Dynamic study of the burrowing behaviour of Aporrectodea nocturna and Allolobophora chlorotica: interactions between earthworms and spatial avoidanceof burrows
Y. Capowiez et L. Belzunces, Dynamic study of the burrowing behaviour of Aporrectodea nocturna and Allolobophora chlorotica: interactions between earthworms and spatial avoidanceof burrows, BIOL FERT S, 33(4), 2001, pp. 310-316
The behaviour of earthworms belonging to two different species and ecologic
al types (Aporrectodea nocturna and Allolobophora chlorotica) was studied u
sing two-dimensional (2D) terraria. Two experiments were set up to gain ins
ight into the nature of interactions between these earthworms. Firstly, the
evolution of the burrow systems was analysed with the density of the earth
worms varying from one to five individuals. Secondly, a burrow system was f
irst established by using one earthworm which was then. removed before the
introduction of a second earthworm. This second earthworm therefore encount
ered a burrow system created either by a conspecific earthworm or by an ear
thworm of the other species. These experiments showed that: (1) intra- and
interspecific interactions occur between earthworms, (2) these: interaction
s are dependent on the physical presence of the earthworms, and (3) spatial
avoidance can occur (A. chlorotica avoiding burrows created by A. nocturna
). The results suggest that earthworm burrow systems art: "'individual stru
ctures", rarely used by other earthworms when inhabited. When abandoned, th
e burrows may be recolonised depending on the ecological type of the earthw
orm under consideration.