Geoscience Reference
In-Depth Information
worm, its distant, marine cousin found on muddy coasts). This species can reach a
length of 30 cm and a weight of 10 g (
Fig. 34
), making it much the largest soil animal
in this country apart from the mole. It makes permanent burrows that may go down
as much as three metres, but it feeds at the soil surface so, in this respect, it belongs
with the group of surface-living worms. On mild, damp nights it can be seen stretched
out on the ground sweeping a circular area in search of food items. Its tail remains
hooked into its burrow where it is expanded into a diamond shaped anchor to ensure
swift retreat if necessary. The light of a torch, or the vibration of a footstep, is enough
to trigger off the contraction of its longitudinal muscles, and its instant disappearance.
Worms are highly nutritious, and
L. terrestris
is much sought after by badgers, foxes
and owls at night as well as by thrushes, rooks, lapwings and seagulls by day.
F
IG. 35
Aggregation of stones by the lob worm
Lumbricus terrestris
on a quarry floor. Notice the seedlings of
small toadflax
Chaenorhinum minus
among the stones and the surrounding area swept bare by the earth-
worm. (Photograph B.N.K.D.)
All sorts of materials are seized and dragged into its burrow, including feathers
and bits of cloth or plastic; a somewhat mindless activity, seemingly, but almost any-
thing gathered into its midden in its original woodland habitat would eventually be-
come edible. Experiments by J.E.Satchell have shown that
Lumbricus terrestris
actu-
ally has quite a good sense of taste for it shows clear preferences for leaves that are
