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This week in Copenhagen, blue esculentus and alien alpestris

PostPosted: Sun Aug 27, 2017 9:01 pm
by Kristian Munkholm
Copenhagen herping is usually pretty uneventful.

This past week, however, a couple of quite surprising critters showed up.

On Tuesday, reports surfaced of a couple of alpine newts being found in the woods on the grounds of a castle in the northern suburbs. Alpine newts are in Denmark restricted to the extreme southeast of Jutland where the northernmost populations in the world appear so of course this had to be an introduced population.

Nevertheless, I was curious.

Pauline has ballet lessons close by so on Thursday after work I drove her to and from. I spent about an hour searching while she was dancing.

Alongside several of the usual suspects, smooth newts, common toads and ditto frogs, I found three alpine newts under cover on the forest floor.

Pretty as they are, the newts were not the most attractive herps of the day. That prize goes instead to an unusually beautifully coloured and patterned slate gray and orange common toad.

My hasty discount cell phone shots do not do the animals any justice.

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The next noteworthy report ticked in Wednesday. A blue edible frog had been found in a lake on the island of Amager.

There was a social event in Gustav's class at a nearby nature center so we decided to stop and see if we couldn't find the frog on our way home.

We had all but given up and were headed back towards the car when suddenly there it was. I don't know how you would label this kind of pigmentation defect but while I often find the freaks of the herp world rather ugly, this was simply gorgeous.

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Re: This week in Copenhagen, blue esculentus and alien alpes

PostPosted: Sun Aug 27, 2017 10:28 pm
by Michal Szkudlarek
Wow. I have never seen patchy blue pigmentation in green frogs before.

Re: This week in Copenhagen, blue esculentus and alien alpes

PostPosted: Sun Aug 27, 2017 11:44 pm
by Ilian Velikov
:o Nice one! The blue green frog is awsome but I also love the Bufo.

Re: This week in Copenhagen, blue esculentus and alien alpes

PostPosted: Thu Aug 31, 2017 11:42 pm
by Tom Hoogesteger
That esculentus looks crazy and that toad is stunning! :shock:

Alpestris was included in Sven Nilsson's "Skandinavisk fauna" (1842), based on two animals allegedly found near Landskrona, western Skåne. The findings were later, however, interpreted by Gislén & Kauri (1959) as misidentified juvenile Triturus cristatus with unspotted bellies.
This just makes me think, maybe Nilsson wasn't wrong after all? Could there actually be some isolated, natural populations further north than currently known? :|

Re: This week in Copenhagen, blue esculentus and alien alpes

PostPosted: Wed Nov 15, 2017 8:23 pm
by Jan Pröjts
That was news to me, that the alpine newt has been found in Copenhagen. I checked the danish site Fugle og Natur and it seems that the new found population is regarded as translocated from somewhere.

Regarding the Swedish side in Skåne, no certain observations of alpestris have ever been recorded here. The only anomaly that I know of except pond terrapins was a lake frog (Pelophylax ridibundus) found washed up on the seashore on the eastern side of Skåne in 1979. Presumably from Bornholm.

Re: This week in Copenhagen, blue esculentus and alien alpes

PostPosted: Wed Nov 15, 2017 11:08 pm
by Kristian Munkholm
Jan Pröjts wrote:That was news to me, that the alpine newt has been found in Copenhagen. I checked the danish site Fugle og Natur and it seems that the new found population is regarded as translocated from somewhere.


Since the discovery stories have surfaced of someone talking 15-20 years ago of having released alpine newts from Harzen in a pond somewhere in that suburb. It is presumed that this event really did occur and established the current population, which seems to be quite healthy. The site is sufficiently isolated that there should be no risk of the population spreading.

Re: This week in Copenhagen, blue esculentus and alien alpes

PostPosted: Fri Nov 17, 2017 4:06 pm
by Berislav Horvatic
Sorry for the poor resolution, not my photos. Lake at Budinščina, Croatia, August 2005.

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valjda kolovoz 2005.jpg
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Re: This week in Copenhagen, blue esculentus and alien alpes

PostPosted: Fri Nov 17, 2017 9:26 pm
by Ruggero M.
I don't know if it's "always" the case in herps which have blue colors, but very often in nature (and I'm pretty sure in those frogs too) the blue colour is due to the so called Tyndall effect: actually only optical effect of pure black pigments.
I'm a dermatologist, and this fact happens also in some melanocitic naevi: the blue colour of the "blue naevus" is given only by deep black melanin in the human dermis...

P.s. (Kristian: publish the pictures of Italy if you'll find the time! ;) )

Re: This week in Copenhagen, blue esculentus and alien alpes

PostPosted: Fri Nov 17, 2017 10:31 pm
by Berislav Horvatic
Quidquid id est, it's always fascinating to find a "green frog" which is so uniformly deep turquoise.
(And quite obviously being one of the "green" species, certainly not a Rana arvalis. After all, it was
in August...)
As far as I know, all the others around the pond were neatly & decently green, of course.

Re: This week in Copenhagen, blue esculentus and alien alpes

PostPosted: Sat Nov 18, 2017 3:11 pm
by Kristian Munkholm
Thanks for all the comments :)

Bero, nice frog.

Ruggero, I'll try to get around to it. Started on a small report when I got home, then left it for a couple of days when I was busy and never really got back to it.

For now, here's a little critter that was posing so nicely on a rock by the side of the path, deserving of a better photographer...

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