Broodiness of F1 hybrids, produced by the crosses, White Leghorn _??__??_×Barred Plymouth Rock _??__??_ was examined. The Plymouth Rock hens used were those of non-broody strain which was obtained by prolactin-experiment. All of the 29 hybrid hens obtained from the crosses in which non-broody White Leghorn Cocks were used, were non-broody. The above is perhaps the result of the perfectness of broodiness-elimination in the maternal line. Average days from birth to the laying of first egg in these hybrids, and the average number of eggs laid by them during the 1st year, are as follows:
1. A large bamboo-grove round the Shinhama Duck-netting Pond (Imperial House Hold) at the mouth of River Edo, Gyotoku, Chiba Prefecture, offers roost for many thousands of Grey Starlings, Sturnus cineraceus Temminck, in winter. Evening roosting behabior and the dispersal at dawn to the feeding ground 5-6km. apart, the daytime feeding behavior and its change towards evening to flock on a large tree before leaving at sunset to the roost, are described. The bathing is preferably done in late afternoon. 2. Necessary factors for a feeding ground at paddies with some cultivated area, are: scattered trees to rest on, enough water, big trees or pines (at a private house or a local temple) to gather in the morning and evening, also abundance of food (use of much fertiliger) and least menace by people. 3. They breed scattered at suitable hollow trees within the feeding area. Quarrel was observed between pairs for a hollow and almost 1/4 of the flock seemed to have psychologically returned to non-breeding condition by lack of nesting cite. Before this, the birds which abandon the winter roost increased and they began to overnight at a small bamboo-grove within the feeding area (In another feeding area closer to the winter roost, such spring roost was lacking). 4. The main feeding area studied was north to 6.5km. from the winter roost, and was about 12 square km. within which 800-900 individuals were counted. This area can be sectioned into several subareas different in feeding population, from almost 0 to 3 birds per 100 meter square, by difference of surroundine factors. At 14km, from the winter roost was found a feeding ground of another population. (see next issue for Japanese original) 5. Though often overlooked by some farmers, value of starlings as winter protector of paddies from noxious insects and the larvae and also as eliminators of flies growing from the fertilizer, is to be further studied. 6. Summer to autumnal change of the flock's behavior will be described in the next report.
The crocodilians are not the Japanese animals but formerly they were included in the fauna of our country as the estuarine crocodiles live in Palao Islands, Micronesia which were at that time under Japanese Mandate. I found three examples, old and new, among the literature about the crocodiles which were found drifting in the neighbouring sea of Japan but the reason why they drifted this far is unknown. The first crocodile was caught in 1744 off the coast of Iwojima I., Kagoshima Pref. It was presented to the then Feudal Lord Shimazu, the head of Satsuma clan. This was presumably an estuarine crocodile. The second one was a crocodile caught at Amami-Oshima I., Kagoshima Pref. in February 1800. There exists a color painting of this crocodile made at that time from which I can clearly identify it as an estuarine crocodile. The third one was caught in a fishing net off the Toyama Bay, Toyama Pref. in November 1932. This was perhaps the same species. No live crocodilians were introduced in this country before the Meiji Era. But during the Taishô and Shôwa Era crocodiles, alligators and gavials were brought in one after the other to the zoo of Japan.