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Slowworms at Night: |
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Herpetologic Member Joined: 02 Sep 2003 No. of posts: 35  View other posts by Herpetologic |
Posted: 09 Oct 2003 Has anyone found Slowworms out at night? Adders and Grass snakes are known to be active at night int he summer, A slowworm was found after dark within my Parents garden munching on a snail (10.30pm). Obviously the sighting of such a secretive reptile would be hard but has anyone stumbled across them after Dark? regards |
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Tony Phelps Forum Specialist Joined: 09 Mar 2003 No. of posts: 575  View other posts by Tony Phelps |
Posted: 09 Oct 2003 I am interested in the statement that grass snakes are active at night, am i missing something, is this anecdotal or is there something written up about this? I think also that it is only during exceptional warm conditions (i.e. this year) that the adder would be active at night also. Tony |
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Caleb Forum Coordinator Joined: 17 Feb 2003 No. of posts: 448 View other posts by Caleb |
Posted: 10 Oct 2003 I've only once seen a grass snake out at night, despite torching for newts in quite a few sites that supported them. The one I saw was a medium sized adult, resting in shallow water in a reedbed. It was pretty inactive. This would have been the summer of 1989 (I think) which was a pretty hot one. |
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David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts by David Bird |
Posted: 10 Oct 2003 Very interesting. I came to the conclusion many years ago that Slow Worms are very Nocturnal or at least Crepuscular in their habits. This stems from the fact that one of the first fairly large rescues I did on an area of regenerating heather and a lot of good Molinia habitat with over 400 tins I found that days where the night had abeen clear and therefore relatively cool I found hardly any Slow Worms under my tins the next day whereas when the night had been cloudy and relatively warm I had a much better catch the next day. I also found that with some tanks of rescued animals in mosss and Bracken litter where most Slow worms would be hidden, if I came down in the middle of the night .and where I kept them was very dark and not influenced by the moon,I would hear a lot of noisy activity and once the light was put on in the room would see the surface covered with very active slow worms mating or fighting. I know this situation is very artificial and not scientific but the two points do seem to add up, to me at least. I saw a talk once where the speaker was trying to correlate the number of animals found under tins with various factors including the various weather factors but these had all been on the time of capture as far as I could remember. I do not think there was no positive correlation to any factor. I did ask afterwards if any previous night time temperatures or other conditions had been recorded and plotted but was informed that thay had not but there were many other parameters that could have been recorded as well but had not been. I usually try to put my self at the level of the animal involved if that is at all possible and work out why they would do or not do things breaking it down into simple reasons if possible, if I do this I always seem to come up with the importance of night time temperatures rather than conditions in the following day. This also ties in with if my tins have a good depth of vegetation under them therefore giving a temperature and humidity gradient the adverse effects of very hot sun on the surface tin is minimised. I also try to make certain that many of my tins are angled in different directions and not all slanting southwards and have varying amounts of shade so I can find animals to be present in most conditions during the day, however I still find cold nights give the worst results. This does seem to be true for Smooth snakes as well but to lesser extents with Grass Snakes and Adders. I always find Grass Snakes to be nomadic and unpredictable on heathland or adjacent grassland areas and only seem to find a majority of snakes use tins when coming up to shed and find them right below the tin surface when the tins are at their hottest when I cannot hold them for more than a second or two so have not worked this one out. David British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
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Herpetologic Member Joined: 02 Sep 2003 No. of posts: 35 View other posts by Herpetologic |
Posted: 10 Oct 2003
Last year I found a grass snake within a pond at around 10.30pm in late May. It was very active and was moving along the edge of the pond I was surveying for newts. A week or so later I found a different grass snake swimming in a newt pond in the same area. Both these occasions the water in the ponds were warmer than the air temperature (steam was rising from the pond's surface) and the snakes were hunting I suspect. The Local warden had seen grass snakes hunting smooth newts under water this year in the daytime in the same pond. My Father found the Slowworm this year in the flower beds when he wa sout counting smooth newts frogs and toads with a torch. It was a warm night in August I think. A few nights later the night temperature dropped and nothing was out. I also feel that it would beneficial for Adders to come out on very warm nights and I suspect this may be happening more often or has it just always happened?
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calumma Senior Member Joined: 27 Jun 2003 No. of posts: 351 View other posts by calumma |
Posted: 10 Oct 2003 Jon, I have never seen grass snakes active at night when conducting amphibian surveys. However, I concur with David's observations on the importance of night time temperatures, depth of vegetation under refugia and ensuring that refugia are placed in such a way that different aspects are sampled. In fact I have had data loggers under refugia on one of my study sites this year and I should be able to relate previous nights temperatures with daytime encounter rate. Unfortunately night time activity is difficult to directly investigate since nocturnal slow-worm don't really need to use refugia for basking  .
Lee Lee Brady Kent Herpetofauna Recorder | Independent Ecological Consultant |
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GemmaJF Admin Group Joined: 25 Jan 2003 No. of posts: 2090  View other posts by GemmaJF |
Posted: 19 Oct 2003 A couple of references to late night activity of grass snakes, On page 44 of EN's Scientific series No.27 Reptile survey methods- Bill Whitaker: I ask because I remember seeing grass snakes hunting for great crested newts at about 11 o'clock at night. Tom Langton: I have seen the same kind of thing at 2 o'clock in the morning. Gemma Fairchild, Independent Ecological Consultant |
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calumma Senior Member Joined: 27 Jun 2003 No. of posts: 351 View other posts by calumma |
Posted: 19 Oct 2003 If you take into account the number of night time survey sessions by experienced herpetologists, nocturnal encounter rates for grass snake would appear to be very low indeed. Perhaps such observations are restricted to specific locales, times of the year or weather conditions? I rarely visit ponds late at night once the gcn season is over (mid-May ish). Lee Lee Brady Kent Herpetofauna Recorder | Independent Ecological Consultant |
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GemmaJF Admin Group Joined: 25 Jan 2003 No. of posts: 2090 View other posts by GemmaJF |
Posted: 19 Oct 2003 I've a site in mind where I hope to carry out targetted night surveys for adder next year, being bracken it's often possible to hear what they are upto and this will aid locating them at night. Nearby is a pond where grass snakes hunt for palmate newts in a fairly restricted area, this could be watched at night. Hopefully I'll be able to get some data on the conditions when both species are active at night at this site, if they are at all. You would think if it was a regular occurence grass snakes would be fairly easy to spot in open water whilst torching for GCN. Though I've a suspicion night activity of adder and grass snake might occur when day temperatures are getting restrictively hot in July/August. Gemma Fairchild, Independent Ecological Consultant |
- Slowworms at Night |