Tetrapod Zoology

It’s well known that herons are gluttonous birds that will catch and eat (or try to eat) pretty much any animal within the right size range. Everyone knows that herons eat fish, but they also eat frogs, snakes, small mammals (including rodents and rabbits), and birds including doves, grebes and ducklings. We previously looked at a rabbit-eating Great grey heron Ardea cinerea here. I’m actually intending to talk about herons and their feeding behaviour at length at some stage; not today though.

i-b5620e3535be56f925769cee88584e60-Wolf-&-Jones-1989_heron-vs-lamprey-2.jpg


Over-enthusiastic attempts to swallow large prey items have resulted in various recorded heron deaths: Langdale (1897) discussed a case where a heron choked on a frog, Cottam (1938) recorded a heron that died while trying to swallow a snake, and various additional cases have been reported where herons have died after trying to eat big fish like carp (e.g., Skead 1981). In January 1988, two dead Great blue herons A. herodias were discovered in the San Francisco Bay area of California, and in both instances the tail of a Pacific lamprey Entosphenus tridentata was projecting from the heron’s bill (Wolf & Jones 1989) [the two photos shown here, from Wolf & Jones (1989), both show the same heron]. The lampreys were 57.6 and 61.9 cm long respectively. Dissection revealed that, in both cases, the lampreys had been killed prior to swallowing (they had not, therefore, injured the herons during the attempting swallowings), and had gotten stuck in the oesophagus anterior to the proventriculus. The great girth of the lampreys meant that, in both cases, the heron’s glottis had been kept closed for too long, and death by suffocation was the result. Wolf & Jones (1989) further noted the possibility that the copious mucus secreted by the lampreys might have exacerbated the situation.

i-643e70d3fc3f0764d2354c05e5d40c4e-Wolf-&-Jones-1989_heron-vs-lamprey-1.jpg

Encounters between Great blue herons and large lampreys are presumably not that uncommon, as hinted at by the discovery – in relatively close proximity – of the two Californian individuals discussed here. Indeed, the various reports of choking in large herons ‘suggest that death caused by attempted ingestion of large or unwieldy prey by Great blue herons may be an important factor when considering adult mortality and population dynamics of this and similar species’ (Wolf & Jones 1989, p. 484).

For previous articles in the ‘over-enthusiastic swallowing’ series see…

Ref – -

Cottam, C. 1938. A fatal combat between heron and snake. Wilson Bulletin 50, 140.

Langdale, H. M. 1897. Heron choked by a frog. Zoologist 1, 572.

Skead, D. M. 1981. Goliath heron chokes on carp. Bokmakierie 33, 51.

Wolf, B. O. & Jones, S. L. 1989. Great blue heron deaths caused by predation on Pacific lamprey. The Condor 91, 482-484.

Comments

  1. #1 Ian
    December 6, 2009

    Darren, you’ve been rather morbid lately. Not everyone has a fascination with animal deaths by swallowing. Still, I myself have found these recent posts rather intriguing.

  2. #2 Cameron
    December 6, 2009

    The reference to copious mucous in lampreys is interesting, I can’t help but wonder if they have a less specialized version of the hagfish’s famous slime. Lampreys and apparently non-amniotes in general were recently discovered to have keratins related to those used to make slime in hagfish; the protein in hagfish may also be affiliated with eggs and developing zebrafish were found to be expressing the keratins. Lampreys have filaments associated with club cells which may be involved in mucous production, although the composition of the filaments is not known.

    Schaffeld, Michael and Schultess, Jan. 2006. Genes coding for intermediate filament proteins closely related to the hagfish “thread keratins (TK)” α and γ also exist in lamprey, teleosts and amphibians. Experimental Cell Research 312(9), 1447-1462.

  3. #3 Martijn
    December 6, 2009

    Considering the diet of the modern Dutch heron, especially the Amsterdam variety, I’m waiting for the first case of one who choked on a Big Mac or Whopper.

  4. #4 gray Stanback
    December 6, 2009

    I,m getting tired of the choking animals-bring on the toads!!

  5. #5 Jerzy
    December 6, 2009

    Amsterdaamse heron choking on hamburger? Impossible. Maybe a certain Green Heron flying around Amsterdam now.

    Dutch grey heron can eat two whole chicken legs in a row. One goes in immediately, with the second one it must sit a little, with end of the leg protruding from the mouth. Whole chicken bones are eaten without problem. And very eagerly.

  6. #6 Blackbird
    December 6, 2009

    Once I saw a cat stalking a Grey Heron in Barcelona Zoo – there is a wild heron colony inside the zoo-, overenthusiastic you would think. The cat approached, crouching, up to half a meter of the heron. The heron casually turned, pointed, and – ouch, I still cringe at the thought of it – stabbed the cat in between its eyes with closed beak at the speed of light. The cat run away, but I bet it changed its ideas about herons if it survived. Good ‘eyes bigger than stomach’ series!

  7. #7 Darren Naish
    December 6, 2009

    It’s difficult to work out from the comments whether people want more ‘death by choking’ stuff or not: I suspect that the vocal nay-sayers are in a minority. Speak now or hold your peace.

    As for over-eager domestic cats, I recall a photo where a Japanese pet cat was leaping, arms spread, after a flying sea eagle. The cat was lucky: the eagle went unaware of the failed attack.

  8. #8 Charles
    December 6, 2009

    I once watched a Purple Heron try to eat an eel in a rice paddy in Bali. The heron got it part way down and then the eel wrapped the part of its body that was outside around the heron’s neck and held on tight. The heron couldn’t finish eating the eel. It was forced to spit the whole thing out and try again. I think that he was successful on his second try, but I was really rooting for that eel.

  9. #9 Ian
    December 6, 2009

    always more “death by choking.” I’m afraid my obituary might show up on here though, “man chokes to death eating whole avocado.”

  10. #10 Ace of Svens
    December 6, 2009

    More choking, please. My cat tried to attack a white-tail buck once. I don’t know what he would have doen if he caught it.

  11. #11 Allen Hazen
    December 6, 2009

    Isn’t one of the medieval kings of England — maybe John? — supposed to have died from “a surfeit of lampreys”?

    Sorry, that wasn’t a very helpful comment. More seriously…

    I suspect I could have yawned through a one-off “X tries to eat Y, which is too big, and dies as a result,” but the whole series is having a cumulative effect on me: there is something interesting about predator-prey relations here that I would never have guessed a priori! How many of us would have thought that “death caused by attempted ingestion of large or unwieldy prey by [[assorted predacious tetrapods]] may be an important factor when considering adult mortality and population dynamics of [[these]] species”?

    Thanks, Darren!

  12. #12 Albertonykus
    December 7, 2009

    The choking to death pictures are fasciating – or perhaps I’m merely sadistic.

  13. #13 Dartian
    December 7, 2009

    Darren:

    herons [...] also eat [...] birds including [...] grebes

    Which, perhaps somewhat surprisingly, can also prove fatal to eat; see McCanch (2003).

    Marginally on-topic: I once saw a herring gull Larus argentatus catch a European river lamprey Lampetra fluviatilis from a shallow stream. The gull eventually managed to swallow the lamprey (and survive, I suppose) but it wasn’t without quite a struggle. The lamprey wrapped its body around the gull’s head almost like it intended to strangle it. But down it finally went.

    It’s difficult to work out from the comments whether people want more ‘death by choking’ stuff or not: I suspect that the vocal nay-sayers are in a minority. Speak now or hold your peace.

    MORE DEATH BY CHOKING!!! (Was that vocal enough?) I know there are more predator choking death reports out there in the literature, including at least one mass death event, and I, for one, am looking forward to reading your take on them.

    Reference:

    McCanch, N. 2003. Grey heron choking on little grebe. British Birds 96, 86.

  14. #14 Andreas Johansson
    December 7, 2009

    The English king who supposedly died from a surfeit of lampreys was Henry I.

    And yes, more death by overenthusiastic swallowing!

  15. #15 Neil
    December 7, 2009

    Here’s the bold cat pic:

    http://www.dailyhaha.com/_pics/cat_eagle.jpg

    I enjoy all hubris, zoological or otherwise.

  16. #16 Dartian
    December 7, 2009

    Darren:

    the eagle went unaware of the failed attack

    Oh, I’m not so sure about that. The eagle seems to be a subadult white-tailed eagle Haliaeetus albicilla. In spite of their size, they are not exactly the most formidable of raptors (a golden eagle would be an entirely different matter). On the other hand, cats that are defending their territories (or their kittens) have been known to attack surprisingly large adversaries. Thus, I think it just might be possible that that situation really is what it seems to be at first glance: the cat is chasing away (although not actually trying to catch) the fleeing eagle.

    (Of course, there is also the possibility that the eagle is really fleeing from the human who took the photograph.)

  17. #17 Darren Naish
    December 7, 2009

    Dartian – now that I see the image again, I will admit that you may well be right. I had remembered it as being slightly different (memories are carved in wax, not stone, after all).

  18. #18 Christophe Thill
    December 7, 2009

    Over-enthisiastic swallowing is becoming a trend, here at least. I sens a Rule 34 coming on…

  19. #19 Zach Hawkins
    December 7, 2009

    There are rules!?
    This topic rule over all other ‘topic-of-the-week’ threads you have done Darren, it’s both though provoking and laughable at the same time!

  20. #20 Gwen
    December 7, 2009

    I’m enjoying this series. Sad, but interesting.
    I have something bizarre of my own to report. This morning we found a semi-mummified tree frog (Hyla) in our new clothes dryer. No idea how it got in there. It wasn’t in there when they brought it in. This means one or maybe two loads of laundry have been tumbled dry with a hylid frog instead of a fabric softener sheet.

    I automatically thought of this blog.

  21. #21 Jerzy
    December 7, 2009

    Another topic “done to death” on birdforum is what can Herring Gull eat and survive. Soap with a label which stayed on until it produced a pellet etc.

  22. #22 William Miller
    December 8, 2009

    Another vote for more ‘X tries to swallow Y. Z bad thing happens. X dies.’ posts. I’ve learned a lot from them; I’d heard of largemouth bass with sunfish stuck in their throats (though IIRC the bass wasn’t dead), but I didn’t know the phenomenon was so widespread.

  23. #23 Anthony Maltese
    December 8, 2009

    Good lord, I hope that Rule 34 does not apply to this topic!

    With that said, I am enjoying the topic. More please, but not just choking. After watching my budgie hump a rock this weekend, I’m certain that there are other interesting ways critters remove themselves from the gene pool.

  24. #24 Rob Jase
    December 8, 2009

    “It’s difficult to work out from the comments whether people want more ‘death by choking’ stuff or not: I suspect that the vocal nay-sayers are in a minority. Speak now or hold your peace.”

    Well its not my favorite topic but as long as you don’t do one on David Caradine you won’t jump the shark.

    Would you like me to see if I can get you copies of my daughter’s road kill photo album?

  25. #25 Christopher Taylor
    December 8, 2009

    Well its not my favorite topic but as long as you don’t do one on David Caradine you won’t jump the shark.

    Or, alternatively, the old observation that if Karen Carpenter had eaten Mama Cass’s sandwich, both may have lived.

    For the record, I think Michael Hutchence holds more prominence in that regard than David Carradine.

  26. #26 Dartian
    December 9, 2009

    Choking celebrities, eh? Tennessee Williams choked to death when he accidentally swallowed a bottle cap.

    Oh, and the song ‘King of Pain’ by The Police has the line ‘There’s a skeleton choking on a crust of bread’. The wondrous things that Sting has seen…

  27. #27 Graham King
    December 9, 2009

    “It’s difficult to work out from the comments whether people want more ‘death by choking’ stuff or not: I suspect that the vocal nay-sayers are in a minority. Speak now or hold your peace.”

    Darren, it’s fine by me; looks as if you’re on a roll with this topic! (Which reminds me.. as a kid I once saw a gull with the bulge of what looked like a bread morning roll lodged sideways in its neck.. beak raised, fidgeting, making strenuous efforts to get it further down. Quite uncomfortable to see. How on earth had it got it in? I don’t think my parents and brother and I saw the outcome, as we were driving past.

    As you say, the topic is zoologically significant. Everything (else also) is interesting in its own way. Maybe alternating days with other topics would enable you to keep everyone happy?

    After all, there’s plenty still to cover.
    ‘A was swallowed by B and survived’ stories..
    And are there pairings of species which are potentially mutually predaceous and where the outcome of each match hangs in the balance, based on individual stamina, skill and determination? With enough contributions, how about assembling a league table? Or a poster photo composite.. A getting swallowed by B getting eaten by C..

    Cat and eagle? Ok, but how about this? Walking on a limestone pavement hilltop in north of England years ago, our family pet spaniel (like us all) was startled by two low-flying jet fighter aircraft that suddenly roared past overhead. Unlike the rest of us, she immediately took off in full-speed pursuit of them. Ok, not literally.
    Now, that’s what I call ambitious.. on a number of counts.

    However, once on exiting the back door she froze stock-still and would not go further on spotting the Goodyear airship in the sky.

    She was also utterly spooked once in a field (driven to flee) by mere cows seen through mist.

  28. #28 Graham King
    December 9, 2009

    I just found this and linked stories .

    Snake swallows pregnant ewe. Can’t move. Regurgitates it.
    Snake swallows alligator and bursts.
    Snake swallows electric blanket; operated on, survives.

    Mindblowingness!

  29. #29 David Marjanović
    December 9, 2009

    Snake swallows alligator and bursts.

    Because it encountered a speedboat. That’s Florida after all.

  30. #30 Cale
    December 9, 2009

    Slightly off-topic, but one of my favorite stories anyways. When I was a kid by the sea, I was fishing on the docks one day and I noticed a juvenile/subadult blue heron watching me very intently… so the next fish I caught I threw towards it. Sure enough, that heron grabbed it without a second thought, and then stepped closer. I repeated the action until the bird was right there, taking food almost from my hands. I’m sure it would have, but I was more comfortable letting it pick it up off the ground. It was wonderful, of course, to have a wild animal taking food from me, overcoming its natural instincts to forge a momentary ‘friendship’ with me, but I was a bit scared. I heard a spooked heron can kill a man if he jabs him in the eye or nose.

  31. #31 llewelly
    December 10, 2009

    This means one or maybe two loads of laundry have been tumbled dry with a hylid frog instead of a fabric softener sheet.

    And you didn’t even notice. Fabric softener sheets are a scam.

  32. #32 Raven
    December 12, 2009

    I’ve got some pics of a heron swallowing a chipmunk here, if anyone doesn’t believe they really eat anything they can catch. (I definitely didn’t.) http://www.flickr.com/photos/neuralwizardry/sets/72157622987381590/

  33. #33 (((Billy))) The Atheist
    December 13, 2009

    Regarding house cats, we once had an orange and white shorthair who was a one-feline ecological disaster area. Never actually ate anything he (well, ex-he) caught, but he deposited dead snakes (including an adult copperhead), mice, rats, muskrats, birds etc. on our doormat. Once, we came home to find a lare (3-inch by 2-inch) chunk of deer fur with a little skin attached.

    And I love the choking on your food series. Would make an excellent book (though, most likely, not a childrens book (though I think teenagers would love it)).

  34. #34 Jerzy
    December 13, 2009

    I heard acount that tame heron actually pecks at human eyes, thinking its a glistening fish.

  35. #35 Roger
    December 18, 2009

    On the Thames in London I’ve seen a heron trying to swallow from the head down an eel which had its body wrapped round the heron’s neck. In this case the heron gave up and the eel escaped.

  36. #36 Calli Arcale
    December 22, 2009

    Gwen:

    I have something bizarre of my own to report. This morning we found a semi-mummified tree frog (Hyla) in our new clothes dryer. No idea how it got in there.

    In the “weird things found by Shuttle Orbiter processing crews” list there is a mummified tree frog. (AFAIK, not the actual frog, just a description of it.) It was found during Endeavour’s last overhaul period, if memory serves. It might have stowed away in a wing before launch and actually flown into space, but they felt it was more likely it had boarded the Orbiter after it landed in Florida and then gotten freeze-dried while being ferried by 747 to Boeing’s facility in California for maintenance.

  37. #37 dmaas
    December 22, 2009

    http://www.telegraph.co.uk/earth/earthpicturegalleries/6840710/Animal-pictures-of-the-week-18-December-2009.html?image=22

    Perhaps another for the collection, though this one likely didn’t make it to a lethal stage.

  38. #38 David Marjanović
    December 22, 2009

    though this one likely didn’t make it to a lethal stage.

    LOL! This one belongs on Failblog! :-D

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