عنوان مقاله [English]
Birds are one of the most diverse groups of ecosystem service providers and exhibit the most diverse range of ecological functions among vertebrates. However there is a little known of their roles in most ecosystems. In this study 49 Eestern rock nuthatch captured from Markazi, Isfahan, Fars and Kermanshah province. The dietary composition of this species was studied by analyzing stomach contents, using a stereo-microscope. The result showed Among the insects feeding, Estern rock nuthatch fed predominantly on beetles (coleopteran (relative frequency: 40.21%., percentage of occurance: 75.51 %., relative volume: 26.92%) and Bugs (Hemiptera(relative frequency: 25%., percentage of occurance: 46.93 %., relative volume: 37.11%).also Among the plants feeding, Eastern rock nuthatch fed predominantly on (Amygdalus scoparia: relative frequency: 64.57%., percentage of occurance: 51.02 %., relative volume: 46.15%) ., (Ficus carica: relative frequency: 10.81%., percentage of occurance: 8.16 %., relative volume: 19.23%) and (Fabacea: relative frequency: 10.81%., percentage of occurance: 8.16 %., relative volume: 3.84%). .in this study result showed among the insect feeding, Eurygaster integriceps that the main pest of wheat and barley in Iran with high relative volume consist most dietary composition of this species.