Some pictures from the Cres-Lošinj archipelago

[Massimo Trentin]

Anyway,these two islands are a real reptiles paradise...so many species in a so little space isn't that common anywhere else (at least in Europe) .
Lets' hope they'll stay like this as long as possible.

[Ruggero M.]

Here is really too warm now, but this is good for what I call "night safari": in fact we found two Telescopus on a road where I found a dead specimen during the day. Two beautiful encounters also in the late afternoon of yesterday, near the same place where, days ago, I saw the Malpolon pair: at first a big quatuorlineata crossing the road in front of our car, and, while we were watching at this snake, another big snake crossed the road a few meters away from us: this time it was a black aesculapian! Both specimens were males. During the hot day we could only spot (besides the usual quatuorlineata) many Natrix natrix in our known pool, one of which trying unsuccessfully to swallow from one leg a frog. And, just after sunset, a second baby situla, the day before yesterday.

[Berislav Horvatic]

... and totally absent only in these two islands...quite odd . What do you think about it?

Herpetologists visiting the Adriatic islands have always been puzzled by the “surprising” absence of Vipera ammodytes from the
Kvarner islands of Cres and Lošinj. However, a brief glance at the available distribution data reveals that this particular absence
should by no means be regarded as surprising, on the contrary – the absence of V. ammodytes from the Adriatic islands is rather
a rule than an exception. Here are the numbers:
Along the eastern Adriatic coast there are
725 islands and islets (66 of them inhabited),
426 "rocks" (permanently above the sea level),
82 "reefs" (more-or-less at the sea level),
which makes it “a coast of thousand islands” indeed...
Vipera ammodytes has so far been found/recorded on only eight of them, viz. on Sveti Marko, Krk, Pag, Vir, Brač, and Hvar (in abundance on all six), Korčula (in traces) and Mljet (a single find in 2008, still unconfirmed, much as we tried).
So, if one counts only the islands and islets proper (reasonably leaving out the rocks and reefs), the presence of V. ammodytes
has been recorded on a really tiny fraction of them, 8/725, which makes a little more than 1%. That means the absence from
the islands amounting to almost 99%, to the present knowledge.
In view of that, why actually so much "fuss" about the absence of V. ammodytes from the islands of Cres and Lošinj in particular?
What's so much "particular" about them? Why nobody seems to be "troubled" by the absence of V. ammodytes from, e. g., the
Kvarner island of Rab? A rather big island, close to the coast, located between Krk and Pag (both with V. ammodytes), offering
an ideal habitat, the same as the two surrounding islands do... but no V. ammodytes there.
Of course, the above statistics reflects just the present state of our knowledge, which is presumably quite incomplete. But even
doubling or tripling the number of islands inhabited by V. ammodytes would push the above fraction up to only 2% or 3% of them.

After all, what's so terribly special about V. ammodytes? Nobody seems to be "troubled" by the absence of, e.g., E. quatuorlineata
from the island of Pag... although it's present everywhere around it, and Pag is not a small island, and is very close to the mainland...

[Berislav Horvatic]

Looking on nautical charts, Cres-Losinj seems, it has been longer connected to the mainland (Istria) than Krk island.
Sea depth between Istria and Cres has a maximum of 52 meters, mostly between 46 and 48 meters, nearly over the full length.
Sea depth between Cres and Krk is at lest 68 meters and between Krk and the mainland in the east at least 58 meters.
40 meters depth for less than 1 km east of Voz (NE Krk).
Therefore, ammodytes reached the area to late after the last glacial, is no good explanation.

Don't see why it shouldn't be. Imagine the following scenario, in full accordance with the (present) sea depths
and what (very little!) we know about the dynamics of the "flooding" of the Adriatic basin after the latest
(actually quite puny!) glacial maximum:

Vammo advances/spreads to the northwest from its South Balkan refugium, along the eastern Adriatic coast,
while at the same time the sea floods the Adriatic basin... In a quite real sense, it's kind of a race - who gets
first to particular sites, Vammo or the sea? (And remember, Vammos are rather slow when it comes to moving
anywhere around, let alone migrating large distances...)
Around 11 000 years before present (b. p.) the sea level was about -50 m (with respect to the present one),
Cres/Lošinj and Krk had already been separated by a sea channel, but Krk was still attached to the nearby
mainland, and Cres/Lošinj as well (to Istria). Both were still peninsulas.
Vammo reaches Krk "in the last moment", just before it separates from the mainland and becomes an island.
Vammo proceeds spreading further to Istria and reaches its northern parts. It's quite a long way, all around
the northern part of the Adriatic basin - now already "flooded", and it takes time... Too much time to reach
Cres/Lošinj still as a peninsula of Istria, instead of newly-born islands...
Cres/Lošinj separate from Istria and become islands before Vammo reaches those parts. (Actually they had
detached slightly before Krk did, but it doesn't matter, as all this happened within a (relatively) very short
time, maybe just some 500 years. The rate of "flooding" - the increase of the sea level - was at its maximum
at the time, it was quite a "dramatic" period of rapid change...)
BTW, at around 11 000 years b. p. Rab was already an island, while Pag and Krk were still peninsulas. So, no
Vammo on Rab... On its spreading towards the north it inhabited the peninsula of Pag, skipped the island of
Rab (what else could it have done...) and reached the peninsula of Krk just in time. But for the Cres/Lošinj
peninsula, so far away, it was already too late... For Istria it was not, as it has remained a peninsula till the
present day.
And that's just what one observes today - both the islands and the distribution of V. ammodytes on them.
So, what should be so wrong with an explanation like that?
Of course the "model" is extremely crude - it relies just on the sea depths encountered today and doesn't take
into account the possible changes of the sea bed itself. At least the mighty river Po with its sand deposits could
have either "sank" or "raised" the sea bed, at least in the Northern Adriatic, and the river Neretva could have done
an analogous mischief in the Central Adriatic... But let's leave that to the dedicated experts who earn their daily
bread solving "additional complications" like that... making their doctoral dissertations, scientific papers,... Let
them live. (After having spent almost a month trying to understand all these "additional complications", I decided
to just give it up and leave all that to THEM. Maybe one day someone writes a "definitive" and clear review paper
on "all that"... Till then, I'll just stick to this oversimplified hypothesis of mine.)

Maybe, it is the presence of Malpolon on Cres island.

As far as I know, Malpolon insignitus and Vipera ammodytes do not exclude each other anywhere else.
On the contrary.

[Ruggero M.]

I've so many pictures about what I've already told... I will post now only a small selection of these.

A big Malpolon male, light blue-greenish in colour, spotted in the late afternoon of my arrival day on the island: by the shape of its body, I think it had recently ingested a prey (probably a Lacerta bilineata)

In the same stone wall, a few meters away, onother more bluish coloured male was active during those days, and searching for prey among stones and near my feet!

A couple of kilometers away, other Malpolon were active in the same area, and I could observe a pair together in the same shelter. The female was very shy, and, at first, I suspected its presence only from the noise it produced: later I could watch it, with big surprise, in the pictures I took to the male...

Here is the "dominating" male from a certain distance

The female is present, but impossible to see with this picture

More detailed pictures of the male

[Ruggero M.]

Here you can see also the female... watching at me!

The body of the male is visible low on the right, the head of the female on the upper left of the picture

Here you can clearly see that the heads belong actually to two different snakes...

The "dominating" male was really not very shy, and if I stayed motionless, it could simply crawl among my feet

[Ruggero M.]

[Ruggero M.]

A smaller male arrived into the "territory" of the bigger male.

Here is the "intruder"

And here you can see both the males

After this picture, the bigger male saw the "intruder", crawled towards it, and the smaller male run away very quickly.

Other two "rare" (and horrible...) pictures of the very shy female

Head and part of the upper body (while the lower body of the male is on the right side)

FEMALE BODY.jpg (162.84 KiB) Viewed 5777 times

Head detail

[Ruggero M.]

A totally different place, in the center of the island

A beautiful light bluish male, captured while running away from the pathway

A female, taken in the hand for a picture

[Ruggero M.]

Fourlined snakes...

A bad tempered female began to "hiss" as soon as it noticed my presence.
I met the same female another day, at a short distance from where I saw it the first time, and I recognized it again for its aggressive behaviour.
But it never bit me, even if I took it in the hand once.

Here is the female

A different day another female was present in the same exact place, and at first I thought it was the same female.
Here is the "other" smaller female

But a few meter away I met the "aggressive" female again: it escaped near a stone cover, and began its intimidatory behaviour as usual...