The influence of crop tiller density on the breeding performance of a cereal-nesting specialist

In the pursuit of maximizing agricultural yields and profits, crop management under intensive agriculture has reduced the heterogeneity of crop sward structure within fields. Several farmland bird specialists that nest within arable crops have undergone marked population declines during recent periods of agricultural intensification. Understanding the mechanisms that link crop sward structure to demographic fitness and population change may be important for developing effective conservation solutions.
We studied whole-season breeding performance of a declining cereal crop specialist, the corn bunting Emberiza calandra, to test the relationships between crop sward structure and both nest site selection and reproductive output within intensively farmed landscapes. Experimental double-drilling of cereal seed was used to manipulate crop sward structure and explain the observed within-field nest distribution.
The density of crop tillers (reproductive cereal stems) was a strong predictor of...