Striated Heron: Big fish or small fry?

“The Striated Heron (Butorides striatus) is not picky in its food. Big fish or small fry – both can become its meal. It does not mind the extreme sizes of its catch and will eat whatever is available.

“A sequence of pictures captured the process of a Striated Heron swallowing a big fish that has a wider body than the bird’s head (above, below). It is a real wonder that its throat can expand so much to consume the fish complete with spiny fins. It stretched and straightened its neck to stay upright to help ease the fish down its throat. Amazingly, it took less than 2 minutes to swallow the big fish (for comparison, I have seen the physically larger Grey Heron (Ardea cinerea) consuming a similar-sized fish in about 20 minutes).

“After the heavy dinner, the bird looked sluggish with a huge bulging belly. For a brief period, it felt so heavy that it changed to a sitting posture to rest (below left). It puffed up and shook itself to get rid of its lethargy. It then proceeded to drink a few times – perhaps aiding digestion (below right). There is no further observation as I had to leave for another appointment.

“On the left is another Striated Heron taking a small fry, which looked so tiny that you can barely see it in its bill. In the field, the bird was seen stalking and plunging its bill into the shallow water. It was only later, while checking full screen images, that I realised that there was a tiny fry in its bill. The bird must have excellent vision coupled with pin-point accuracy to be able to pick out this tiny fry from underwater!”

Kwong Wai Chong
Singapore
4th December 2009

Note: The fish is always swallowed head first, so that the spines do not damage the oesophagus that can easily be expanded to cater for its large size. From here the fish enters the upper part of the stomach, the proventriculus, which is also expandable. Here, secretions from gastric glands that include hydrochloric acid, break down the proteins in the fish as well as dissolve some of the bones. The lower part of the stomach is the muscular gizzard that grinds the fish up as well as compact the remaining bones into a pellet. If Wai Chong was to remain and kept the heron in his sight, he could have observed the bird casting a pellet after a short interval.

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6 Responses

  1. Nice pics! Unbelievable that this bird can swallow the huge fish. It looked so awkward with the bulge in its throat that it is remarkable that it didn’t choke.

    Wondering what is the biggest fish that this bird can handle and whether birds choke when swallowing?

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  2. Have not come across birds choking when swallowing large prey. However, there are records of kingfishers being killed when the spines of the fish they swallow damage their throat.

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  3. wongchawhung

    i got one striated heron (small) and feeds it with fish and very aggresive type too

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  4. Does anybody know references, publications, or reports about birds choking on fish or other prey? I am especially interested in the reference about the kingfisher mentioned above.Please email me.

    Sincerely,
    Dr Bruno Walther

    Visit our video and text website about the biodiversity crisis
    http://www.crisisoflife.net

    Assistant Professor
    Master Program in Global Health and Development
    College of Public Health and Nutrition, Taipei Medical University
    250 Wu-Hsing St., Taipei 110, Taiwan, R.O.C.

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  5. There are these records from other parts of the world:

    Roadrunner tries to eat horned lizard. Splits neck open. Dies.
    http://scienceblogs.com/tetrapodzoology/2009/11/29/roadrunner-vs-horned-lizard/

    Heron tries to swallow giant lamprey. Chokes. Dies. Second heron tries same trick. Also chokes. Also dies.
    http://scienceblogs.com/tetrapodzoology/2009/12/06/heron-vs-big-lamprey/

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