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Reptiles vs Rain: |
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manofkent Member Joined: 23 Oct 2009 No. of posts: 5  View other posts by manofkent |
Posted: 23 Oct 2009 Hands up who knows how do reptiles react to rain in active season Esp in cooler conditions (Autumn and Spring) when nights are cooler? Now we all know our reptile and amphibian ecology/behaviour...don't we? hmm?: Reptiles bask in certain temps They bask at certain times of day They bask at certain times of year They hibernate at certain times ect blaa blaa, everything seems to be as per the famous Herps Workers Manual...right? But I question why I have been sent on a watching brief at night, in 10 deg C, in mid October in a heavy storm. A waste of client's money,,,over doing the "precautionary approach" perchance? Lets just have an ecology/biology answer/debate. **** **** BSc MSc AIEEM Ecologist 5yr exp |
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David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts by David Bird |
Posted: 23 Oct 2009 Do I really understand you correctly, that you have gone out at night in October in adverse weather conditions to look for Reptiles. Perhaps you or whoever has sent you out has not explained correctly to the client what conditons are required for sensible survey which is a mistake. I do see various consultancies that seem to like to make huge amounts of money by carrying out surveys at the wrong time of the year or in the wrong conditons, these will produce results that are detrimental to the herpetofauna that we are supposed to be protecting. After over 40 years experience I do not think that the herpetological community know all the correct conditions for reptiles or amphibians to be visible or active, I am still learning and seeing animals when I do not expect them. On the BHS CAT (Smooth Snake) survey animals were seen out basking on heather clumps in gale force wind and rain as well as other adverse conditions so one can never be ceratin when some animals may be out and about. I believe that there is a diurnal and thermoregulatory cycle that reptiles have to adhere to, within certain limits, to act normally and survive but there is also a behaviour cycle that includes feeding at different times of the year, the teritorrial and reproductive cycle that is also present and differs from site to site and population to population, sometimes just a matter of a few hundred metres away that causes animals to be active or visible and can be independent of the thermoregulatory cycle. This may give rise to anomalies as to when one sees the greatest or smallest number of animals out on any particular site. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
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Iowarth Admin Group Joined: 12 Apr 2004 No. of posts: 222 View other posts by Iowarth |
Posted: 23 Oct 2009 I really think David has summarised this extremely well. It is really completely impractical to carry out any sort of reptile assessment at this time of year, let alone in those conditions; a factor which some consultancies seem to ignore - I have even known one which carried out a reptile survey in November and consequently stated confidently that no reptiles were present. Now, there's a surprise! As for the Herps Workers Manual it is good general guidance. The fact that one will occasionally find lizards or snakes "basking" in wind, rain etc doesn't alter the fact that this is exceptional behaviour! And I have been watching reptiles and amphibians in the wild for many years (far more even than David - which makes me feel very old!) and I also am still learning. In fact, the more I learn the more aware I become of how little I know! Chris Chris Davis, Site Administrator Co-ordinator, Sand Lizard Captive Breeding Programme |
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manofkent Member Joined: 23 Oct 2009 No. of posts: 5 View other posts by manofkent |
Posted: 24 Oct 2009 This was not a survey. This was a well meaning, precautionary watching brief/destructive search works in an area which wouldn't "normally/in text books or from experience" have SWs (basking, feeding, hibernating in any large numbers)...but we were there as there was the risk of 1 or 2 getting within the jaws of machinary... I was hypothesising in my head, on site, in the pouring rain and getting cold, that the conditions didn't look massively conducive to reptile presence. In an absolute sense I feel that rain in cooler conditions could create conditions less favourable to reptiles. It certainly in my view, wouldn't make for better or neutral conditions based on a baseline day x. So on those sites which are assessed by competent staff as "low potential" for presence, might it be possible to lower the risk of construction recklessly killing or injuring reptiles by mitigating by weather. I'm sure there are flaws to this idea, please feel free to comment politely. And please keep it anecdote free and assume the good in consultants for now. (we know some are bad, but not all!) **** **** BSc MSc AIEEM Ecologist 5yr exp |
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Paul Hudson Member Joined: 24 Sep 2004 No. of posts: 33 View other posts by Paul Hudson |
Posted: 25 Oct 2009 What do You mean mitigating by weather? have You really got 5 years worth of experiance in these matters? Paul Hudson Paul Hudson |
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manofkent Member Joined: 23 Oct 2009 No. of posts: 5 View other posts by manofkent |
Posted: 25 Oct 2009 I admited before I posted that comment that there may be some "flaws". And it seems you're right onto them. I apologise, it's a bit wacky. It's just interesting to explore ideas. And I'll put it to bed if it's too outrageous. Assuming everyone is happy to debate, I'll continue. How do people feel about the following hypothesis: "all things remaining the same, the chance of slow worms being present on grassland will be reduced during periods of heavy rain*." I've deliberately not defined any terms for the purpose of debate: PS I'm not endorsing this view, but waiting on the debate to take an informed view. I'm aware of the IEEM Code of Practice, and would not recklessly go ahead with something based on speculation. Its just good fun to have the debate with clever people like yourselves. Thank you so far for your comments so far, it's appreciated. **** **** BSc MSc AIEEM Ecologist 5yr exp |
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Iowarth Admin Group Joined: 12 Apr 2004 No. of posts: 222 View other posts by Iowarth |
Posted: 25 Oct 2009 Hi I don't believe your hypothesis can stand if we are to take it's wording literally. In general terms it might be reasonable to say ""all things remaining the same, the chance of reptiles being visible on grassland will be reduced during periods of heavy rain." I have changed both 'slowworms' and 'present' on the following bases:- i) the revised phraseology could be applied to all reptiles. and ii) since slowworms tend towards a fossorial life style and are seldom visible in the open, heavy rain will have virtually zero impact on their presence, although some impact on their visibility. In the remaining species exactly the same applies - except that their visibility will be more greatly reduced. Any more takers? Chris Chris Davis, Site Administrator Co-ordinator, Sand Lizard Captive Breeding Programme |
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manofkent Member Joined: 23 Oct 2009 No. of posts: 5 View other posts by manofkent |
Posted: 25 Oct 2009 That sounds reasonable. It's important that you've picked up on being species specific. That will be good for people viewing this in the future. It also makes sense that slow worms will be less visible during periods of rain, but do not necessarily depart the area, rather hide/return to ground. Without being arguementative, rather, continuing the debating process. May I have your opinions on the hypothesis when assuming that cracks/crevices/holes in the ground are sparse. I wonder whether slow worms might (on a survival basis) depart open grassland in favour of sheltered ground off site. Do we know enough about slow worm behaviour to say for certain. Thank you for your patience. **** **** BSc MSc AIEEM Ecologist 5yr exp |
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Iowarth Admin Group Joined: 12 Apr 2004 No. of posts: 222 View other posts by Iowarth |
Posted: 25 Oct 2009 Continuing the debating process, perhaps even the term "open grassland" covers too wide a habitat range. In the case of true rough grassland, even with a relatively low level of cracks/crevices/holes there is a plenitude of suitable refugia within grass tussocks - however open. My experience, including, various mitigation projects as well as study in the wild suggests that these, together with the more obvious candidates such as logs and stones are the more common refugia. Conversely, in an open area of relatively short, non-tussock forming grass, with an absence of other refugia I would expect few hiding places and as a consequence slowworms to be present in quantity only if conditions were appropriate for hunting and more suitable habitat was immediately adjacent. To that extent I believe your hypothesis might hold. I would dearly love someone else to argue with either both of us though! Chris Chris Davis, Site Administrator Co-ordinator, Sand Lizard Captive Breeding Programme |
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Jonathan Senior Member Joined: 08 Sep 2009 No. of posts: 68 View other posts by Jonathan |
Posted: 25 Oct 2009 [QUOTE=manofkent]all things remaining the same, the chance of slow worms The slow-worms are already present, what you need to define is their level of activity, very hard to do if they are making use of vole runs and subterranean access, which would in themselves be sheltered. Would their position before, during or after rainful change? Hunting ranges should increase post rainfall as their prey items are in the open and activity is heightened. "England Expects" |
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calumma Senior Member Joined: 27 Jun 2003 No. of posts: 351 View other posts by calumma |
Posted: 26 Oct 2009 As others have mentioned, detectability of a species is a critical issue that can be very difficult to control for. Slow-worm home ranges are relatively small (compared to snakes) and the animals are unlikely to move significant distances. If survey work has revealed the presence of slow-worms in an area of habitat, it is reasonable to assume that the animals will be present regardless of local weather conditions. That said, I have had sites where slow-worm encounter rates do display seasonal variation across different habitat areas. However, I cannot say whether that is due to fluctuations in occupancy or detectability (the latter caused by local variations in activity). Lee Brady Kent Herpetofauna Recorder | Independent Ecological Consultant |
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Robert V Senior Member Joined: 06 Aug 2004 No. of posts: 717 View other posts by Robert V |
Posted: 27 Oct 2009
Not sure about slow worms, but I can say that over the years of grass snake watching, without doubt the best conditions to see them is in light to medium drizzle on cloudy warm days with no wind. As soon as a breeze picks up to visibly move surrounding veggy, Grassys are off. But Adders don't mind the wind so much, as long as their sheltered spot by a log etc is not too exposed. But surveying at night? I question the point of that. R RobV |
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herpetologic2 Senior Member Joined: 15 Jun 2004 No. of posts: 1369  View other posts by herpetologic2 |
Posted: 28 Oct 2009 [QUOTE=manofkent] Hands up who knows how do reptiles react to rain in active season Esp in cooler conditions (Autumn and Spring) when nights are cooler? Now we all know our reptile and amphibian ecology/behaviour...don't we? hmm?: Reptiles bask in certain temps They bask at certain times of day They bask at certain times of year They hibernate at certain times ect blaa blaa, everything seems to be as per the famous Herps Workers Manual...right? But I question why I have been sent on a watching brief at night, in 10 deg C, in mid October in a heavy storm. A waste of client's money,,,over doing the "precautionary approach" perchance? Lets just have an ecology/biology answer/debate.[/QUOTE] Hmmm now why would you be working at night? I suspect that possibly this is a highways job? I have been sent out on 'watching brief' type work mainly on highway related jobs. This was mainly because of the remote possibility of amphibians or reptiles being present. On highways various areas are ideal habitats such as hedge banks, rough grassland and scrubby banks. The reason that this work was at night is due largely to the limitations scheme - i.e. this work often is done over night due to less traffic at that time. A road closure if required would not disrupt the main flow of traffic. I also tend to find that highway related work does not take into account the seasonality of reptiles. We all know that it is best to work on reptiles during their active period. Lots of work though starts in the late part of the year and in the case of highways or railway works they do not delay works until the year after and so the work is scheduled and the ecologists then supervise the works to rescue any animals found Of course the work is pointless in many cases and does nothing for reptile conservation. And of course you need the several hundred metres of reptile fencing for good measure - The money can be better spent on more worth while measures but it is often that the client does not want to deal with third parties and opts for the more expensive but less valuable (in conservation terms) course of action. Which means that young consultants are sent out in all weather to provide supervision. J Vice Chair of ARG UK - self employed consultant - visit ARG UK & Alresford Wildlife |
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manofkent Member Joined: 23 Oct 2009 No. of posts: 5 View other posts by manofkent |
Posted: 28 Oct 2009 I think the comment that "Slow-worm home ranges are relatively small (compared to snakes) and the animals are unlikely to move significant distances" ...is an important one to remember. Rain or unfavourable conditions would not therefore be any reason to let up on efforts to prevent killing/injury during works (all things remaining the same). I'm sure we all accept the note that such work like this can seem generally "pointless" in terms of conservation. But I'm sure a whole new thread could be set up on that. If you're a consultant, I guess it's up to us all which contracts we take, or don't. **** **** BSc MSc AIEEM Ecologist 5yr exp |
- Reptiles vs Rain |