Seasonal Fluctuations in the Numbers of Rufous Turtle Dove Streptopelia orientalis Using Cultivated Fields, in Relation to Feeding Conditions

Abstract

(1)Rufous Turtle Doves Streptopelia orientalis using the cultivated fields and forest aroundthe National Agriculture Research Center, Tsukuba were counted from April to November in 1983 and 1984. The number of doves often increased in plots where wheat, barley and corn had just been harvested. On the other hand, the number of them in forests did not show such marked fluctuation.(2) An analysis of crop contents from seven doves showed that they were almost exclusively vegetarian with the seeds of wheat and barley making up more than 80% of the contents.(3) The materials available to dove's foods were collected from quadrats placed in forest floor and cultivated fields. There was a little vegetable materials in the forest floor, but a large amount of seeds was collected in the plots where crops had just been harvested.(4) These results suggest that doves leave their foraging sites where foods had become scarce and aggregate in the sites with a planty of foods, such as plots where crops had just been harvested.