fieldherping.eu

Posted: **Fri Sep 16, 2016 9:18 pm**

Ilian Velikov wrote:After a quick glance through these it is obvious that the presence of Trachemys has negative effects on
local turtles but I'm surprised that it happens so quickly - just "a few years" as Berislav pointed out.

Mario showed me his favourite (and the biggest) “emys pond” on Krk on the 29th of May 2005, and we
saw only Emys orbicularis there, even Hannes managed to catch one. Within a year or so, the first
Trachemys scripta elegans appeared. (Or was it already back then? I forget.)
Mario also reported having seen 2 individuals of Trachemys scripta scripta in this pond, I forget when.
Ten years later, this year, swarms of T. s. elegans boldly swimming around like a pack of sharks, and
no E. orbicularis in sight.
As it’s the biggest pond on Krk with E. orbicularis we know of, one can easily imagine that in smaller
water bodies it could have gone even much faster.
Believe it not, but the intruders can use even their greater physical strength to physically drive away
the natives... Imagine a log in a pond, ideal for basking, occupied by a few rednecks enjoying sunshine.
A poor native tries to join them, but one of the rednecks shoves it back into the water, by sheer brute
force, kicking it with its leg. (Related to me by an eyewitness, the herpetologist dr. Biljana Janev Hutinec.)

Posted: **Fri Sep 16, 2016 9:45 pm**

Berislav Horvatic wrote:
Ilian Velikov wrote:After a quick glance through these it is obvious that the presence of Trachemys has negative effects on
local turtles but I'm surprised that it happens so quickly - just "a few years" as Berislav pointed out.

Believe it not, but the intruders can use even their greater physical strength to physically drive away the
natives... Imagine a log in a pond, ideal for basking, occupied by a few rednecks enjoying sunshine. A poor
native tries to join them, but one of the rednecks shoves it back into the water, by sheer force, kicking it
with its leg. (Related to me by an eyewitness, the herpetologist dr. Biljana Janev Hutinec.)

do turtles discriminate between conspecific and allospecific turtles?

Posted: **Fri Sep 16, 2016 9:48 pm**

Michal Szkudlarek wrote:from what i remember alien species of turtles do not reproduce in poland, only autochtonic Emys does

From what I know, Trachemys scripta elegans, unfortunately, does reproduce in Croatia, as well as in
some countries more to the north of it. By "Croatia" I mean the environs of Zagreb, with its continental
climate, not the Mediterranean parts of it, where it would be even more likely.

Posted: **Sat Sep 17, 2016 10:59 am**

Michal Szkudlarek wrote:do turtles discriminate between conspecific and allospecific turtles?

Why shouldn't they? Most animals do, under "normal" conditions. (That is, unless totally overwhelmed
by e.g. a mating frenzy or something extraordinary like that.)
Would you ask whether lions recognize leopards as a different species? And they are both "cats"...

Posted: **Sun Sep 18, 2016 9:54 am**

here a short video with lots of Emys and 2 Trachemys (May, 2008). No competition could be observed. Bero knows this pond on Krk island. Unfortunately they made a vineyard just beside at the last years (seen in May 2015) and only a few Emys have been seen.
http://www.facebook.com/1654533274/videos/10206169306705689/