Dietary shift of White-cheeked Starlings Spodiopsar cineraceus living in Korean village groves around rice paddy fields

Abstract

We investigated the feeding preferences of the White-cheeked Starling Spodiopsar cineraceus in Korean village groves during the breeding season by means of a fecal dietary analysis using a non-invasive molecular approach. A total of 529 fecal samples were collected from four different study sites, 113 of them (21.4% of all fecal samples) were identified as those of S. cineraceus. Analysis showed that the starling’s diet mostly consisted of animal matter (64.5%), but also contained vegetable matter (32.7%). Terrestrial prey, such as insects and spiders, constituted the largest proportion (65.2%) of species in the diet, although aquatic organisms (26.1%) were also important. Most of the seeds detected in feces were of mulberries, with detection rates rising to 68.1% by the end of May and remaining high until mid-June. Our results suggest that higher water levels in paddy fields due to irrigation could potentially act as an impediment to bird feeding, particularly for small birds such as S. cineraceus and induce a dietary shift to terrestrial organisms from aquatic organisms. In addition, we suggest that human agricultural activities may influence the feeding activities of small bird species such as S. cineraceus in an agricultural ecosystem.