Lawrence, Alistair Burnett

2019-02-15T14:33:03Z

2019-02-15T14:33:03Z

1985

This thesis describes the social organization of a home range group of Scottish Blackface sheep occupying an area known as the Howlet in the Pentland Hills, Midlothian, Scotland. Evidence to support the contention that these sheep constitute a home range group is presented. The home range occupied by the group was found to be at a minimum in winter (the winter range) and at a maximum in summer (the summer range). Using cluster analysis on individuals' location data it was shown that in autumn and winter there was little individual variation in home range behaviour in comparison to summer. Variability in home range size showed a similar trend. Ewes in summer could occupy home ranges differing by as much as 40 ha. It was further illustrated that in winter ewes showed increased gregariousness, forming large sub -groups and being readily influenced by the movements of other sheep, whilst in summer the converse was true. It was concluded that these seasonal variations in social organization occurred largely in response to ecological changes; in winter a reduction in the variability in the quality of the hill swards and the worsening weather; in summer the increase in the dispersion of resources through the growth of the widley distributed Agrostis-Festuca swards. The presence of a lamb in summer would seem to satisfy the ewe's proximal motivation to group, thus allowing her greater flexibilty of movement between Agrostis-Festuca swards.

In contrast to the findings of previous workers, the ewe-daughter bond was found to be of little significance beyond 7 to 8 months. Around this age ewe-lambs formed peer groups that during their first winter moved independently of other group members. In their second summer ewe-lambs became integrated into the larger social group. Early experience was found to be important in determining summer home range patterns of individual ewe-lambs. The cohesion of the home range group seemed to result from the animals' preference for an area and their motivation to form sub-groups; specific bonds between individuals were not of importance in this respect.

Social organization was shown to negate supposed advantages of feedblocks, fed as a supplement to the group during winter. Ewe -lambs did not follow older ewes to the feedblock; 2 and 3 year old ewes did not compete successfully with older ewes when feeding at the block; further the feedblocks apparently decreased the size of ewes home ranges, which it seems must have led to the overuse of the lower parts, and conversely underuse of upper parts of the range.

The results are discussed in relation to literature on wild, feral and domestic sheep. It is concluded that whilst in general terms the social behaviour of domestic sheep remains close in form to that found in feral and wild populations, that there remain unresolved questions over the function of aspects of social behaviour in domestic ungulates. It is argued that that a better understanding of the effects of domestication on, for example, anti -predator behaviour in domestic sheep would help in the construction of a theoretical framework for the study of the ethology of farm animals.

http://hdl.handle.net/1842/34947

The University of Edinburgh

Annexe Thesis Digitisation Project 2019 Block 22

The social organization of Scottish Blackface sheep

Thesis or Dissertation

Doctoral

PhD Doctor of Philosophy