Hatched Already?: |
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Paul Ford Senior Member Joined: 06 Sep 2006 No. of posts: 124 View other posts by Paul Ford |
Posted: 19 Jun 2010 I found this one in Dorset on Thursday: It was tiny - surely one of this years? Paul
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Robert V Senior Member Joined: 06 Aug 2004 No. of posts: 717 View other posts by Robert V |
Posted: 20 Jun 2010 Paul, it must be this years as its so tiny. But it must have been an autumn mating and eggs partially incubated over the winter, otherwise 67 + 65 would have it a January mating - not with the jan we had this year. RobV |
will Senior Member Joined: 27 Feb 2007 No. of posts: 330 View other posts by will |
Posted: 20 Jun 2010 Hi Rob I'm assuming you mean fertilized eggs stored in the oviducts of the hibernating female, then laid in spring, rather than eggs laid in autumn and still viable the following spring? if so, is this phenomenon related to global warming, specifically warmer / longer autumns ? |
Robert V Senior Member Joined: 06 Aug 2004 No. of posts: 717 View other posts by Robert V |
Posted: 20 Jun 2010 Hi Will, yes thats exactly what I mean. But I don't think its down to global warming, more sort of nature's insurance policy with the females taking any opportunity to mate that presents itself, just in case the males in local groups do not make it through the winter. There certainly seems to have been many more sightings of autumn matings in the last few years but this may be down to people become more aware of nature generally. Also, by early hatching the neos get a head start in response to dwindling numbers of prey items. If, in the usual course of events the neos hatch in august, september most of the baby frogs, toads etc have dispersed, whereas if a hatching of neos takes place in May, they can still catch the pre terrestial amphibs at the ponds. Just theories R RobV |
will Senior Member Joined: 27 Feb 2007 No. of posts: 330 View other posts by will |
Posted: 20 Jun 2010 Interesting stuff Rob; I've seen autumn mating myself a couple of years ago, which took me by surprise. I'm impressed with the flexibility/plasticity of mating when it comes to grass snakes, compared say with adders - eg breeding in autumn, feeding in advance of, or during the spring breeding period, and also seeming to be able to breed as soon as they emerge from hibernation rather than requiring a lying out period to mature sperm etc. |
stuart Member Joined: 26 May 2005 No. of posts: 12 View other posts by stuart |
Posted: 20 Jun 2010 Despite its small size I believe it is one of last years young. I have found them like this in and around the previous years breeding heaps many times in the past. On a site I survey I noticed the gravid females to be about 2-4 weeks behind on an average years breeding (spring was late and cold in the midlands) and I dont believe the breeding cycle could be so advanced for the time of year even in the south of the country Regards Stuart |
Mark_b Senior Member Joined: 26 Jun 2008 No. of posts: 79 View other posts by Mark_b |
Posted: 21 Jun 2010 I came across this youngster on the 10th May. 3 grams. 21.5cm total length I have caught about 3-4 others this size, including one yesterday also weighing 3 grams These ones have got to be last years? In last years grass snake young thread .... [QUOTE=JohnBaker] Hi Chris, I've found very small grass snakes at unexpected times of the year. e.g. one weighing 4 g in May 07 and another weighing 3 g in May 08. This is pretty much the weight of hatchlings. This year I found another ten tiny grass snakes in June. I didn't weigh these, but they looked hatchling size. I assume that these are simply babies that have got off to a bad start in life and did not manage to grow at all between hatching and the following spring. Given the cool summers of 2007 and 2008 it doesn't seem unreasonable to think that hatchlings might be appearing late in the year and going into hibernation without feeding and some of them still not managing to put on weight the following spring. John Baker [/QUOTE]
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Robert V Senior Member Joined: 06 Aug 2004 No. of posts: 717 View other posts by Robert V |
Posted: 21 Jun 2010 Stuart / John /Mark, just because you are used to dealing with a certain set of circumstances and usually find the average in your studies, you simply cannot discount the fact that autumn matings may lead to stored eggs within the female over winter and an early start in spring, no one has yet proven it either way. And Mark, the measurement you gave is the key to your find, ie 21.5cms or 215mm, when the hatchlings are around 150-160mm, so they have in fact grown irrespective of the weight. Cheers Rob RobV |
Paul Ford Senior Member Joined: 06 Sep 2006 No. of posts: 124 View other posts by Paul Ford |
Posted: 22 Jun 2010 The neo in my picture was approx 15 cm. I caught a bit of Springwatch a couple of weeks ago and Chris Packham produced a "hatched" grass snake egg from his mate's compost heap.... Paul |
will Senior Member Joined: 27 Feb 2007 No. of posts: 330 View other posts by will |
Posted: 22 Jun 2010 Hi Paul I think I saw that bit too, but if it was the same clip I'm not sure he was suggesting it had hatched this season, just that it was an empty shell from some time in the past. It sounds like we have several hypotheses as to the existence of tiny grass snakes at this time of year, all of which are possible and not mutually exclusive. I am intrigued by the purpose of autumn matings, if grass snakes are unable either to store sperm or fertilized eggs over the winter (maybe they just enjoy it!) - perhaps someone has done research on the continent into this? If not, it would make a good research project Will |
JohnBaker Member Joined: 21 Nov 2003 No. of posts: 5 View other posts by JohnBaker |
Posted: 22 Jun 2010 Blimey. Herps on Springwatch. That is an unusual. I missed it. I am not going to make any guess as to when these small grass snakes hatched. Just an observation and a question. Observation: grass snake egg shells can be very persistent. I can find egg shells at this tmie of year from clutches that hatched last year (I am sure a biochemist could extract some useful anti-fungal agent from snake eggs). Quesion: What was the weather like this year at the time eggs would have been deposited in order to yield hatchlings now? John Baker John Baker |
Paul Ford Senior Member Joined: 06 Sep 2006 No. of posts: 124 View other posts by Paul Ford |
Posted: 22 Jun 2010 [QUOTE=will] Hi Paul I think I saw that bit too, but if it was the same clip I'm not sure he was suggesting it had hatched this season, just that it was an empty shell from some time in the past. [/QUOTE] I must admit I dismissed it at the time thinking that is was much too early - but then I found that tiny neo??? I was in Dorset the week commencing the 10th of April and although there were frosty nights the weather was VERY warm.....? Paul
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arvensis Senior Member Joined: 15 Mar 2006 No. of posts: 445 View other posts by arvensis |
Posted: 22 Jun 2010 Paul, Is that the site in Dorset we looked at last year? Mark Hampshire Amphibian and Reptile Group. |
Paul Ford Senior Member Joined: 06 Sep 2006 No. of posts: 124 View other posts by Paul Ford |
Posted: 23 Jun 2010 Hi Mark, Yep - thats the one Paul |
herpetologic2 Senior Member Joined: 15 Jun 2004 No. of posts: 1369 View other posts by herpetologic2 |
Posted: 23 Jun 2010 [QUOTE=will] Hi RobI'm assuming you mean fertilized eggs stored in the oviducts of the hibernating female, then laid in spring, rather than eggs laid in autumn and still viable the following spring?? if so, is this phenomenon related to global warming, specifically warmer / longer autumns ? [/QUOTE] if this is the case then yes this would be related to climate change - which is occurring at a faster and faster rate Vice Chair of ARG UK - self employed consultant - visit ARG UK & Alresford Wildlife |
herpetologic2 Senior Member Joined: 15 Jun 2004 No. of posts: 1369 View other posts by herpetologic2 |
Posted: 23 Jun 2010 [QUOTE=Paul Ford] I found this one in Dorset on
ipleyDorset18062010031.jpg"> It was tiny - surely one of this years? Paul ? [/QUOTE]Very hard to determine, my money would be on last year's as it may not have had much food yet this year in order for it to grow. Or it was a very small snake when it hatched last year. The weather was quite bad last year so a delayed hatching in October is possible J Vice Chair of ARG UK - self employed consultant - visit ARG UK & Alresford Wildlife |
Robert V Senior Member Joined: 06 Aug 2004 No. of posts: 717 View other posts by Robert V |
Posted: 23 Jun 2010 Jon, you don't know that its' down to global warming - prove it please. And while you're at it, prove that it's not a natural selective process mechanism within Grass Snakes adapting to the shortages of both males snakes and / or prey items. Cripes, is there anything worse than people that discount others theories / suggestions because they can't see past their own?? R RobV |
herpetologic2 Senior Member Joined: 15 Jun 2004 No. of posts: 1369 View other posts by herpetologic2 |
Posted: 23 Jun 2010 Hi Rob How does the lack of food or males snakes influence the mating process? particularly the storage of fertilised eggs over the winter period If the weather enables activity until very late in the year - say mating occurs in October - which I have experienced in Southern England and I think more people are seeing this - though I think it is more common in warmer climates such as southern Europe what does that tell you? Jon Vice Chair of ARG UK - self employed consultant - visit ARG UK & Alresford Wildlife |
herpetologic2 Senior Member Joined: 15 Jun 2004 No. of posts: 1369 View other posts by herpetologic2 |
Posted: 23 Jun 2010 PS is there any evidence that 1. grass snake eggs survive winters in the egg laying area or 2. has any female grass snake been found still gravid with eggs in a hibernation site and then lay them the next spring? J Vice Chair of ARG UK - self employed consultant - visit ARG UK & Alresford Wildlife |
arvensis Senior Member Joined: 15 Mar 2006 No. of posts: 445 View other posts by arvensis |
Posted: 24 Jun 2010 [QUOTE=Paul Ford] Hi Mark, Yep - thats the one Paul [/QUOTE]Ah, good to see they're still there - there's also GCN's there as well.... Mark Hampshire Amphibian and Reptile Group. |
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