RAUK - Archived Forum - t alpestris/brit newt contrasts/compariso

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t alpestris/brit newt contrasts/compariso:

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ben rigsby
Senior Member
Joined: 27 Apr 2010
No. of posts: 337


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Posted: 11 May 2010
a newt nerd writes,
just like herp author t beebee, i too have t/m/i alpestris specimens (a few) in my pond. along with the 3 native species.
i agree with current thinking that TA is probably not a threat to our own herp fauna. at least forseeably.

ive noted,

food gathering-wise, alpestris doesnt seem to compete much with helveticus/vulgaris in the upper echelons of the water. it rarely darts after prey and is a sluggish, bottom dweller.it walks slowly but purposefully along the floor like an underwater tortoise. quite the opposite favoured feeding strategy to our smaller two species.

but similar to cristatus.

TB is certainly the brit species with which it shares the most habits. such as being shy and primarily nocturnal. and, i would think, the one which it competes with most for food.
if TA is a threat to any ours then its surely TC.

i suspect alpestris eats quite a lot of carrion. ive certainly seen it gleefully consuming decaying worm skin other newts werent interested in. ive seen our 3 species eat remains too but not as commonly.
further to this, its "feed mode" activation response on seeing live prey (even writhing worms) is very slow compared to any brit species and as such it often loses out on a meal to them. it doesnt even take much notice of frog tadpoles which other newts (esp smooth) love and chase heartily.
unlike cristatus though, it will breed readily in most types of water body, large or small including mere tyre tracks (in europe). so its haunts are often different to those of cristatus.

it also lives up to its reputation of being highly aquatic. all year here as far as i can tell. unlike any brit species. ive yet to find one on land. juveniles are in my pond too. again, unlike the native efts which leave the water until maturity.

happily, t alpestris would be easy to spot if they do spread more in the uk and removal is deemed necessary- their appearance being unmistakeable when compared to any brits and easily identified even by a beginner.

on the whole my impression is that TA can probably "get along" with our natives in ponds where it co-exists owing to its own little specialisations/disadvantages which lead to a less competitive ecological niche.

and after all, it lives along side our natives in europe quite happily.

thanks for listening (if youve got this far!) and hope i havent bored you.
well done!

alien introductions dont always end in a red squirrel/grey squirrel disaster.

thoughts, comments welcome

ben
Diversity.
Suzi
Senior Member
Joined: 06 Apr 2005
No. of posts: 860


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Posted: 11 May 2010
I'm not an expert but my opinion is that it is dangerous to justify introductions which seem fairly benign and occupy a niche slightly different to our natives.
Trying to remove them at a later date is always harder as you definitely wouldn't get them all however distinct they look.
You say it is more amenable to varying breeding sites. Again a clue to how successful it might become?


Suz
ben rigsby
Senior Member
Joined: 27 Apr 2010
No. of posts: 337


View other posts by ben rigsby
Posted: 11 May 2010
hi suz. i think my tone was misunderstood. i wasnt trying to justify introductions, but merely saying that if they are here to stay, it doesnt NECESSARILY have to be at the expense of our natives.
and compare some behaviour between the species into the bargain.
you could get them all later if you were determined enough though i dont think therell be a need unless illegal introducing becomes much more frequent;you can easily buy TA on-line its true but theyre not as readily available as many herps and demand is probably low since most herp buyers dont want newts.although obviously people that do remain a threat thru the unwanted pet discarding/deliberate introduction routes.
i caught and removed an entire lizard colony (100s)single-handedly as a boy (which i regret)and the passenger pigeon (once the worlds commonest bird) was shot to extinction in only a few years.


thanks for your thoughts and hope ive cleared things up!
ben

ben
Diversity.
Suzi
Senior Member
Joined: 06 Apr 2005
No. of posts: 860


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Posted: 11 May 2010
Thanks Ben. I wasn't critising you, just trying to say something that seems fairly innocuous towards our own species might end up taking over their niches.
I must say that when I saw the wall lizards on Portland a few years ago I thought they were delightful - colourful, easy to see, not timid and lots of them. I know they are introductions but I can see the attractions !

Suz
Alex2
Senior Member
Joined: 16 Dec 2006
No. of posts: 266


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Posted: 12 May 2010

[QUOTE=ben rigsby]a newt nerd writes,
just like herp author t beebee, i too have t/m/i alpestris specimens (a few) in my pond. along with the 3 native species.
i agree with current thinking that TA is probably not a threat to our own herp fauna. at least forseeably.

ive noted,

food gathering-wise, alpestris doesnt seem to compete much with helveticus/vulgaris in the upper echelons of the water. it rarely darts after prey and is a sluggish, bottom dweller.it walks slowly but purposefully along the floor like an underwater tortoise. quite the opposite favoured feeding strategy to our smaller two species.

but similar to cristatus.

TB is certainly the brit species with which it shares the most habits. such as being shy and primarily nocturnal. and, i would think, the one which it competes with most for food.
if TA is a threat to any ours then its surely TC.

i suspect alpestris eats quite a lot of carrion. ive certainly seen it gleefully consuming decaying worm skin other newts werent interested in. ive seen our 3 species eat remains too but not as commonly.
further to this, its "feed mode" activation response on seeing live prey (even writhing worms) is very slow compared to any brit species and as such it often loses out on a meal to them. it doesnt even take much notice of frog tadpoles which other newts (esp smooth) love and chase heartily.
unlike cristatus though, it will breed readily in most types of water body, large or small including mere tyre tracks (in europe). so its haunts are often different to those of cristatus.

it also lives up to its reputation of being highly aquatic. all year here as far as i can tell. unlike any brit species. ive yet to find one on land. juveniles are in my pond too. again, unlike the native efts which leave the water until maturity.

happily, t alpestris would be easy to spot if they do spread more in the uk and removal is deemed necessary- their appearance being unmistakeable when compared to any brits and easily identified even by a beginner.

on the whole my impression is that TA can probably "get along" with our natives in ponds where it co-exists owing to its own little specialisations/disadvantages which lead to a less competitive ecological niche.

and after all, it lives along side our natives in europe quite happily.

thanks for listening (if youve got this far!) and hope i havent bored you.
well done!

alien introductions dont always end in a red squirrel/grey squirrel disaster.

thoughts, comments welcome

ben[/QUOTE]

 

Hello Ben,

As a newt fanatic i'm sure you're well aware that alpestris, although highly aquatic (particularly in certain areas of Europe), are also well known for travelling large distances when on land - perhaps Europes most land exploratory caudate (ironically). For that reason, and given that they'll happily breed in literally any body of standing water, my personal feeling is that should the worst case scenario happen, rounding them up would be nigh on impossible. I do think you miss the point when you suggest that alpestris mixing with our natives would not threaten our own species - the reasons for (slight) concern have nothing to do with competition for food nor breeding areas etc.

Cheers

Al


kevinb
Senior Member
Joined: 18 Mar 2009
No. of posts: 61


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Posted: 12 May 2010
Just to add another thought to trhe arguement, the Alpines for sale in shops etc could be wild caught and harbouring parasites or diseases such as chytrid.
ben rigsby
Senior Member
Joined: 27 Apr 2010
No. of posts: 337


View other posts by ben rigsby
Posted: 12 May 2010
thanks al/kev,
i only said might not. what do you think the reasons for slight concern are then al?
and what do you think should be done if anything?
cheers
ben
Diversity.
will
Senior Member
Joined: 27 Feb 2007
No. of posts: 330


View other posts by will
Posted: 13 May 2010
I'm sure I heard one reason for applying the precautionary principle re M. alpestris was a case study in Scotland, in which a GCN pond lost its GCN (rare in Scotland) after colonisation by alpestris.  Of course, correlation ain't causality, and this is a sample of only one site.  It could be that GCN at the edge of their range in the UK could be vulnerable to anything which tips the balance.  I can't remember any more details of the case, though.  Maybe someone has done a study of the relationship between the long-established populations around Newdigate and elsewhere and the local GCNs? 
Vicar
Senior Member
Joined: 02 Sep 2004
No. of posts: 1181


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Posted: 13 May 2010
"Alpine newts are known carriers of the chytrid fungus Bactrachocytrium dendrobatidis. This can cause the disease chytridiomycosis which seriously affects some amphibian species."

DEFRA link

Re Newdigate...It's hard to say how alpestris has affected GCN populations as there are other pressures, such as hybridisation with carnifex
Vicar40311.3273611111
Steve Langham - Chairman    
Surrey Amphibian & Reptile Group (SARG).
Caleb
Forum Coordinator
Joined: 17 Feb 2003
No. of posts: 448


View other posts by Caleb
Posted: 13 May 2010
[QUOTE=Vicar]
Alpine newts are known carriers of the chytrid fungus Bactrachocytrium dendrobatidis.
[/QUOTE]

But what's meant by 'carriers' in this context? Are they 'carriers' like smooth newts (in that the fungus has been found on them), or like american bullfrogs (in that they can spread the fungus without being affected themselves)?

On a completely unrelated note, it's interesting that the DEFRA note uses 'eft' to describe a newt larva- this seems to have become more popular recently. I'd only ever heard 'eft' used for terrestrial juveniles until a couple of years ago.

- t alpestris/brit newt contrasts/compariso

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