11 January 2007

Why did the earthworm climb the tree?

wormonbeech1

I saw this earthworm moving horizontally on the wet trunk of a live beech tree last Saturday morning when I was actually looking for slugs. It was about knee high above the ground. A few seconds later, it started crawling down towards the roots.

wormonbeech2

Everything that grows on beech trunks, the fungi and the algae, are rather flat. I don't think an earthworm's mouth anatomy would let it eat any of that stuff, although I could be mistaken. I suspect this individual was simply exploring, taking advantage of the wet trunk to experience life above the ground for a change.

11 comments:

Snail said...

I have some vague recollection of earthworms living in epiphytes in tropical rainforest. Presumably they feed on the decaying leaves caught up by bromeliads and bird's nest ferns. I suppose they get there by climbing ...

But this doesn't explain why an earthworm would go wandering in a temperate beech forest. Perhaps it's doing it for the fame and fortune? The Marco Polo of oligochaetes.

AYDIN ÖRSTAN said...

I see earthworms often on dead trees on the ground, usually under the loose bark. But there is stuff to eat there: leaves & powderized rotten wood that accumulate on the trunks.

I think this one was just checking it out.

Nuthatch said...

We all need a little new perspective now and again.

Marcus said...

I just found a dead tree with plenty of earthworms living in holes within the bark. Will post it later.

Lucas said...

Does anybody know about Annelid worms within temperate forest canopies?
Today I was climbing a Eucalyptus globulus and found small earthworm-like worms about 30-40 feet above ground. They were living under the outer layer of wood/bark on a rotting branch. The tree itself was living and mostly healthy.

AYDIN ÖRSTAN said...

Lucas, that's very interesting. I suppose once the bark starts to get loose, the worms get under it at the ground level and then make their way up all the way to the top.

AYDIN ÖRSTAN said...
This comment has been removed by the author.
ümit said...

I suspect your climber was an introduced Dendrodrilus rubidus (European bark worm) which is indeed only epigeic with some inclination to climb trees.

Lucas, i think your observation may or may not belong to arboreal earthworms. That is arboreal species in your country are small (tick), but rainforest dwellers. They may be caterpillars (leggy) or nematodes, also the species i wrote above.

Lucas said...

Thanks for the input. I didn't know that worms frequented arboreal habitats. What is interesting is that the tree appears to be without rot, but with isolated limbs suffering from white rot. Do the worms crawl thirty feet on healthy bark, or do you think the tree has a deep pocket of rot under the surface? Either way, it is an amazing feat for a 4cm worm!

joy said...

Hi, have you read of this arboreal earthworm? http://journals.cambridge.org/download.php?file=%2F41836_6ACA970953672AB08DADBACEECF74C4E_journals__TRO_TRO22_03_S0266467405003111a.pdf&cover=Y&code=ca17daa2edec709bef0a6e06d5ccf9fa
Would you please let me know if you have any report on such an arboreal earthworm?
Thanks.
Joy

AYDIN ÖRSTAN said...

Thanks for the link (it says the file is not available, actually). I don't work with earthworms & don't know much about them.