What do declining woodland birds eat? A synthesis of dietary records

Ground-foraging insectivores are prominent among the 26 species considered ‘declining woodland birds’ in southern Australia but the mechanisms driving their declines remain elusive. We synthesised existing dietary records of a subset of the 26 declining woodland birds – 13 ground-foraging insectivorous passerines – to determine the range of arthropods consumed and to estimate the relative importance of each prey group for these birds. Declining insectivores consumed a wide array of arthropods, but diets were characteristically dominated by one or two prey groups: Coleoptera, Formicidae and Lepidoptera accounted for 58% of prey records. Coleoptera contributed the greatest proportion of records (27%) and was the dominant prey group in the diets of nine of the 13 birds. These popular prey groups likely represent core resources supporting populations of declining insectivores and measurement of their abundance may provide meaningful estimates of the availability of prey.

Source:
Razeng, Emma, and Watson, David M. (2012). What do declining woodland birds eat? A synthesis of dietary records. EMU 112, 149–156. http://dx.doi.org/10.1071/MU11099
http://www.publish.csiro.au/paper/MU11099.htm