Relative abundance of invertebrate taxa in the nestling diet of three farmland passerine species, Dunnock Prunella modularis, Whitethroat Sylvia communis and Yellowhammer Emberiza citrinella in Leicestershire, England.

Abstract

The level of invertebrate identification in the diet of declining farmland birds could be critical to the understanding of dietary requirements and development of conservation measures. This paper compares results from identification to order and family levels to determine the invertebrate taxa most important for the nestlings of three farmland passerine species. Using faecal samples the invertebrate component was studied in the diet from 23 Dunnock, 36 Whitethroat and 11 Yellowhammer broods on arable farmland in Leicestershire, England during May and June of 1996 and 1997. The same invertebrate taxa were found in the diets of all three species, but significant differences occurred in their relative abundance. The relative abundance of Lepidoptera, Gastropoda and Hemiptera were similar for Whitethroat and Yellowhammer but both species differed significantly from Dunnock. Within each of the orders Hemiptera, Hymenoptera, Diptera and Coleoptera, the relative abundance of the dominant families were also compared between bird species. The relative use of the invertebrate taxa by the three species is compared with other studies. The importance of identifying all taxa, rather than only combined ones, at the level of order is discussed, as it is this fine detail that may be important in determining detailed habitat requirements for invertebrate food groups in conservation management prescriptions.