The smell of fear: |
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Vicar Senior Member Joined: 02 Sep 2004 No. of posts: 1181 View other posts by Vicar |
Posted: 11 Oct 2004 Just saw an episode of O'Shea on TV where he mentioned venomous snakes tracking prey which had been envenomated. He said experiments had shown that the snake can track its venom scent, and hence differentiate crossed tracks and find the prey it bit. It seems that may only be half the story !...Interesting article attached: http://www.slic.wsu.edu/kkardong/htm/trailing.htm Steve Langham - Chairman Surrey Amphibian & Reptile Group (SARG). |
evilmike Senior Member Joined: 15 May 2004 No. of posts: 85 View other posts by evilmike |
Posted: 12 Oct 2004 thats what Adders do, let the prey wander off and die and then follows its victimby the scent saves the snake injurying itself trying subdue its prey they only bite for a spilt second, interesting stuff indeed i think if i remember correctly that the scent can attract competition for other Adders that then may result in a iam bigger than you standoff females usually win them being larger. Mike Lister BSc hons Ecology & Env management |
GemmaJF Admin Group Joined: 25 Jan 2003 No. of posts: 2090 View other posts by GemmaJF |
Posted: 12 Oct 2004 Kelleway, L.G. 1982. Competition for mates and food items in Vipera berus. British Journal of Herpetology 6:225-230 Covers the bit about competition for food items. I'm sure I've heard mention that adder can differentiate the scent of an envenomated prey item and one that is not and this is how rivals are attracted. Gemma Fairchild, Independent Ecological Consultant |
Vicar Senior Member Joined: 02 Sep 2004 No. of posts: 1181 View other posts by Vicar |
Posted: 12 Oct 2004 I think...the article above suggests that some snakes can differentiate the smell of a bitten prey, regardless of envenomation. Although it doesn't state any explicit conclusion, I assumed it was scenting some signature due to the stressed nature of the prey. Maybe some physiological reaction to increased adrenalin levels ?? Steve Langham - Chairman Surrey Amphibian & Reptile Group (SARG). |
GemmaJF Admin Group Joined: 25 Jan 2003 No. of posts: 2090 View other posts by GemmaJF |
Posted: 12 Oct 2004 Could be, if anyone has anything more up-to-date I would be interested to read it. A paper was recently published in the Journal of Chemical Ecology that suggests slow-worms use chemical cues in much more advanced ways than was previously thought. I've always thought reptiles are probably much more aware of chemical cues than we give them credit. Gemma Fairchild, Independent Ecological Consultant |
Robert V Senior Member Joined: 06 Aug 2004 No. of posts: 717 View other posts by Robert V |
Posted: 07 Nov 2004
So, if the theory proves to be accurate and snakes do have the ability to track by odours given off in chemical reactions, does it not then follow, that, the snakes can dintinguish individuals within their own species and identify them by scent if not sight??? R RobV |
Robert V Senior Member Joined: 06 Aug 2004 No. of posts: 717 View other posts by Robert V |
Posted: 07 Nov 2004
.....Further to this, I'm hoping that Gemma will be able to somehow place on here, a sequence of four photographs taken last year in early August (apologies for poor quality but at least you get the basic idea). The smaller snake that starts closer to the camera was a juvenile (definitely not sexually mature) and so the interaction between them must have been something other than just a 'mating instinct'. If this sequence shows a deliberate move to identify an individual by scent by both snakes (see how the adult has moved nearer the water in the last frame) I'll let you all decide......I know what I think. R RobV |
GemmaJF Admin Group Joined: 25 Jan 2003 No. of posts: 2090 View other posts by GemmaJF |
Posted: 07 Nov 2004 Rob, not received any piccies but I'll put them up when they are sent. Gonzalo,A.,Cabido, B., Martin, J., and Lopez,P.2004. Detection and discrimination of conspecific scents by the anguid slow-worm (Anguis fragilis).J.Chemcial.Ecol, Vol.30, 8:1565-1573 may be of interested, the authors concluded that slow-worms 'probably' distinguish the scents of other males from their own and determine factors such as size and fitness to avoid confrontation, though suggest further research is needed. I've observed adder that had lost spring confrontations re-investigate a mating pair, the second investigation always seemed shorter as if they knew the male and also knew he was not worth taking on. Gemma Fairchild, Independent Ecological Consultant |
Robert V Senior Member Joined: 06 Aug 2004 No. of posts: 717 View other posts by Robert V |
Posted: 08 Nov 2004
Thanks Gemma, I tried to send them last night but all of the attempts failed. i'll try one of them now, so please let me know if a). It comes through ok and b). They will be able to fit on the screen in a meaningful sequence. R RobV |
GemmaJF Admin Group Joined: 25 Jan 2003 No. of posts: 2090 View other posts by GemmaJF |
Posted: 08 Nov 2004
Gemma Fairchild, Independent Ecological Consultant |
GemmaJF Admin Group Joined: 25 Jan 2003 No. of posts: 2090 View other posts by GemmaJF |
Posted: 08 Nov 2004 Hi Rob, think that was the right order, if anyone is having trouble seeing the sequence let me know and I'll resize the first two pictures to match 3 and 4. Gemma Fairchild, Independent Ecological Consultant |
Robert V Senior Member Joined: 06 Aug 2004 No. of posts: 717 View other posts by Robert V |
Posted: 08 Nov 2004
Thanks Gemma, I think, with a slide of the cursor, you could get the general idea eh? R RobV |
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts by David Bird |
Posted: 13 Nov 2004 There are a set of researchers in the U.S.A. that have spent their whole research life on Chemical cues, odours and post envenomation together with feeding behaviour in captivity and y mazes. The paper to have a look at is Kardong,K.V & Smith,T.L. 2002 Proximate factors involved in Rattlesnake predatory behaviour: A review. in "Biology of the Vipers" (Schuett, Hoggren, Douglas,Greene, eds.), Eagle Mountain Publishing, 2002. I t gives a list of 85 references mostly on Rattlesnakes but a few by Naulleau in the 1960's on Vipera aspis. David British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
- The smell of fear |