story of female SL2

[Daniel Kane]

That is an interesting story, and a shame that you had to find her like that. Have you seen any of her offspring again?

The first adder I found (F1, about 65cm TL) at my closest site in May 2009 I have not seen since September 2010... I am hoping that somewhere she is still alive and that she has just been a bit shy for the last 2 years!

[Daniel Bohle]

Based on my observations the chance to see this female again is not zero

From 2006 to 2011 I counted 17 females (with double counts if that happend twice to the same female) that I was not able to see for one year, 5 for two years and a single one for three years. While in the same time I just counted 5 males that I was not able to find for one year and 1 male for two years. These few male where of course never males that I knew very well. This means, if you can´t find a well known male in spring the chance that this male is still alive is close to zero while its not problem if you cant find a female for one season and mabye two years if she needs 2 years to recover from reproduction.

Data based on a population size of around max. 200 adult animals.

[Daniel Kane]

I think it's great that little studies like this are going on all the time, by many different people with a passion, and that you don't have to be a pro to make some interesting observations on behaviour. How did you estimate the population size, Daniel?

[Daniel Bohle]

I don´t estimate, I simply count them.
To estimate something like a vipera population is not easy
In my mind it makes sense if you don´t have much time and if you just want to have a housenumber of the population size.
But if you visit your area regulary, counting is way more precise than "any" estimation. People can do that and it´s for sure interesting to play with numbers but I failed while trying it. Too many factors that don´t fit and it takes incredible much time with my type of data I still think counting is by far more realsitic for my case than a hand made estimation.

For example. If I count in 2009 exact 100 animals after visiting the spot 50 or more times all over the year, I say 100 animals + a few I was not able to find.
How much is this + ???
Well, you can answer that the next years more precise. Because for example in 2010 and 2011 most probably I find a hand full of animals that I allready knew from before that I was not able to find in 2009. So I can say population size is around 105 + a few more that are still hiding from me. So lets say populations size is abour 110 animals +- a few. Who cares if 119 would be the number or just 106 and if they are 134 in real - even better

[Daniel Bohle]

Today I found the time (or better I spend the energy) to make habitat pics of nearly all of my ~30 known spots from population A.
too bad that I haven´t done this in 2006 at the same time of the year
but now its too late I guess

the weather today was quite good but for some reason it was a poor day with just 5 observation in population A. i drove to population B to see if I get the same bad result and yes...just one.
so I drove home to take care about my ladis

attached the hibernaculum of SL2.