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Re: It's always worth it to go out (for Salamandra) ;-)

PostPosted: Tue Nov 27, 2018 1:46 pm
by Ilian Velikov
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.

Re: It's always worth it to go out (for Salamandra) ;-)

PostPosted: Tue Nov 27, 2018 7:08 pm
by Rafa Carmona
Two weeks ago I observed for the first time the climbing activity of the Salamandra salamandra morenica in Seville. The animal was about one meter tall on a Pistacia lentiscus.

Re: It's always worth it to go out (for Salamandra) ;-)

PostPosted: Tue Nov 27, 2018 7:42 pm
by Jeroen Speybroeck
Haha, great, Ilian! I left that out because I wondered if anyone would come up with it. :D
Bufo bufo also does this climbing, also way outside of the breeding season.
But it's just a theory so far...

Re: It's always worth it to go out (for Salamandra) ;-)

PostPosted: Thu Nov 29, 2018 12:51 pm
by Ilian Velikov
Jeroen Speybroeck wrote:Haha, great, Ilian! I left that out because I wondered if anyone would come up with it.
Bufo bufo also does this climbing, also way outside of the breeding season.
But it's just a theory so far...


Thanks :) Both species are found around my property here, so I'll keep an eye for this behavior next season (-4 C with 15 cm snow right now :? )

Re: It's always worth it to go out (for Salamandra) ;-)

PostPosted: Sun Dec 09, 2018 10:02 pm
by Ilian Velikov
Last week there was a considerable amount of snow fall here accumulating to around 15-20 cm, and very low temperatures reaching to -11 C at night and early morning and -6 C during the day. This was followed by a warm spell in the last 2-3 days with sun and temperatures climbing to 8 C during the day. This has almost entirely melted the snow except for some small patches at the shadiest of spots. These spring-like conditions have apparently triggered the breeding of the fire salamanders because today we found at least 10-12 larvae at our breeding site (a small shallow pond, around one square meter, with running water at a local spring). Most certainly there will be more cold weather and more snow until spring time, so it would be interesting to see how (and if) the larvae cope. Does anyone have any information on larvae survival abilities in this conditions?

P.S. The water is constantly running and never freezes at this spot.

Re: It's always worth it to go out (for Salamandra) ;-)

PostPosted: Mon Dec 10, 2018 9:01 am
by Alexander Pieh
Dear Ilian,
I have no doubt that the larvae survive (if nothing else happens like predators…).
This is a common situation in a spring here (for example Ludwigsburg / Baden- Württemberg).
The water in springs keeps nearly the same temperature during the year.
Some years ago, I have tested if the larvae eat during the short-day period (>9h daylight).
I tested it positive with a Lumbricus. It seems that the larvae have no time of inactivity (hibernation) during winter.
Gammarus, Ephemeroptera etc. are also active during the winter season while predators (for example Austropotamobius torrentium ore Natrix) are less active/inactive.
At last under the described condition winter might be the better season for Salamandra larvae.
The Best
Alex

Re: It's always worth it to go out (for Salamandra) ;-)

PostPosted: Mon Dec 10, 2018 1:46 pm
by Ilian Velikov
Thanks Alexander! Yes, this makes sense. I should have thought that water temperature at a spring should not be affected much by the air temperature.

Re: It's always worth it to go out (for Salamandra) ;-)

PostPosted: Mon Dec 10, 2018 3:52 pm
by Jeroen Speybroeck
Yes, larvae can survive in running and/or groundwater-fed waterbodies, as/if it offers stability in water temperature. Not too sure if growth doesn't slow down, though, as this also involves metabolic optimal temps, and as such is somewhat more complex that "eat or not eat" question. However, I have seen them also go to waste in car tyre tracks, both due to desiccation as well as frost, so at least some mothers just risk it, hoping that rain and no frost might add a little recruitment bonus to the population.

Re: It's always worth it to go out (for Salamandra) ;-)

PostPosted: Tue Dec 11, 2018 2:24 pm
by Alexander Pieh
In a source for spring water (near Nagold) which was closed with a cap, one of the locals showed me the largest Salamandra s. t. larvae I have ever seen. The water was very cold. I believe food was rare also in this place (Gammarus and maybe younger S. larvae).
It is well known that some animals in streams (for example Gammarus) swim permanently against the streaming to compensate the drift (so you can even find them in caves). I´m quite sure that S. larvae do the same (high density in spring sources or near to them, small cave in Südtirol with S. s. s. larvae). This means cold water even in summer. Also, I have kept some S. larvae under different temperatures.
From these observations and without a scientific proof I would speculate that cold (oxygen rich) water allows the larvae to feed for a longer time on water organism and to grow larger until they metamorphose. This might be an advantage if they change into the land habitats.
So, it might be an advantage to release the larvae in winter.
I know the hypothesis is only monocausal with a lot of question marks.
-What is the metabolic optimal temperature to grow when for example food is limited / not limited?
-Is a larger size better than a faster metamorphosis? – depends on predators in the water / terrestrial habitat etc…
However, worth to think about it.

Re: It's always worth it to go out (for Salamandra) ;-)

PostPosted: Tue Dec 11, 2018 4:44 pm
by Ulrich Schulte
Hello Alex

this brings a new paper to my mind:

https://www.researchgate.net/publicatio ... ia_Urodela