Observations were carried out for some years on wild and captive specimens of Garrulus glandarius rufitergum and for some eighteen months on captive specimens of G. lanceolatus. The call-notes and some of the behaviour patterns are described and compared. Most of the calls are homologous and closely resemble that of the other species. Most of the calls are homologous in function and very similar in sound, but parallel notes with the hawk-alarm of glandarius and the Tscherr! note of lanceolatus have not been heard by from the other species. The lateral display (Imponiergehaben) of both species is similar in form and meaning. It is not, however, often used by the female lanceolatus. The chin display is definite in both form and meaning in lanceolatus, but much less so in glandarius. The wing-quivering submissive or female pre-coitional display is assumed to be common to both species, but it has not been seen used by lanceolatus in its sexual meaning. Courtship-feeding is described. No feeding of the male by the female has been seen in lanceolatus though it takes place commonly with glandurius in the early stages of the breeding cycle. The mobbing reaction to the sight of a jay in the hand is the same in both species. It cannot, however, normally be elicited from tame glandarius that are reacting socially to their owner by his showing them a live jay in his hand. Unlike most passerines glandarius does not pick up ants in its bill when anting. G. lanceolatus-, however, does so. The Blue Magpie (Urocissa erythrorhyncha) ants in the same manner as glandarius. Lanceolatus reacts to most of the call-notes of glandarius. It does not, however, react to the sight of a flying glandarius as do birds of that species, when sexually excited in early Spring.