Tetrapod Zoology

A challenge for you (albeit another easy one): what species, and what activity, do these photos represent? I’ll give you a few clues…

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On second thoughts, I won’t. Well, all I’ll say is that the photos were taken in the New Forest in southern England and show one of the region’s most famous birds. Tell me more!

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Photos by Tara Dempsey, used with permission.

UPDATE (added 9th August 2010): Many thanks to all of you for your guesses. Many of you got it right, or mostly right. What we’re looking at here is a juvenile Dartford warbler Sylvia undata, shown impaled on gorse spines. Admittedly, you definitely have to know Dartford warblers in order to recognise the corpse: giveways include the yellowish legs, the greyish-buff flanks, the grey upperparts, the small size (only obvious if you know how big gorse spines are), and the association with gorse. The long tail feathers are missing. The head is not missing; it’s merely tucked down and mostly out of view.

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As correctly guessed by many of you, the bird was captured and cached by a shrike. We know this because the capture and caching was observed. The photo is a recent one (though, sorry, I hadn’t said this): this means that Red-backed shrike Lanius collurio can be ruled out as the cache-maker, as this species became extinct in England round about 1988 (or maybe a few years later). The photo was also taken in the winter, meaning that any shrike that cached the warbler must be either a resident or a winter visitor. And the Great grey shrike L. excubitor is (in the UK, at least) well known for being a winter visitor of the New Forest (it’s the only shrike present in southern England during the winter*). Individuals are usually present from October until April or so: the number of birds that visit the forest varies from year to year, but it’s something like 6-8. So, we’re looking at a juvenile Dartford warbler cached by a Great grey shrike [the adjacent photo of a Great grey shrike (with Striped field mouse Apodemus agrarius) – taken in Poland, not Britain – is by Marek Szczepanek, from wikipedia].

* Though Brown shrikes L. cristatus have, in recent years, been seen in Britain during the winter.

Thanks again to Tara for providing the photos and the information. I’ve seen shrikes pursuing passerines, but I haven’t seen a successful capture, nor have I yet seen a shrike cache. I hope that, one day, I will.

Comments

  1. #1 Richard Hing
    August 6, 2010

    A red-backed shrike’s kill cache?

  2. #2 Sordes
    August 6, 2010

    Looks like a shrike´s work. Possibly a Lanius excubitor?

  3. #3 Robert
    August 6, 2010

    I agree with Richard Hing and Sordes.

    The Shrike hangs its prey on plants, hence its other, common name – the Butcher Bird….

  4. #4 Neil
    August 6, 2010

    Darn Hing beats me too it again. We’ll ahve to sort a trip this winter to go look for it.

  5. #5 Bill
    August 6, 2010

    “…SHOW one of the region’s most famous birds”? So you mean the impaled one? A tailless Dartford warbler become the victim of a red-backed shrike

  6. #6 Brian
    August 6, 2010

    I think it’s a Little Bittern. As for what it’s doing: It’s been impaled, it seems. A shrike might have done it, though I wonder if a tiny heron wouldn’t be a tad too big for a shrike. I suspect it’s the cache of something else, though I can’t say what.

  7. #7 tai haku
    August 6, 2010

    I’ll agree with Bill.

  8. #8 BJN
    August 6, 2010

    The inspiration for the spikey impaling creature that inhabits the Hyperion universe science fiction series by Dan Simmons:

    “The Shrike stands roughly three meters in height and is described as being composed of razorwire, thorns, blades, and cutting edges, having fingers like scalpels and long, curved toe blades. It is basically a gigantic, bladed killing machine.

    The Shrike weighs over a ton, though it is apparently capable of modifying its density as it sees fit.

    Though metallic in appearance (“quicksilver over chrome”), the Shrike is also described as an ‘organic’ machine, humanoid in a general way, but with four ‘oddly jointed’ arms and intense, multi-faceted ruby eyes.”

    BTW, shrikes impale their prey because they don’t have talons to hold prey while pulling it apart like raptors do.

  9. #9 Pedro Cardia
    August 6, 2010

    Hi,

    The leg colour is ok for a Sylvia undata. The light brown colour of the bird hints that it is (was) a juvenile, which when leaving the nest are much shorter tailled than the adults, though it appears as the tail fethers are indeed missing (as the head too…). I’m unsure if the bird’s head is really missing or simply not visible due to being turned towards its left side. Are Lanius collurio breeding again in Britain? If not, could the culprit be an early arriving Lanius excubitor (which should be a winter visitor to Britain if BWP is to be trusted)?

  10. #10 Jake
    August 6, 2010

    Little Bittern (as mentioned by Brian) looks quite supportable, particularly given the feet, bill, body structure, and coloration (assuming the upperwing coverts are shaded). That prey item would be on the large size, but definitely not unreasonable, for Lanius excubitor. I once encountered a Western Meadowlark (Sturnella neglecta: 16–26 cm length, 89–115 g) impaled on a fence by a shrike (L. excubitor or L. ludovicianus) near other typical items like grasshoppers. In a quick browse of the L. excubitor account from Cornell they mention published accounts of preying on and caching many largish birds, including Columba livia (~340 g!).

  11. #11 David Kelly
    August 6, 2010

    Red-backed Shrike still occasionally breeds in Britain, most often in Scotland, but this is not recorded every year. Darren has not said that the picture is recent but how about it is a fledgeling Dartford Warbler which has impaled itself on a gorse thorn. Given the rarity of breeding Shrikes in Britain that’s a far more likely answer.

  12. #12 Diego
    August 6, 2010

    Dang, a bittern does seem kind of big for a shrike’s prey! I can’t think of a better explanation yet though.

  13. #13 Mo Hassan
    August 7, 2010

    Pretty sure it’s not a little bittern, as it’s not really known as a New Forest speciality… I will go for Dartford warbler, as a food store cached by a red-backed shrike on a gorse bush. That all seems pretty New Forest-y.

  14. #14 Stu of the Peak
    August 7, 2010

    I would agree the bird was more likely a victim of a Great Grey Shrike (Lanius excubitor). As for the chap himself, cast my lot with the Dartford Warbler too.

  15. #15 Jerzy
    August 7, 2010

    This fledging songbird – maybe meadow pipit – could be shrike’s prey.
    Or it could casually impale itself on a thorn, which sometimes happens. Or sometimes birds die caught by burdock or similar plant. Strange, there are even reports of birds caught for ringing, living with a broken thorn stuck into it.

  16. #16 Jerzy
    August 7, 2010

    PS indeed it looks more like Dartford Warbler minus tail.

  17. #17 AnJaCo
    August 7, 2010

    Either the work of a Shrike as mentioned or a nearly fledged young bird that fell from a nest above and accidentally impaled itself.

    [Dang, Jerzy beat me to it…]

  18. #18 Red
    August 7, 2010

    I would agree that it’s likely to be a Great Grey Shrike’s kill.

  19. #19 Red
    August 7, 2010

    I would agree that it’s likely to be a Great Grey Shrike’s kill.

  20. #20 kris
    August 8, 2010

    Wow! I’ve seen shrikes and their caches, but there was never anything bigger than insects in there. I didn’t know they can take other birds — but apparently they do.

    Also, since neither of the shown participants are a nightingale or a rosebush, I can rule out the Oscar Wilde story as an explanation.

  21. #21 pomposa
    August 8, 2010

    re. Wilde
    “The Dartford Warbler and the Gorse” just doesn’t have the same ring to it.

  22. #22 John Harshman
    August 8, 2010

    You might imagine that an ornithologist would be good at this sort of thing. You would imagine wrong. But I looked up Dartford Warblers, and that looks good to me. Seeing a bittern takes more imagination than I can summon.

  23. #23 Mark Lees
    August 9, 2010

    I think this is a Dartford Warbler – probably young.

    As for what happened to it, well it could be a shrike’s cache, but shrikes aren’t that common in the UK these days, though great grey and red-backed do occur. When I have seen red-backed shrike’s their prey is more focused on large insects, though small birds are potentially on the menu, and a fledgling would be ‘easy meat’.

    While it could be a shrike’s cache, I can see nothing from the photo to indicate that it isn’t just a young Darford Warbler that impaled itself on a gorse bush. Given that Darford warbler is of fairly restricted distribution in the UK and is expanding its range (it has started colonising parts of South Wales within the last decade) I guess the pointless loss of one is alsways smehting to be sad over.

  24. #24 Dartian
    August 9, 2010

    how about it is a fledgeling Dartford Warbler which has impaled itself on a gorse thorn. Given the rarity of breeding Shrikes in Britain that’s a far more likely answer.

    I think David’s nailed it. Cunning fellow that he is, Darren surely anticipated that people would go guessing it’s a shrike kill, while in reality that’s probably just one more item from his ‘animals killed by weird accidents’-file.

    Regarding large/unusual shrike prey items, by the way: There is a report from Germany of a stoat Mustela erminea being the victim of a great grey shrike Lanius excubitor. Grünwald (1984) found – and photographed – the mummified remains of the stoat impaled in a shrike’s larder. The stoat was a small female and probably not yet fully adult, and judging by the relatively intact state of the carcass the shrike seemed to have had problems with feeding on it. Apparently, prey items of this size are no longer optimal for the shrike, not to mention that attacking a stoat can’t be risk-free for such a relatively small bird. (However, Grünwald also mentioned other recorded observations of apparently successful predation attempts on stoats and weasels Mustela nivalis by great grey shrikes in that area.)

    Reference:

    Grünwald H. 1984. Weitere Mitteilungen zur Überwinterung des Raubwürgers (Lanius excubitor) im Sauerland (1982/83 und 1983/84). Charadrius 20, 36-44.

  25. #25 Darren Naish
    August 9, 2010

    Thanks to all for comments. Answers now provided in the text of the article.

  26. #26 Jerzy
    August 10, 2010

    Dartford Warbler and Red-backed Shrike are both uncommon in England, so pretty unusual to see one killing another. If it was in eg. South France the matter would be clear!

  27. #27 Jerzy
    August 10, 2010

    A friend of mine saw red-backed shrike hunting and impaling a whole brood of hawfinches – and not to eat it. It seems that much of the cached food is not eaten, or could it be that second choice food is impaled and shrike looks for something better?

    (BTW – this matter was probably answered, but i don’thave access to the primary literature now).

  28. #28 Darren Naish
    August 10, 2010

    Caching prey is sexy. See…

    Yosef, R. & Pinshow, B. 1989. Cache size in shrikes influences female mate choice and reproductive success. The Auk 106, 418-421.

  29. #29 Jerzy
    August 10, 2010

    I just imagine cavemen having all the biggest mammoth carcasses around their camp to impress women 😉

  30. #30 Nathan Myers
    August 10, 2010

    Have shrikes been seen eating grubs that grow in their cached catch?

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