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Do Toads/Frogs see young as "Lunch"?..: |
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TVFrog Member Joined: 18 Feb 2004 No. of posts: 31  View other posts by TVFrog |
Posted: 18 Jul 2005 Hi All, Came back from a weekend away last night to find an adult Toad sitting in my pond, partially submerged under duckweed - probably cooling down with all the hot weather we've been having. Anyway - also have loads of Froglets in/around the pond at the moment - doing rather well - was wondering if adult Rana/Bufo would ever see the youngsters as potential prey? Has this ever been observed in the UK species? Cheers, Mark. |
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Caleb Forum Coordinator Joined: 17 Feb 2003 No. of posts: 448 View other posts by Caleb |
Posted: 18 Jul 2005 I have seen an adult toad take a young toad. I've never seen one eat a young frog, but I'm sure they would if the opportunity presented itself. |
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TVFrog Member Joined: 18 Feb 2004 No. of posts: 31 View other posts by TVFrog |
Posted: 18 Jul 2005 Ooops! Then theres not much I can do. Hopefully there are plenty of insects that she'll take a fancy to instead.... |
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TVFrog Member Joined: 18 Feb 2004 No. of posts: 31 View other posts by TVFrog |
Posted: 18 Jul 2005 Has anyone else observed cannibalism amongst Rana/Bufo? |
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GemmaJF Admin Group Joined: 25 Jan 2003 No. of posts: 2090  View other posts by GemmaJF |
Posted: 18 Jul 2005 I've not witnessed intraspecific predation (great term for eating each other eh??) in Rana temporaria directly, but I have seen anecdotal evidence of it. I moved approximately 250 common frogs from an enclosed courtyard in London a few years ago. I was told that large amounts of spawn had been laid both that spring and also the following year and many tadpoles had hatched and grown to a good size. However there were no small frogs, not one. The smallest were approximately 2.5 inches snout to vent. So, I would guess that the entire two previous years cohorts were missing entirely. Add to this that I saw no evidence of terrestrial inverts in the courtyard during extensive destructive searching, and I concluded the only food source for any of the frogs was smaller frogs. Interestingly the largest specimens were all malnourished. So I guess there is an optimum size for preying on your own species when youÆre a common frog A caveat to this is that there may have been other explanations for why the previous two years offspring perished, but it wouldn't explain what the medium sized frogs had been thriving on. In all I would say adults common frogs will not differentiate their young from any other moving mouth sized morsel, but if plenty of other food is available it will not happen that often, else I doubt they would still be here. I know many species rely on various dispersal tactics to avoid intraspecific predation of their own young. Marsh frogs certainly eat other smaller frogs also. Gemma Fairchild, Independent Ecological Consultant |
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TVFrog Member Joined: 18 Feb 2004 No. of posts: 31 View other posts by TVFrog |
Posted: 19 Jul 2005 Hi Gemma, Thanks for your detailed response, an interesting story. On the face of it I'm inclined to agree. Even under "normal" circumstances in ones back garden, despite predation by birds, predation at taddy stage, not surviving hibernation etc. one would still expect even a few Froglets / Toadlets to survive to 2/3 years old, or just past the first year - so in your experience the complete absence of *any* yearlings would seem strange. Bearing in mind the other locational issues one could conclude intraspecifc predation had been occuring. Interestingly the high concentration you quote (250 examples) would also indicate the young adults/mature adults weren't being predated "naturally" themselves, meaning a further shortage of invert-type food leading to possibly even more intraspecifc predation!!? I wonder if the same would occur if we were talking Toad here instead of Frog....? Also - theres some info on the web re' "gape size" in Frogs - I assume this discusses what the Frogs could feasibly attempt to catch 
BTW - Does Marsh Frog = what we used to call years ago the "European Edible Frog"? As before - hopefully I've got enough alternative food sources in my garden to ensure any adults are "catered" for ;-) enabling at least a few Froglets to survive. Cheers, Mark. |
- Do Toads/Frogs see young as "Lunch"?.. |
