Ilian Velikov wrote:Jeroen Speybroeck wrote:The fact that the smaller one seems to be climbing up, is a bit of a brainteaser too. Salamanders are found quite often climbing the lower tree, even up to half a metre above the forest floor. Tree trunks may channel rainfall to the forest floor, so a salamander seeking moisture may like to mount the tree base. Or is it the ample food items (like harvestmen, woodlice, spiders, slugs, ...) that can often be found on the lower part of the tree trunk which lure them up the tree? Females do it too, so sniffing up pheromones may not be the answer. What do you think?
Even though trees channel rain water I think the leaflitter would still be much more moist than a tree trunk. After all the trees channel the water to the ground. The more logical thing if seeking moisture for me would be to bury in the leaflitter. Could it be warmth? You mentioned temperatures are low and even a few centimeters above ground would be slightly warmer. Also in winter wood/tree bark always seems to be warmer to the touch than other natural materials such as stone, mud, leaves, etc.
Interesting discussion!
My friend, Andreas Pix, and I found 16 Salamandra s. terrestris outside on a warm wet day in spring (26 April 2013) in central Germany (Hann. Münden). Many of them tried to climb up tree trunks. Temperatures were above 15°C, so I would not buy the temperature hypothesis.
As a historian, I tend to believe in some atavistic behavioral pattern rather than in funtional explanations.
I add pictures of evidence, though there is more material, including videos, if somebody is interested.