The Aggressive and Courtship Behaviour of Certain Emberizines

I Head forward threat postures and calls. (a) The head forward postures of the Emberizines studied differ from those of the Carduelines or Parids in the absence of wing raising or vibration. Gosling's Bunting is unusual in also snapping. Nearly all the components of the posture appear to express aggression. (b) Four types of threat calls, used by different species in different proportions, express either fear or aggression. II Soliciting and Copulation. (a) Bunting female soliciting postures difffer only in small details and resemble those of a number of other Emberizines. Soliciting (in particular the components of wing-quivering, and soliciting calls) and nest building, at low intensities, appear to share short term causal factors. The origins of soliciting components are discussed. (b) Copulations, complete and incomplete, are described. The male Corn Bunting gives a copulation call and accompanying posture, both apparently derived from aggressive responses. III Male Wing-quivering and Nest site Displays. The main courtship displays of male Corn and Redheaded Buntings are wing-quivering displays, which include movements of collecting nest material, and nest-site displays which include a characteristic call and nest shaping movements. Similar displays are described in other Emberizines, and the origins of their components are discussed, as is the relation between nest building and sexual responses. Statistical analyses of sequences of Corn Bunting courtship provide some of the evidence used. Finally the sexual behaviour of the Corn Bunting is summarised. IV Male Fluffed and Bill-raised Courtship Displays. (a) These, unlike wing-quivering displays, sometimes end in copulation attempts. The fluffed displays are connected to the wing-quivering displays by an intermediate display of the Redheaded Bunting; those of the Yelowhammer, Ortolan and Lapland Bunting are less exaggerated than that of the Reed Buting. (b) The Yellowhammer and Lapland Bunting also give bill-raised courtship displays, in which the latter often vibrates the wings. Reversed sexual behaviour is discussed, and the sexual behaviour of the Yellowhammer is summarised. V Pair formation and Song, Paired Behaviour, Sexual Chases (a) Male Yellowhammers give low intensity nest building and sexual responses during pair formation, which is a gradual process. Afterwards, the mate is accompanied about and apparently takes the place of flock companions on the territory. Male Corn Buntings sing and give wing-quivering displays to strange females throughout the season; true pair formation does not occur. (b) Song is often accompanied by a tendency to approach a potential mate (probably in order to behave sexually). (c) Sexual chases and fights are discussed. VI Reproductive Fighting. In the Yellowhammer, Reed and Corn Buntings, this, like normal fighting, depends on tendencies to attack and flee. The differences between the two in the Yellowhammer are probably due to the different conflict situations in fighting at a territorial boundary, and in fighting between birds with definite dominance relations. A sexual tendency is expressed in wing-quivering in the Corn Bunting, soliciting in the Reed Bunting, and perhaps in repeated bill-lowering in the Yellowhammer. The occurrence of song, impeded flight and predator responses is discussed. Certain differences between the fighting of the three species can be related to the nature of their breeding habitats. VII Systematic Concluion ns. The Reed and Rock Buntings, the Lapland and Snow Buntings, the Corn and Redheaded Buntings, and the Yellowhammer, Ortolan and Cirl Bunting, appear to form four rather separate groups.