Will grass snakes hibernate in compost heaps?

[daveO]

Last year I built a compost heap in my garden, just 4 slatted sides made of pallets. I generally add green material, cover with cardboard and add another layer then stir together at a later date.

I was told to keep turning the heap regularly to get air in there but the first time I went to do it there was a slow worm in there under a layer of card so I left it alone. The next time there was a large grass snake so again I left it and the time after I found a clutch of eggs so no go again. I checked at the start of september and the young snakes were still in there but does this mean they'll stay there all winter? It's not the end of the world if I can't turn it and I'll start a new heap this year I suppose.

 

[Arjati]

They probably will I'm afraid - I'd love to have grass snakes and slow worms in ours mind

 

[Elen Sentier]

Yes they do. We usually have them. If you use something like QR or Mausdorfer compost prep you don't need to turn again until spring. Can give more details if you want. My uncle taught me this back in the 1950s, been doing it successfully ever since

I forgot to say get your QR here



behind every creative woman there's usually a very talented cat ...

 

[decorum]

For best practice and how to help them as best you can it'd be a good idea to drop JonathanD a line ~ PM him through this forum.

 

[JonathanD]

For best practice and how to help them as best you can it'd be a good idea to drop JonathanD a line ~ PM him through this forum.

Too late. I'm already here

As a general rule, grass snakes don't like hibernating in compost heaps unless they are well sheltered from the wind and protected from at least three sides. Reptiles like very stable temperatures that don't vary at all during the winter months, so that means going underground. But there is a chance that your compost heap my be stable, so turning it now is possibly not a good idea.

DEFINITELY DON'T turn it during Spring though. This is when the snakes are mating and laying eggs and possibly the worst time to disturb the site. The best time to turn is late September/early October after all eggs have hatched. This will then create airspace within the heap without established surface tunnels, and so make it a better option for hibernating. The heap will also be in the best condition for incubating eggs the following year.

 

[Toddy]

How do mice and grass snakes interact JD ? Mind the only grass snakes I've seen were pencil thick and I don't think they'd manage an adult mouse
Every compost heap I've had has been full of brandling worms, and there are always mice that set up home in them.
I think on balance I'd rather have the grass snakes, tbh especially since I don't have a cat anymore.

cheers,
M

 

[JonathanD]

Grass snakes will take young mice from the nest. But as they don't have a venom that will kill a mouse virtually instantly like our adder, or possess the ability to constrict and kill their prey before eating like the smooth snake, it makes eating a live mouse dangerous and almost impossible without sustaining injury. Grass snakes tend to stick to slow moving, non threatening animals like frogs, toads, newts and fish. Far easier to eat these live, and they slip down nice and easy too.

Still, like I said, they will readily take rodents from the nest, so are a great help that way. They'll also single out diseased and weaker amphibians which benefits a ponds ecology. Interestingly, they will take frogs that are succumbing to this new virulent disease that is killing them off in the UK and may be one of the factors to halting the spread of this disease and slowing it to a manageable level.

 

[Mesquite]

Grass snakes will take young mice from the nest. But as they don't have a venom that will kill a mouse virtually instantly like our adder, or possess the ability to constrict and kill their prey before eating like the smooth snake, it makes eating a live mouse dangerous and almost impossible without sustaining injury. Grass snakes tend to stick to slow moving, non threatening animals like frogs, toads, newts and fish. Far easier to eat these live, and they slip down nice and easy too.

Well you live and learn something new every day.

I'd always assumed that if a snake was non venomous it would naturally constrict its prey to kill it

 

[JonathanD]

I'd always assumed that if a snake was non venomous it would naturally constrict its prey to kill it

You'll find that most small colubrids that live near or around water aren't constrictors. It might also surprise you to know that grass snakes are mildly venomous, like almost all colubrids. Their venom has zero to very little effect on humans (grass snakes being in the zero category). It's not understood to what degree this mild toxin affects their prey yet, but we are trying to find out. Bear with me

 

[Toddy]

Thank you JD

M

 

[JonathanD]

Thank you JD

M

'Tis a pleasure Mary.

 

[blacktimberwolf]

Arn't snakes that hibernate in compost heaps more liable to being disturbed or even eaten by such things as rats, cats, badgers or foxes for example.

I found a six inch portion of a Western whip snake last winter....carefully placed on top of a grass tuft, fresh enough to eat..............that was one snake that didn't choose a good place to hibernate

 

[JonathanD]

Arn't snakes that hibernate in compost heaps more liable to being disturbed or even eaten by such things as rats, cats, badgers or foxes for example.

Absolutely. That's another excellent reason you don't generally get them hibernating in them.

 

[RICKY RASPER]

Being from Ireland I wouldn't really know, but don't compost heaps get very very hot? What sort of temperatures do grass snakes tolerate?

 

[JonathanD]

Being from Ireland I wouldn't really know, but don't compost heaps get very very hot? What sort of temperatures do grass snakes tolerate?

Yeah, that's why they are unsuitable for hibernaculum sites during winter as the internal temperature is not a constant. But they are perfect for egg incubation.

 

[Toddy]

Not all heaps get hot.
Worm worked ones don't get hot enough to kill weed seeds, but if the worms are the right ones the compost is beautiful stuff the maker just needs to be a bit careful of what they're fed.....like anything but stuff that will sprout.
The outer layers of the heap certainly freeze when the temperature falls, and since the bins are black plastic and heat up in the Sun, the temperature really fluctuates.
That's what made me wonder about how good mine would be for snakes
Oh well.

M

 

[RICKY RASPER]

Yeah, that's why they are unsuitable for hibernaculum sites during winter as the internal temperature is not a constant. But they are perfect for egg incubation.

Does the incubation temp have an effect on the sex of the brood?

 

[Elen Sentier]

Not all heaps get hot.
Worm worked ones don't get hot enough to kill weed seeds, but if the worms are the right ones the compost is beautiful stuff the maker just needs to be a bit careful of what they're fed.....like anything but stuff that will sprout.
The outer layers of the heap certainly freeze when the temperature falls, and since the bins are black plastic and heat up in the Sun, the temperature really fluctuates.
That's what made me wonder about how good mine would be for snakes
Oh well.

M

Very true Mary, they get called "cold" but are usually warm. Hot heaps will kill weed seeds. Ours are not usually "hot" over winter. We keep our wormeries in the shed and/or scullery where they doesn't freeze. We also find slow worms and grass snakes (never smooth here in Hereford) in our outdoors heaps over the winter. Never found adders in them. We don't turn our heaps very often and never if we find snakes in them but do use the QR and/or preps so the compost is excellent without and it doesn't harm the snakes ... or the worms.

 

[JonathanD]

Does the incubation temp have an effect on the sex of the brood?

Yes, it has a direct effect on the sex.

We also find slow worms and grass snakes (never smooth here in Hereford) in our outdoors heaps over the winter. Never found adders in them.

It's very very rare to find adders on, in or near compost heaps. It isn't the right environment for them.

 

[daveO]

Too late. I'm already here

As a general rule, grass snakes don't like hibernating in compost heaps unless they are well sheltered from the wind and protected from at least three sides. Reptiles like very stable temperatures that don't vary at all during the winter months, so that means going underground. But there is a chance that your compost heap my be stable, so turning it now is possibly not a good idea.

DEFINITELY DON'T turn it during Spring though. This is when the snakes are mating and laying eggs and possibly the worst time to disturb the site. The best time to turn is late September/early October after all eggs have hatched. This will then create airspace within the heap without established surface tunnels, and so make it a better option for hibernating. The heap will also be in the best condition for incubating eggs the following year.

I've been snowed in at home all week with no interweb so I've only just read all this. Great replies though, thanks.

I think I'll just have to let the heap take care of itself. I found the eggs mid August and the young snakes were still in there in October so I guess there is going to be no good time to do this. Not the end of the world I suppose.

The surrounding garden is a maze of mice holes so hopefully they're all underground in this weather anyway. I covered the heap with loads of leaves and thick sheets of cardboard before winter though so it doesn't get too wet and cold though.

I'm trying to keep the area wildlife friendly so hopefully they'll stick around. I've seen loads of small frogs and toads about and I'm making log piles and stuff for them.

Here's a pic of one of the young grass snakes anyway: