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Last weekend we again visited Solling area, Germany to look for the salamanders there! After some dry and hot weeks, this saturday raining nearly the whole day
So already in the afternoon we could see more then 70 Salamandra on the way an nearby - very fast running around!
What I never saw before, lots of them tried to climb the trees - any idea why?




juvenil:


This one was the craziest - climbed on the old road, about 30 cm above the ground


more photos: https://www.flickr.com/photos/salamanderseiten/albums/72157670707173944
Paul

Nice manders!!!

Interesting question too! At my spot, at least some animals do this every time the conditions are at their best. I have been taking notes of this behaviour and I do have some hypotheses.

1) One reason could be to soak in moisture that runs down to the forest floor along the trunk of the trees. In this time of year, leaves have not yet fallen. So, when it rains, these tree trunks are "waterways" in a rather dry forest floor environment, especially after long periods of drought.
2) Another idea would be that a lot of potential food items are also crawling around on tree trunks.
3) Finally, especially males do this. Climbing a tree or sitting on top of a tree trunk, is a more 'extreme' form of their typical push-up behaviour, looking for a mate. Higher up, they are more likely to detect females (be it by sight or by feromones).

Below is some illustration from my data, which I made especially for you.

First a frequency distribution of the number of visits, showing that there is a higher proportion of visits without climbing females than without climbing males. Also, there are several visits with >10% climbing males, while only one with >10% climbing females.



If we look at the distribution per month and per sex, it becomes again obvious that (a) there's a lot of zeroes (meaning that visits without climbing animals are common), (b) males climb more often and (c) there's a bit of a hint of a seasonal pattern in it.



The many zeroes cloud the image, though. I could show a graph of how the degree of push-up behaviour varies across the seasons and between the sexes.

Here it is. Stronger pattern, both in terms of season and sex.

Thanks Jeroen,
interesting considerations - could well be possible.
Great illustration
Paul

Interesting !