Why do snails climb up?

[coyote]

Mr Coyote and I like to go on walks in local parks and wildlife refuges, and we always see a lot of snails wherever we go. We've seen hundreds of them estivating, and they always seem to want to climb up as high as possible.

Sometimes they cover the branches of trees, often up in the very highest branches, in thick bunches like a traffic pile-up; sometimes they are clustered in rock crevices, sometimes up the fenceposts and under the railings of the fences along the trail. I cannot imagine what drives a snail to climb all the way up a tree into its topmost branches to estivate.

Here is a cluster of estivating snails in a dead pine tree.


Some of them climbed right up into the topmost branches of the tree. Why a snail would do this is a mystery to me.


Here are snails clustered around the lid to some kind of storage container in a wildlife refuge.



So, what are the reasons a snail will climb up, sometimes quite far?

Do they climb up to get away from terrestrial predators?

Do they climb up to get away from the heat of the ground?

Some other reason?

[goose]

Not sure of the reasons but snails in the UK also often congregate in huge masses to hibernate or aestivate, they are often sealed in their shells piled on top of one another in crevices or other sheltered spots. Have never seen them high up trees like in your pictures - very unusual and impressive - hope someone with more knowledge has an answer for you.

[Arno]

Coyote,I think you answered your own question already.Snails climb high to escape the worst heat and it also makes them less vulnerable to any predators.

[Buse]

Arno - not to be rude or anything ( obviously lol ) but what about birds because birds eat snails so wouldnt the birds be able to get to the snails easier ??!!!!!!! im confused lol

[apple]

Snails have an hard shell that avoid most atacks from birds. And not all birds can take off the snail, only some like crows and robins: these birds are known to use stones to crack the snail shell. Also an hawk we say it in portuguese « caramujeiro» that lives in the Everglades and in Cuba, eat only aquatic snails,and he use his beak to reach the snail meat.
I agree with Arno it´s mostly to avoid excessive heat or drought and to avoid terrestrial predators.
Very nice pictures Coyote!

[coyote]

Thanks for your replies. Mr Coyote took the pics; credit where it's due!

It's almost like a game Mr Coyote and I play on a walk: look for snails on the branches! On almost every tree we can see them. Even on the underside of park bench seats!

I can understand why they congregate in large masses, but I'm still mystified by why they would go to the effort of climbing all the way up into the highest branches of a tree. It seems they would then make themselves more vulnerable to dehydrating winds and direct sunlight (especially like in that dead pine tree in the pic, without any surrounding foliage to add moisture).

[apple]

Does that place had a flood recently?
Snails climb up in these situations: to reach a food source,to scape from a particular enemy, when the ground is too wet ( I mean with too much water) as well as when it´s too hot and they don´t have places to hide.
If snails don´t have stones or logs to hide below to scape from hot temperatures registered on the surface of the ground, they have to climb up, where the temperatures aren´t as hot.
They can be exposed to the sun, they would be as well if they were on the ground ( if there aren´t any significant fresh shade), with the difference that temperatures in the ground are much higher. So they prefer the trees.

[Buse]

Ooooo I see thanks 'apple'

Yes very nice pictures !

[coyote]

apple said:

Does that place had a flood recently?
Snails climb up in these situations: to reach a food source,to scape from a particular enemy, when the ground is too wet ( I mean with too much water) as well as when it´s too hot and they don´t have places to hide.
If snails don´t have stones or logs to hide below to scape from hot temperatures registered on the surface of the ground, they have to climb up, where the temperatures aren´t as hot.
They can be exposed to the sun, they would be as well if they were on the ground ( if there aren´t any significant fresh shade), with the difference that temperatures in the ground are much higher. So they prefer the trees.

The place in the first 2 pics is in Menlo Park, Calif. (south of San Francisco), in a place called Bayfront Park, right on San Francisco Bay. It is comprised of several hills which are capped-off landfill, covered with some topsoil and landscaped with trees, shrubs, grasses and native wildflowers. There had not been any flooding when the pics were taken (summer); Calif. has dry summers and gets all its rain during the winter and early spring.

That particular location has few stones and logs on the ground, because it is not a natural hill, it is a re-purposed landfill. All stones at that park had to be brought to the site by humans, and the local government did not want to pay people to bring in stones, lol. So in that context, what you said makes sense about the dead tree being the best option for the snails.

Almost all the empty snail shells Mr Coyote and I see on our walks are very pale from being bleached by the sun. The summer sun can be very hot and relentless in this area, but we always see hundreds of snails in spite of it.

[apple]

coyote said:

apple said:

Does that place had a flood recently?
Snails climb up in these situations: to reach a food source,to scape from a particular enemy, when the ground is too wet ( I mean with too much water) as well as when it´s too hot and they don´t have places to hide.
If snails don´t have stones or logs to hide below to scape from hot temperatures registered on the surface of the ground, they have to climb up, where the temperatures aren´t as hot.
They can be exposed to the sun, they would be as well if they were on the ground ( if there aren´t any significant fresh shade), with the difference that temperatures in the ground are much higher. So they prefer the trees.

The place in the first 2 pics is in Menlo Park, Calif. (south of San Francisco), in a place called Bayfront Park, right on San Francisco Bay. It is comprised of several hills which are capped-off landfill, covered with some topsoil and landscaped with trees, shrubs, grasses and native wildflowers. There had not been any flooding when the pics were taken (summer); Calif. has dry summers and gets all its rain during the winter and early spring.

That particular location has few stones and logs on the ground, because it is not a natural hill, it is a re-purposed landfill. All stones at that park had to be brought to the site by humans, and the local government did not want to pay people to bring in stones, lol. So in that context, what you said makes sense about the dead tree being the best option for the snails.

Almost all the empty snail shells Mr Coyote and I see on our walks are very pale from being bleached by the sun. The summer sun can be very hot and relentless in this area, but we always see hundreds of snails in spite of it.

Very interesting descriptions.
That climate sounds similar to here, i.e, mediterranean. dry summer, most rain usually in the winter, spring/autumn could be rainy or dry.
I would guess the snails on the pictures are Otala lactea ( an introduced specie) ... Maybe I´m wrong..

[coyote]

Most of the shells have their markings bleached out so much that I felt discouraged trying to identify the species. The lip is light and the columella is dark, like a deep chocolate brown. I wasn't sure if they might be Cepea, because of the stripes. There are a lot of introduced species in this area.


I ran across this by chance today from the Snail's Tales blog about snails that estivate in the baking heat on the floor of the Negev Desert in Israel:

The snails avoid reaching the lethal temperature of about 55ºC by withdrawing deep within their shells. This creates an insulating air space between the snail's body and the very hot surface below the shell. The snails are able to withdraw deep into their shells, because they have shells larger than their bodies

Now I have a better understanding of how these creatures survive hot, dry conditions.

[goose]

Very interesting - thanks for that post.

[apple]

coyote said:

Most of the shells have their markings bleached out so much that I felt discouraged trying to identify the species. The lip is light and the columella is dark, like a deep chocolate brown. I wasn't sure if they might be Cepea, because of the stripes. There are a lot of introduced species in this area.


I ran across this by chance today from the Snail's Tales blog about snails that estivate in the baking heat on the floor of the Negev Desert in Israel:

The snails avoid reaching the lethal temperature of about 55ºC by withdrawing deep within their shells. This creates an insulating air space between the snail's body and the very hot surface below the shell. The snails are able to withdraw deep into their shells, because they have shells larger than their bodies

Now I have a better understanding of how these creatures survive hot, dry conditions.

Hi
Thanks for the reply.
Even with their markings bleached I would say that they are Otala lactea, because of the particular shape of the shell and your lip and columella descriptions.
Not sure though, but not only one specie can be on the pictures, maybe also Cepea nemoralis.
I know about those exceptional snails.
Once happened this:
On a certain Natural History Museum, there were exposed Eremina desertorum snails, for about 3 years, and suddenly the shells started to move!! They were aestivating for 3 years and then woke up again!
Eremina desertorum are also desertic snails, they are found from Morocco until Middle East, and they can hang on a lot of heat and drought.
As those interesting Neguev snails, these snails have a quite hard and white shell that reflects more than 95 % of the sun rays.
These are few exceptions, of course, because more than 99% of the snails species can´t tolerate these conditions, not even a bit.
Maybe some specie live in Death Valley or nearby and have some kind of these adaptations?
Here, in Portugal in the desert climate islands of «Selvagens» at 30 degrees north latitude where the sun make a baking heat on the ground and the rain sometime can get years to happen, there are some land snails species that have a white and hard shell as well. Certain similar environments, even when they are distant ( not on this case because these islands are quite near Sahara and Morocco, but in relation to Israel, yes, they are far) make species look similar.
Nice link btw!

[coyote]

Thanks for suggesting they might by Otala lactea. I'll have a closer look the next time Mr Coyote and I go back to that park.

lol at the Eremina snails suddenly starting to move around after 3 years! The museum staff must have been quite surprised!! ;D

[Val]

This is all fascinating, thanks for posting those pics coyote.

Val

[apple]

Hi

LOL. I guess it was in London Natural Museum that they solved to be back... One of them died few months after that, I think, but the other ones are fine. lool.

[donovanbyrd]

i have the ones on the garbage canthey are cepaea nemoralisis and mine do the same thing they clime to the top of my cage and stick there all day tell its night

[apple]

I was recently in Central Portugal, in pinewood habitat with sandy soils, the weather was dry and hot, and I saw lots of snails on the top of the plants like in your picture, Coyote.
They were mainly Theba pisana snails but also other species and showed the same behaviour as there... lool.

[coyote]

Apple, do you know if those species estivate throughout the hot, dry weather, or if they spend just the day up in the plants and wake up at night to crawl around once it cools off?

[apple]

It depends on the humidity level at night.
As that particular place that I visited some days ago, was very close to the sea and faced to the West, at night, the dewpoint happened very early ( this means humidity level above 90 %) at around midnight,even when the temperature during daytime reached 104 farenheit ( 40 celsius), so you could see some snails ( mostly bigger ones) active, but only on the leaves and not on the bark surfaces.
As the snails that I saw aestivating on the trees branches in big numbers were mainly small ones, these weren´t seen active and made a sort of lid to protect them from dehydration.

[Katie]

What about climbing up the sides of my cage? Do they not like the soil i am giving them? baring in mind they burrow themselves alot aswell.

(sorry if this question has allwready been answered)

[helikulo]

I'm replying to this thread quite late, but I have a H aspersa currently hibernating and observing him (Laz) has been interesting. I'm surprised that he wants to hibernate as it's quite warm here in my flat. If I take him down and put him on the substrate he goes back up to the lid of the tank and back into hibernation.
I've got a book ('Les Escargots' by Marasco & Murciano) which says snails usually seek a place under cover but off the ground, maybe to protect them against being spotted by predators and heavy rains/ flooding. They also often like to be on the back of a leafy plant, like a fern which also protects them during heavy rains. This may explain why they feel safer perched just under the lid of the tank.

[coyote]

Helikulo, my aspersas have done the same thing. I suspect they might respond to daylength, in addition to temperature and/or relative humidity, when estivation is triggered.

I suppose if a snail were to estivate on the ground, it is too vulnerable to predators for too long a time, so it makes sense for them to climb up. My aspersas have always liked to climb the walls of their tank, as well as twigs and plants in the tank.

Seeing large clusters of snails bunched together in the tops of trees in local parks is quite a sight. Some of them climb a very long way up. It's impressive.

[whodoesntlovesnails]

i have a gralic snail, and i have never seen him even touch the top of his tank. my other garden snails are always on the top though. any resons why my garlic snail is never on the top but my brown garden snails are?

[coyote]

Garlic snails prefer to crawl on the ground in the fallen leaves. That's why their shells are flat. If they had a round shell like an aspersa it would hinder their movement through the debris.

If you see a garlic snail climbing up something, it's probably sick. It would not be normal behavior.