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

[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