Some observations, province of Friesland, Netherlands, 2015

[Jelmer Groen]

Hi all,

Here is a selection of pictures I took during fieldwork in the Netherlands. They show some of last year’s observations. All pictures we’re taken in the Dutch province of Friesland.

Vipera berus, male



Vipera berus, female



Vipera berus, female



Vipera berus, mating behaviour



Vipera berus, juvenile



Vipera berus, stillborn/deformed.





Vipera berus, female suffering from the effects of dystocia (retention of follicles)



Vipera berus, same female, more than 6 weeks later.....



At the beginning of March 2015 last year some pyromaniac thought it would be interesting to start a fire in one of the areas where I carry out fieldwork. Around 68 acres of heathland was burned. Last year I have been monitorting the effects of this fire on the population of adders that live in this area and I will continue to do so next year. The pictures below show some adders after leaving their hibernaculum, three days after the fire took place.







Zootoca vivipara



Zootoca vivipara, melanistic





Coronella austriaca



Coronella austriaca, juvenile



Natrix natrix, male



Natrix natrix eggs, uncovered by (probably) a badger (Meles meles).



Anguis fragilis, a pretty rare sight here...



Thanks for watching,

Jelmer

[Frédéric Seyffarth]

Some really really nice shots!
I love vipers but i have to admit that this melanistic vivipara is my favorite!
Thanks for sharing.

[Mario Schweiger]

nice serie of pictures!
the 2 berus on the burnt heatland look fine and easy to observe.
I know how hard it is to spot them in a "green" heatland (in my research area)

Mario

[Jelmer Groen]

Some really really nice shots!
I love vipers but i have to admit that this melanistic vivipara is my favorite!
Thanks for sharing.

You're welcome! I like the melanistic Z.vivipara too. I don't see them that often around here.

nice serie of pictures!
the 2 berus on the burnt heatland look fine and easy to observe.
I know how hard it is to spot them in a "green" heatland (in my research area)
Mario

Thanks Mario! The two V.berus we're pretty easy to spot indeed. During the first weeks after the fire took place I found more adders than usual, simply because there was little cover. Not a single one was dead or injured.

Jelmer

[Berislav Horvatic]

Not a single one was dead or injured.

Not a single one YOU FOUND was dead or injured... The dead ones you were not likely to find, as
they had probably suffocated underground, as the fire passed over their shelters. Sorry for being
... never mind. But that's how it goes - in case of a general disaster (like a wildfire), the snakes
just don't RUN AWAY, they take to the nearest underground refuge instead, and then...

[Jelmer Groen]

Not a single one YOU FOUND was dead or injured...

That's what I said. “Not a single one” off course refers to the adders I found. I was simply responding to Mario's words regarding the fact that the two berus in the burned heath land look fine (healthy?) and easy to observe. It's really not that uncommon to find dead or injured snakes after a (wild)fire.

But that's how it goes - in case of a general disaster (like a wildfire), the snakes just don't RUN AWAY, they take to the nearest underground refuge instead, and then...

...and then....some might get smoked out of their burrow or not make it to a refuge at all? Although I think you're right about most fatalities occurring below the surface, the immediate effects of a fire depend on different factors.

In this particular case the weather was bad (rain, strong wind, 8 degrees Celsius), so most if not all snakes were hiding below the surface. In fact, most snakes were still hibernating (beginning of March). Because of the strong wind the fire spread really quick and didn't affect the surface as much as it could have. Data which have been collected so far suggest that this resulted in a relatively high survival rate.

Jelmer

[Berislav Horvatic]

Because of the strong wind the fire spread really quick and didn't affect the surface as much as it could have. Data which have been collected so far suggest that this resulted in a relatively high survival rate.

Extremely glad to hear that - it's certainly the most important aspect.

[Jeroen Speybroeck]

Data which have been collected so far suggest that this resulted in a relatively high survival rate.

Couldn't this be biased because they're more or less forced to come out?

[Berislav Horvatic]

Data which have been collected so far suggest that this resulted in a relatively high survival rate.

Couldn't this be biased because they're more or less forced to come out?

Forced by what? In any case, only those that did survive.

[Jeroen Speybroeck]

Data which have been collected so far suggest that this resulted in a relatively high survival rate.

Couldn't this be biased because they're more or less forced to come out?

Forced by what? In any case, only those that did survive.

By a destroyed habitat.