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Post by Killian on Sept 27, 2005 11:11:46 GMT
I hear there are loads of these guys living feral in southern England, because they are relatively recently introduced to the UK in large numbers very few of these specimens are sexually mature as yet.
In the future this species has the potential to become a UK breeding species. Do you think their eggs would be able to hatch naturally in this climate? they are found very far north into Canada, so in theory it is possible.
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Post by adamanuran on Sept 27, 2005 14:13:29 GMT
I don't think it is very likely at present. With global warming it is possible but this would be in a lot of years to come. Emys orbicularis are found on more northern latitudes than most places in Britain (except Scotland) Yet for some reason there are very few documented cases of sucessful outdoor incubation. It is possible that some parts of the west coast could be suitable for these species due to the influence of the warming gulf stream. Whatever the theory though, we should really go out on the hunt for these things as the amount of ecological damage that such alien beasties could do to our native fauna would be collosal. Look at the american bullfrog! There is always also the risk of introducing disease with animals from such disparate locations that native animals would be unlikely to have any resistance to. I hate aliens!!!!!!!! The snapper i have is a "feral" animal and most certainly of breeding age. The only good thought about their release is the fact that not as many of them have been released as the red eared terrapin and the likelihood of two oppositely sexed specimens occurring in the same pond is quite slim!
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Post by willj on Sept 27, 2005 14:58:24 GMT
not all aliens do harm though, but most do. hyla arborea and mesotriton alpestris exisist in perfect harmony with other species
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Post by Killian on Sept 27, 2005 15:25:31 GMT
Snappers are a definite menace they have been known to drag birds as large as mallards under water not to mention the potential to remove a finger of a curious child.
I dont think any alien is acceptable as if they were meant to be here they would be here!! although they are facinating.
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BenJT
New Member
Posts: 29
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Post by BenJT on Sept 27, 2005 16:43:01 GMT
I've read that in mesotriton alpestris colonies in Newdigate (surrey), have depleted small ponds of their frog populations by eating all the spawn and tadpoles, (source "Amphibians and Reptiles of Surrey").
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Post by willj on Sept 27, 2005 17:42:24 GMT
i wouldn't say that they would do that any more than other "triturus" would. but you could be right.
Killian: i'm not trying to say that aliens are good, the truth of the matter is that they shouldn't be here. though it does seem a mistery to my why species like salamandra salamandra and mesotriton alpestris didn't find there way here when the land bridge was formed. but it is very easy to label all introduced species as bad. that's why they are generally split into to groups, Aliens that do damage like triturus carnifex and rana castebaenia. and naturalised species like mesotriton alpestris and hyla arborea.
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Post by adamanuran on Sept 27, 2005 19:40:35 GMT
I personally like the idea of some species being introduced into the uk. Some of the official introductions are a little far fetched such as the reintroduction of the euro pond turtle into east anglia. I don't think anyone can believe that the natural ecosystem hasn't changed since they became extinct in Britain. The so called "mis-guided" attempts to increase british biodiversity can be seen as an unnatural thing. I think the release of wall lizards, midwife toads, alpine newts, green frogs and gtfs all which have proven to coexist without problems (as they all ways have done on the continent) is actually not such an unnatural thing. Lacertid lizards are renowned to be very territorial to others of the same species never mind others. I have a photograph of muralis and agilis basking together with no problems at all! I apologise to everyone for my long winded answer but i would quite like to raise the argument "what is natural, what is native?" Once a native species was regarded as one which had found its own way to a location and sucessfully bred there. This was true of the Galapagos so why shouldn't it be true here? With 22 miles separating us from the mainland, is it not possible that such species as Alytes obstetricans could not raft across, they are most certainly able to survive brackish conditions so a short journey on a vegetation raft covered by a leaf may be possible. Also we as human beings like to remove ourselves from nature, the fact that we are a living species with genetic relationships to bacteria etc like every other species seems to slip out of most peoples minds. We are probably the largest influencial force acting upon the planet. Most of it may be having a bad effect, but we are still natural. Ducks carry daphnia from pond to pond, is that any different to us moving newts? European species are less likely to disrupt our ecology unlike the perfectly accepted and legal release of Pheasants each year.
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Post by Killian on Sept 28, 2005 1:01:59 GMT
don't forget humans are not native to the British isles never mind most of the world
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Post by willj on Sept 28, 2005 12:43:27 GMT
we are native aren't we? we are the product of humans which were cut of when the land bridge was flooded, we have of course been added to since then, but we are native. i think that it is just chance that some if these species didn't reach here. their ancestors would have been in britain before the ice age, and then they retreated or were killed off when the ice age advanced. when it reteated there was still a land bridge for some time and some species crossed it others didn't make it.
wasn't there some speculation that hyla arborea could well have been a native. as they couldn't work out how they got to the New Forest.
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Post by adamanuran on Sept 28, 2005 13:54:09 GMT
Pure and simple release!!! I can't remember who did it but they were 2 adult men!
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Post by richardfrog on Mar 22, 2015 12:08:18 GMT
I think the problem with breeding is our cool summers due to the winds onto our islands from the atlantic. Southern Sweden, Poland and Ontario are much colder than us in the winter but this does not matter as herps are asleep. In summer the temperatures in these places are warmer than here so eggs have shorter incubation times and more reliable hatching.Estonia is the same latitude as the Orkney islands but has, natterjack, sand lizard, smooth snake and pond turtle. Our common reptiles are all viviparous except the grass snake which cheats by using the heat from rotting vegetation , manure etc.
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