grant burleigh's picture

Large group of slugs (plus woodlice) under a stone.

Observed: 6th January 2013 By: grant burleighgrant burleigh’s reputation in Invertebratesgrant burleigh’s reputation in Invertebratesgrant burleigh’s reputation in Invertebratesgrant burleigh’s reputation in Invertebratesgrant burleigh’s reputation in Invertebrates
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Description:

The mix of slug species* here suggests that this is not a nest involved in reproduction.
“Why so many slugs?” I am wondering. Perhaps the stone just happened to be particularly damp underneath. Or… we have had several days of dry weather here after the previous extensive rainfall. Perhaps members of an expanded population of slugs, having become habituated to wet conditions, actively congregated together to conserve moisture after the weather turned drier.
* I make the tally: 6 Leopard Slugs, three of an Arion sp. and three keeled slugs.

Identifications
  • Slugs
    Confidence: I'm as sure as I can be.
  •  
    Likely ID
    Irish Yellow Slug (Limacus maculatus)
    Confidence: I'm as sure as I can be.
Species interactions

No interactions present.

Comments

grant burleigh's picture

Slugs (cont.)

Thanks very much for that. (My mind has been running to this observation as possible basis for investigations on slug behaviour)

Brian Cambridgeshire's picture

Indoors or out?

Actually, the huddling behaviour was studied quite intensively, by a team led by Dr Tony Cook in Ulster, in the 1980s or 1990s. Theirs was mainly captive studies of behaviour.

As far as I know, it's not been extended to field observations. It's worth noting, Irish Yellow Slugs in particular are individually distinct, the mantle pattern in particular being recognisable. So, you can monitor movement, homing etc., without needing to mark the animals (not easy in slugs!).

Brian