A Study of the Behavioural Modification of the House Musk Shrew in the Process of Domestication

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Domestication is the operation by which animals are artificially bred through successive generations after having been freed from the natural selection pressure. Investigations of its effect are concerned with the evolution of behaviour, as they provide us with basic informations on how a behaviour pattern becomes specified while increasing its variation within species. Significance of this approach is greater in the behavioural studies, since evolutionary processes cannot be reproduced with fossil remains.Based on the fact of strain differences obtained with inbred mice (Tsuji & Ebihara,1980; Tsuji et al.,1982), the following hypothesis is proposed: Domesticated animals have been pressed for their adaptation by twofold factors, genetic and environmental. A basic trait of behaviour seen as the strain character is an outcome of these controlling forces. Different strains have specified different patterns, which are originally built-in as the potential modes of wild animals of the specie … More s in coping with their environment. This hypothesis must be tested by breeding wild animals artificially.The house musk shrew (Suncus murinus) is used considering its phylogenetic status. Since 1980 we have domesticated wild animals of this species for our research purpose. The animals were originally captured in Tarama Island, Okinawa, and were transported to our laboratory, where they have been bred by non-sib mating in the closed colony.Two behaviours of the basicly adaptive significance are observed; one is the caravaning and the other is the sexual behaviour. Additionally, activity rhythms are recorded and analyzed.We have so far domesticated wild animals of the Tarama line for three generations and have collected data on the target behaviours mentioned above. Although the effect of domestication has not been elaborated yet, data on the behaviours of the already domesticated animals have been successfully collected by the laboratory observations. Their caravaning and sexual behaviours have been described in detail as well as their activity rhythms.It is our task of immediate necessity to establish reliable breeding procedure, in order that we can accumulate sufficient amount of data on the target behaviours for the early stage of domestication. Less