shrikes to Thrushes. Lynx Editions, Barcelona.

    • Randy Schenck
      Posted March 10, 2016 at 5:24 pm | Permalink

      Checked a book we have – A field guide to the birds of Japan and the Pale Thrush (Turdus pallidus) is the closest I see. Common migrant to northern Japan and winter visitor to the rest.

  3. rickflick
    Posted March 10, 2016 at 4:16 pm | Permalink

    The quotes from Wallace are fascinating. He’s quite a naturalist-hero.

  4. John Harshman
    Posted March 10, 2016 at 4:47 pm | Permalink

    It’s not all that surprising to see similar avifaunas in Britain and Japan. They are, after all, at similar latitudes and with a continuous belt of land (save for a pair of narrow seas) connecting them. The northern Palaearctic is pretty similar across Europe and Asia. Is it any more than that? And of course a fair proportion of that fauna is Holarctic too.

  5. Posted March 10, 2016 at 7:20 pm | Permalink

    I’m guessing it is a pale thrush.

  6. Dionigi
    Posted March 10, 2016 at 7:24 pm | Permalink

    Can I suggest an immature black throated thrush Turdus rufficollis atrogularis as this is an Asian variety.

    • John Harshman
      Posted March 10, 2016 at 7:59 pm | Permalink

      That would be exceedingly far out of range, has a gray rather than brown back, and dark rather than yellow legs,

      • Dionigi
        Posted March 11, 2016 at 8:24 pm | Permalink

        From Wikipedia”The breeding range of the black-throated thrush extends from the extreme east of Europe to Western Siberia and north-west Mongolia. The wintering range extends from the Middle East, although uncommon in the Arabian Peninsula to eastern Burma. As a vagrant it has occurred in Japan, Thailand, and Taiwan as well as to most of Europe west of its normal range”
        The legs on the young are much lighter than on the mature bird. The tail is not black and the throat has a speckled rather than black bib

  7. Dower_House
    Posted March 11, 2016 at 1:01 am | Permalink

    To make it clear to dimwits like me, A R Wallace is the gentleman who co-presented the theory of evolution with Darwin, but with what appeared to me like skuilduggery and did not get equal acknowledgement.

    Interesting article.

    • Posted March 11, 2016 at 7:12 am | Permalink

      Russell seemed content for Darwin to have the recognition and priority — Darwin having formulated it earlier and developed it to a much greater degree than himself.

    • Jonathan Wallace
      Posted March 11, 2016 at 7:53 am | Permalink

      I don’t think there was any skullduggery involved. As far as I am aware both Darwin and Wallace behaved in an entirely gentlemanly and honorable way.

    • John Scanlon FCD
      Posted March 12, 2016 at 4:10 am | Permalink

      A.R. Wallace, extract from letter to Joseph Hooker, 6 October 1858

      [p. 166 in Burkhardt, F. and S. Smith, eds. The Correspondence of Charles Darwin. Vol. 7. 1858-1859. Cambridge: Cambridge University Press. (Darwin Correspondence Project website)]

      Allow me in the first place sincerely to thank yourself & Sir Charles Lyell for your kind offices on this occasion, & to assure you of the gratification afforded me both by the course you have pursued, & the favourable opinions of my essay which you have so kindly expressed. I cannot but consider myself a favoured party in this matter, because it has hitherto been too much the practice in cases of this sort to impute all the merit to the first discoverer of a new fact or a new theory, & little or none to any other party who may, quite independently, have arrived at the same result a few years or a few hours later.

  8. Tim Harris
    Posted March 11, 2016 at 4:54 am | Permalink

    Yes, surely Turdus pallidus – shirohara (white-belly) in Japanese – which is common in Tokyo (they come to our garden) and are common winter visitors in most of Honshu and further south. Pace a comment above, the latitudes of Japan and of Britain are very different: Tokyo is on roughly the same latitude as Tunis, and even the northern island of Hokkaido is to the south of Britain.

    • John Harshman
      Posted March 11, 2016 at 2:02 pm | Permalink

      OK, yeah. In my defense, Wallace was talking about northern Japan, which narrows the gap a bit, and while Britain gains the benefit of the Gulf Stream, Japan gets a cold current instead, making them more similar in climate.

      • Tim Harris
        Posted March 11, 2016 at 7:08 pm | Permalink

        You should try a Tokyo summer one day…

  9. Posted March 11, 2016 at 7:03 am | Permalink

    “I thought immediately, “a thrush”, noting the similarity in bill, body and leg shape to that of the familiar North American Robin”

    Me too — except I thought, “robin!”

  10. jaxkayaker
    Posted March 13, 2016 at 3:35 pm | Permalink

    Hi, Greg. I believe that “habu” is used as a synonym for the brown tree snake, Boiga irregularis (or Boiga dendrophila).

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