Macedonia in April - questions on ursinii & the island

[Kristian Munkholm]

I am juggling calendar & budget looking at options for a spring trip and Macedonia, perhaps crossing a border or two, April 20-24, looks like a good bet.

I do have a couple of questions in advance, though (If I decide to go, I'll have plenty more...), hope someone will be helpful.

First, ursinii would be among my main targets but - given the altitude - might I be a little early in the season for them? Also, compared to other ursinii populations I've found rather few reports from Macedonia. Is the population struggling more than others?

Second, the island, of course I'd want to go but I've read reports / heard rumours snake numbers have collapsed in the last 5-6 years. Anyone know anything about this?

Thanks in advance for any replies

[Berislav Horvatic]

First, ursinii would be among my main targets but - given the altitude - might I be a little early in the season for them? Also, compared to other ursinii populations I've found rather few reports from Macedonia. Is the population struggling more than others?

I think you should contact the local expert, Bogoljub Sterijovski from Skopje:
https://www.researchgate.net/profile/St ... i_Bogoljub
BTW, the ursinii in Macedonia have recently become quite an interesting and unexpected "riddle", so count on that.
(I mean, maybe the local researchers might keep some details of THAT to themselves, for the time being... They'll
probably tell you where to find them, but not WHAT they are or might be... Unless you make friends with them and
be recognized as a potential coworker.)

Second, the island, of course I'd want to go but I've read reports / heard rumours snake numbers have collapsed in the last 5-6 years. Anyone know anything about this?

Which particular island do you mean? Golem Grad?

[Kristian Munkholm]

Thanks for the reply and the link, Bero - many interesting papers there as well.

In reference to the island, some people around here are a bit touchy about public sharing of detailed locality data, in some cases seemingly even in the case of already well publicized, easily accessible such. To avoid unnecessarily stepping on anyone's toes or worse by making too much of a habit of explicitly naming localities at some point accidentally betraying someone's trust I tend to be cautious about my references, opting here for the "easily identifiable to anyone in the know" style even if it may seem a little silly.

[Berislav Horvatic]

... opting here for the "easily identifiable to anyone in the know" style even if it may seem a little silly.

But Golem Grad has become quite a widespread and public legend, no need (any more) to "protect" it
in this way... (Anyhow, HOW MANY islands are there in Macedonia...?)

[Edvard Mizsei]

(Anyhow, HOW MANY islands are there in Macedonia...?)

Very good question!

First, ursinii would be among my main targets but - given the altitude - might I be a little early in the season for them?

Regarding to ursinii, I think you have very little chance to find them in that early time. There will be lot of snowfield and cold weather, and probably the access to the elevated part of the mountains is also will be covered by snow... You should check the situation of previous years by Google Earth.

[Daniel Bohle]

we tried ursinii a few times end of april...
29.4.2007 in montenegro
25.4.2008 in france
26.4.2009 in italy
30.4.2011 in france
and never failed.
we had really hot but also really cold and stormy weather with and without sun.
sometimes we found one in a week, sometimes we found so many at a single morning that we left the boring place

So I dont think a week before is the point.

in a good year it can work, in a bad year even 3 weeks later can be too early.
whatever, I would not call this "very little chance"

[Berislav Horvatic]

... in a good year it can work, in a bad year even 3 weeks later can be too early.

That's the only real truth about that. But if you try it only ONCE, this spring, there's no statistics to
help you, by definition of statistics vs. probability vs. a single attempt...
As mathematicians like to point out: if you board an airplane, what's the probability to survive the
flight? 50%, of course - either the plane (this particular one you boarded) will crash or it won't...
(No, I'm not joking, and neither are the experts in probability theory - it's one of their professional
"nightmares"... or still hot discussion topics. May G/god help them with that... and us, as well, as
the "users".)
Excuse me, please, for being "off-topic" once again...

[Edvard Mizsei]

... in a good year it can work, in a bad year even 3 weeks later can be too early.

That's the only real truth about that. But if you try it only ONCE, this spring, there's no statistics to
help you, by definition of statistics vs. probability vs. a single attempt...

OK, there is no very little chance, but I think is not the best season for searching a montane species.

May be OFF too... Statistics and probabilities: we were thinking how to deal with suitable localities where no Greek meadow vipers were found so far.

"We estimated the detection probability of Greek meadow vipers by tracking the movements of observers in potential habitats using GPS receivers as the searches were being made. We recorded track length, as well as the number of individual meadow vipers found on each track. To test how track length predicts detection probability, we used a generalised linear mixed model (GLMM) with binomial error distribution, constructed in R. Presence-absence data was used as the binary dependent variable, while the length of track was included as fixed explanatory variable. Observer and locality (mountain) were included in the GLMM as random factors to control for the non-independence of observations in these categories.

In total, we caught 78 vipers and collected 33 shed skins from eight different locations. During the field surveys, the observers covered a total of 457.2 km by walking. The probability of detecting at least one individual (or shed skin) increased with track length (GLMM, n = 146, Z = 3.62, P = 0.0003). Detection probability reached 50% after 4.9 km distance covered by a single observer on one track. In localities where no meadow vipers were found, track length was only 3.3 ± 0.45 km (mean ± SE, n = 7 tracks) due to logistical or weather constraints, and so the detection probability predicted for this distance was only 42.0%.

The fact that we did not detect V. u. graeca on three of the 11 mountains does not necessarily mean that the subspecies is not present there. Usually, perfect detection of a secretive snake species is not possible during short visits. Our analysis of detection also suggests that our effort was insufficient to exclude viper occurrence (or confirm viper absence) at these locations, thus, further field surveys at these sites are needed in order to confirm the presence or absence of populations." (Mizsei et al. in press.)

[Kristian Munkholm]

Again, thanks for all the replies.

But Golem Grad has become quite a widespread and public legend, no need (any more) to "protect" it
in this way...

I suppose you're right - just seemed to recall someone expressing concerns in relation to an earlier thread mentioning it, so I exercised perhaps excessive caution.

Btw. probably the best available answer to my question regarding it was found in one of Boguljub's papers available on ResearchGate

...and back to ursinii...

To conclude, if I go I must be prepared to risk facing a wall of snow forcing me to turn back before I even start searching. Should I be lucky and conditions seem good I must be prepared to walk, walk, walk and walk a little more, still with no guarantee of success.

Sounds like herping, I think I'm up for it

Oh, and Edvard, you wouldn't happen to have data on time spent searching as well as distance covered?

It would be interesting to see if there was an even closer correlation between time spent in habitat and success than distance covered and success. Likewise, it would be interesting to see if anything could be concluded about the optimal search speed. Moving too slow likely covers too little ground, moving too fast might cause you to miss more snakes along the way.

[Berislav Horvatic]

To conclude, if I go I must be prepared to risk facing a wall of snow forcing me to turn back before I even start searching. Should I be lucky and conditions seem good I must be prepared to walk, walk, walk and walk a little more, still with no guarantee of success.
Sounds like herping, I think I'm up for it

If this be so, then I most sincerely wish you a very good luck with everything. Nothing more to say.

Except, to quote Boge: "The Bistra Mountains are part of the Scardo-Pindic group of Mountains
and extend through the western parts of Macedonia. The highest peak is Medenica with 2163 m
a.s.l. ... The habitat of Vipera ursinii populations from the Bistra Mountains is situated between
1650-1900 m a.s.l. (approximately)." Sapienti sat, I would say - regarding early spring.