Sunday, 11 October 2015

Parotoid (alternatively paratoid) Gland in American Toads

     The parotoid gland is found on the back, neck and shoulders of toads. It secretes a milky alkaloid substance called bufotoxin, to deter predators. Bufotoxin operates as a neurotoxin.
     In the picture of an American Toad Anaxyrus americanus americanus below, taken locally in Cambridge, ON, the raised glands are very visible, located somewhat behind the eyes.



     American Toads present an entire range of colouration, as can be see from the following pictures, all from an area within a thirty kilometre range from my house. Doubtless the colour of the skin can change hue depending on environmental conditions and the substrate in which the toad finds itself.








     In all instances the parotoid glands are clearly visible, although not as prominent as in the first picture, where they are a lighter shade than the rest of the toad's skin.
     I have no doubt that the secretion of bufotoxin is effective as an anti-predator strategy in many instances, but as far as I can tell, it appears to offer little defence against avian predators such as Broad-winged Hawk Buteo platypterus or Great Blue Heron Ardea herodias.

14 comments:

  1. A very informative blog, David, with clear photos.
    Gr Jan W

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  2. Interesting post! I don't think our local toads change colour, they're always greyish brown, but they also have the parotoid glands.

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  3. Hello David, interesting information about these Toads.
    Enjoy your week.
    Regards,
    Roos

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  4. The introduced Cane Toad has the same glands here - not good for native wildlife.

    Cheers - Stewart M - Melbourne

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  5. Que sapos más bonitos tenéis en Canada, son preciosos. Un abrazo desde España.

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  6. Superbe individu David !
    Belle rencontre

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  7. I guess I might be considered a two-legged predator to a toad. Must say I'm unlikely to feel the need to eat one now. Nevertheless thanks for your pictures and the information Mr G.

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  8. Dearest David,
    Guess toads get eaten a bit less than frogs, but still as you already mentioned, it is NO life insurance for them!
    Love your photos, vivid detail.
    Hugs,
    Mariette

    PS I have replied to your comment on my post: Hibiscus Blue Chiffon on Patio. We know quite well that hummingbirds live off nectar but they also do ingest some of the pollen.
    Both of us are micro biologists...

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  9. Don't really know much about toads, I guess there must be a few species here but I can't recall seeing any.

    Bound to be some desperate lowlifes who try licking those toads to see if they get high............or is that just an urban myth?

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    Replies
    1. Maybe when the princess kissed a frog it was really a toad and that is why she thought it turned into a prince!

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  10. Nice to see all different frogs.
    Beautifully photographed.
    Greetings Tinie

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  11. These toads are really special to see.
    The first is also separately with those glands on the back of its head.
    The other also have beautiful colors and drawings.
    Instructive indormatie and so I learn so again at some :-)

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