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Juvenile adder diet: |
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Peter Senior Member Joined: 17 Jan 2008 No. of posts: 260  View other posts by Peter |
Posted: 01 Aug 2008 I just wondered whether any research has been done regarding juvenile adder diet? I imagine that it would be quite some task to consistantly find mammalian and reptillian prey of a suitable size. Is there any evidence to support the theory of predation of invertebrates? 
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axel Member Joined: 16 May 2006 No. of posts: 31  View other posts by axel |
Posted: 01 Aug 2008 Last year a paper was published which conducted feeding trials with captive neonate V. berus, and found no instances of feeding on insects. In contrast the related Vipera renardi consumed inverts 98% of the time. The authors concluded that V. berus is a purely vertebrate feeder. Additionally, the venom of V. berus was found to not very toxic to crickets, in contrast to the frequent insect feeding species (such as V. renardi) have a venom which is highly toxic to crickets. The reference is Starkov et al. (2007) Toxicity of venoms from vipers of Pelias group to crickets (Gryllus assimilis) and its relation to snake entomophagy. Toxicon 49: 995-1001. You can get the abstract on google scholar, or if anyone wants the full PDF pm me your email and I can send it as an attachment cheers. |
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Vicar Senior Member Joined: 02 Sep 2004 No. of posts: 1181 View other posts by Vicar |
Posted: 02 Aug 2008 Hi Peter, I don't know of any references, but I've often been told that young Vb are very fond of juvenile Common lizards. You certainly do find an increased presence of juv Vb at Zv sites, so observation supports this info, but I've never seen one eating. Steve Langham - Chairman 
Surrey Amphibian & Reptile Group (SARG). |
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Peter Senior Member Joined: 17 Jan 2008 No. of posts: 260 View other posts by Peter |
Posted: 02 Aug 2008 Hi Steve,
There certainly is a plentiful supply of juvenile commons at some of the sites that I visit, but not all.
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Vicar Senior Member Joined: 02 Sep 2004 No. of posts: 1181 View other posts by Vicar |
Posted: 02 Aug 2008 Appleby, 'British Snakes'.  Steve Langham - Chairman
Surrey Amphibian & Reptile Group (SARG). |
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armata Forum Specialist Joined: 05 Apr 2006 No. of posts: 928 View other posts by armata |
Posted: 05 Aug 2008 Juvenile adders exist mainly on common lizards. Common lizards give birth some time before adders and at the time of adder birth the lizards are almost double their size; ideal prey for the juv adders. Interestingly, at Cors Caron, the juv adders prey on common lizards and the adults mainly on frogs. Some juv adders I have recorded taking adult common lizards, they look like a pork sausage can't even bend their body. 'I get my kicks on Route 62' |
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calumma Senior Member Joined: 27 Jun 2003 No. of posts: 351 View other posts by calumma |
Posted: 11 Sep 2008 I am also quite interested in this subject and have recently interrogated the KRAG database to identify possible trends. 125 sites have records of adder. Of those, 41 sites have records of adder, slow-worm and viviparous lizard (and sometimes grass snake). 12 sites have records of adder and slow-worm but no lizard. 8 of the 12 sites only have ad hoc records (i.e. no detailed survey work has been undertaken) so the absence of lizards is by no means certain. A further 2 sites have been thoroughly surveyed and lizards not recorded - but adder could not be confirmed either. The original adder records at these two sites are either incorrect or perhaps represent vagrants, but probably do not represent a population. That leaves 2 sites where reasonably detailed survey work has been undertaken. At these last 2 sites, only adult adder have been recorded. Interestingly at one site, adult male and female adder were observed close to a suspected hibernacula. I'm keen on collecting more data to try to determine what the fate of these two populations will be. I also examined the adder data and found 13 sites with both adder and viviparous lizard, but no slow-worm. Of these, 12 sites represented ad hoc records where no detailed survey work had been undertaken. However, one site had been thoroughly surveyed and slow-worm not recorded. This site was found to support both adult and juvenile adder. Not conclusive data by any means, but hopefully of interest. Does anybody else have data on species assemblages and lifestage structure for other areas? Lee Lee Brady Kent Herpetofauna Recorder | Independent Ecological Consultant |
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Vicar Senior Member Joined: 02 Sep 2004 No. of posts: 1181 View other posts by Vicar |
Posted: 12 Sep 2008 Here's a partial cut of the data from some of our 2008 monitoring sites (still on-going). Non-presence does not necessarily imply absence, just that no sighting has been reported.
Steve Langham - Chairman
Surrey Amphibian & Reptile Group (SARG). |
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calumma Senior Member Joined: 27 Jun 2003 No. of posts: 351 View other posts by calumma |
Posted: 12 Sep 2008 Steve So it looks like you also have at least one site (GNH) with adder and slow-worm that may lack lizard. Interestingly, your data also suggests that only adult adder have been recorded at this site. Is there any historical information to suggest that lizards used to occur? Is the site an area where adult adder hunt, perhaps situated close to other areas that may also support breeding adder and lizard? I can quite imagine the scenario where low numbers of adult adder are recorded at sites where lizards are absent (or present in such low numbers they are very difficult to record). The areas where females give birth are often close to hibernacula and it is perhaps these sites where the absence of lizards may become a critical factor. What I find interesting about the Kent records is that at one of the sites where lizards have not been recently observed, adult adder have been recorded close to hibernacula. Of course there is an issue with reptile recording about what actually constitutes a site. In attempting to identify key sites, KRAG are focussing on those areas where breeding and/or hibernating has been recorded. Different sites (or areas within a site) may offer different opportunities for different species. With adder, piecing this jigsaw together is obviously very important. There just aren't enough hours in the day! Lee Lee Brady Kent Herpetofauna Recorder | Independent Ecological Consultant |
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Vicar Senior Member Joined: 02 Sep 2004 No. of posts: 1181 View other posts by Vicar |
Posted: 12 Sep 2008 Hi Lee, The GNH site is fairly isolated and not large. I doubt that there is very much opportunity for migration from the site, and fully expect to identify hibernacula in time. It is a new core site, and only added to the long-term monitoring sites from June this year. I would expect to find juvenile adders there (eventually), as we know adult adders are seen more frequently than juveniles. I would not be surprised to find Common lizards at the site, Sand lizards are present; whose juveniles are likely to be predated. ---------- Just checked historical records, and Zv has been found on (GNH) site from 1990-2005. (The table was 2008 survey data only). There are also legacy records for immature Vb as recently as 2002. Steve Langham - Chairman
Surrey Amphibian & Reptile Group (SARG). |
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calumma Senior Member Joined: 27 Jun 2003 No. of posts: 351 View other posts by calumma |
Posted: 12 Sep 2008 Bill W has now emailed to let me know that the two Kent sites with adder but no lizards did in fact used to support lizards during the 80's and 90's (I've asked for the records!). Survey work is continuing at the two sites and it will be interesting to see whether lizards do in fact turn up (along with juvenile Vb) - I don't yet have the 2008 data. If lizards still remain elusive, we will have to broaden our survey area and identify other nearby lizard sites that may offer better potential for breeding adder. Lee Brady Kent Herpetofauna Recorder | Independent Ecological Consultant |
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will Senior Member Joined: 27 Feb 2007 No. of posts: 330 View other posts by will |
Posted: 13 Sep 2008 There's an interesting parallel with the London population of Aesculapian snakes; in their natural habitat on the Continent the neonates usually feed on lizards; there are none on Regents Canal and so presumably the population is limited by hatchlings having to find and swallow down nestling mammals. However I guess this is easier in Aesculapians as the hatchlings are that much larger than baby adders. Personally I don't know of any adder sites which have young and juvenile adders that don't have common lizards. Shame, really, that they won't touch Orthoptera unlike some vipers, given their abundance at this time of year. |
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Vicar Senior Member Joined: 02 Sep 2004 No. of posts: 1181 View other posts by Vicar |
Posted: 13 Sep 2008 Hi Will, Would they not also take frogs? we found frogs and juvenile El in the wooded area along the canal when last up there...but I don't know Aesculapians well enough to comment. Steve Langham - Chairman
Surrey Amphibian & Reptile Group (SARG). |
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will Senior Member Joined: 27 Feb 2007 No. of posts: 330 View other posts by will |
Posted: 13 Sep 2008 Hi Steve Good question; I guess they might - I hadn't thought of that in the case of London Aesculapians; I think it's quite rare for habitual amphibian feeding snakes to swap to mammals and birds later in life though. I did find a small London Aesculapian in the act of producing a dropping - and interestingly it had mouse hairs in it, but of course that doesn't mean the hatchlings don't take froglets, for example. |
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armata Forum Specialist Joined: 05 Apr 2006 No. of posts: 928 View other posts by armata |
Posted: 14 Sep 2008 Neonate adders will take small frogs and of course appropriate sized slow worms. I am sure that neo slow worms form a large part of the diet for neo smooth snakes. 'I get my kicks on Route 62' |
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calumma Senior Member Joined: 27 Jun 2003 No. of posts: 351 View other posts by calumma |
Posted: 15 Sep 2008 Tony, yes I have considered the role of slow-worms. What I don't know is, will the presence of slow-worms be enough to offset the lack of lizards? Lee Brady Kent Herpetofauna Recorder | Independent Ecological Consultant |
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AGILIS Senior Member Joined: 27 Feb 2007 No. of posts: 694  View other posts by AGILIS |
Posted: 15 Sep 2008 Interesting subject as to reptile diet I wonder how many barren sites are just the out come of animals starving to exstinction keith
LOCAL ICYNICAL CELTIC ECO WARRIOR AND FAILED DRUID |
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armata Forum Specialist Joined: 05 Apr 2006 No. of posts: 928 View other posts by armata |
Posted: 15 Sep 2008 Adders taking invertebrate prey I think has always been an assumption - old literature (Bell etc) tells of feeding on worms. Also we know other Vipera take inverts i.e. ursinii, even as adults. Other vipers, Echis, take centipededs and scorpions, copperheads (Agistrodon) have been recorded as adults feeding on cicadas. Slow worms have large litters, and although subject to predation from other sources probably enough to serve an adder population. I cannot think of an adder site that would lack both slow worm and common lizard. Like I said neo common lizards born earlier are optimum prey for neo adders born later. Also, how many neo adders feed before hibernation, a small percentage maybe, as in the spring virtually all the neos of previous year have a nice bulge, and I think that this period represents the bulk of initial feeding regime. 'I get my kicks on Route 62' |
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Masked Marvel Member Joined: 15 Sep 2008 No. of posts: 6 View other posts by Masked Marvel |
Posted: 15 Sep 2008 Very small adders do indeed eat full grown viviparous lizards. The adder in the picture regurgitated the lizard after I captured it during a relocation. I didn't measure them both exactly, but the lizard might just win by a nose. Felt quite bad about it as that lizard must have taken some swallowing...  |
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armata Forum Specialist Joined: 05 Apr 2006 No. of posts: 928 View other posts by armata |
Posted: 15 Sep 2008 Yes that always amazes me, like I said before little adder can't bend, looks like pork sausage!! 'I get my kicks on Route 62' |
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- Juvenile adder diet |