This is the summary for the breeding biology of the Grey Starling so far reported in Nos. 9 and 10. In the article in No. 10 the data obtained in 1957 are cited when necessary, but the details will be published elsewhere.
The general results are: 1) Commenced from early February, the preparatory period lasted almost a month and half during which the birds acted by pairs staying at nest-site and going out for feeding (within about 800m.). But, the winter flocking was maintained out on the feeding grounds until early April. From March they gradually abandoned the winter roost to sleep at the bamboo thicket of their colony (the spring roost) (but where this is not available the winter roost is maintained). During the egg-laying period, they seemed to roost at each nest-site separately for a short time, but during the incubation and feeding periods one of the pair (possibly the male) or both birds (after chicks are fairy grown) went to the roost, and the fledged young are guided to it by the parents and other adult birds. 2) As shown in the Tables 3, 4 and Figs. 4, 5, it is to be noticed that the first broods are successful by the coincidence of the highest food abundance and availability (of mole-crickets dug out by ploughing) with the chicks' fledging period, but for the second chicks the available foods are mainly small larvae and miscellaneous (Fig. 4) and thus, the parents could not bring enough quantity of food in later broods (cf. Fig. 6 for mal-nutrition of such chicks compared with those of the first brood). This point should be studied in future in the early ploughing districts (and the results of 1957 obtained in different food situation, such as in city zone, will be given in another paper). 3) In the colony, the nest-site territories were noticed (Fig. 7), and the pairs of bad sites or those which failed to get nest-hole spent much time for quarrel or seeking good sites. Such a psychological state prolonged the egg-laying almost 20 days in some cases, and thus, the latest clutches were laid over a month later than the earliest. Good-site nesters were therefore early layers and are possibly old birds, but often suffured competition with others. After flying of the first brood chicks, some nest-boxes were at once utilized by Tree Sparrow (Table 6) and were occasionally reoccupied by the starlings (Table 8a). 4) The nesting for second brood was made after completely taking out wet dirty material of the first brood nest (Table 6.) This was observed on the 2nd and 4th days after leaving of the first brood chicks, and new nests were completed after about 4-8 days, the eggs having been laid on the 5-16th days (Table 8a). 5) Before and during the nesting period there were found some eggs dropped on the ground, crashed on the roof or laid on the bare floor of the nest-boxes, or also under roosting place. This is considered as a case of disorder between the bird's psychological condition and breeding cycle. 6) In the nesting period, the both sexes always act together, and the nest material (chiefly dead bamboo leaves, pine needles and some feathers of domestic fowl) are gathered within the colony, even under nesting trees. 7) Almost all the nest-boxes were quickly occupied by putting in a few material (Gibb's "spurious nest", and may be an expression of the male's nest-owning appetite' (Kortlandt, '55)) which are sometimes taken out or reput, but the nesting advanced very slowly, the period of 24-42 days being roughly divided into three stages as shown in Table 7, and the nest is usually suddenly completed by the 'final stage' in about 4 days. They work hardest in the early morning and only at leisure in the afternoon. Their daily routine is the chain of "stay at nest-site" (nesting or mere inspection and rest) and "off for feeding", the peaks of the latter phase being in the morning and especially in the evening (Table 9 and Fig. 8).