Factors influencing the resolution of agonistic interactions in a winter population of the Blue Tit (Parus caeruleus)

• Main Author: Scott, Graham W.
• Published: University of Edinburgh 1994
• Subjects: 591.5
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.661671

The agonistic behaviour of Blue Tits was studied between October and March in 1989/90, 1990/91 and 1991/92 at Ormiston Hall, East Lothian, Scotland. The distribution of breeding sites and individual identities of the resident population were recorded during the spring and early summer of 1990, 1991 and 1992. Resident birds were sexed behaviourally during the breeding season. Birds were captured, in mist nets or at the nest, for colour ringing (to facilitate individual recognition) and for the collection of a range of biometrics including age, wing length, tarsus length, the distance from the bill tip to the back of the skull, weight, bib colour and the extent of white feathering on the brow. The biometry of the study population was described. These data were used to develop a discriminant function by which birds might be assigned a most probable sex on the basis of biometrics. (This work has been published: Scott, G.W., (1993). Sexing members of a Scottish Blue Tit (Parus caeruleus) population in the hand during the winter months. Ringing and Migration, <I>14</I> pp 124-128.) It was demonstrated that a subset of the winter population developed an affinity for a particular feeding area during their first winter, which was close to that area of the study site which became their breeding territory. The agonistic behaviour of the Blue Tits in the vicinity of an artificial food source was recorded and described. Overt physical fighting was found to be rare in the context of the observed interactions, and it was suggested that one or more other factors might be involved in the resolution of agonistic encounters.