Birds bias offspring sex ratio in response to livestock grazing

Prior, G.L., Evans, D.M., Redpath, S., Thirgood, S.J. and Monaghan, P. (2011) Birds bias offspring sex ratio in response to livestock grazing. Biology Letters, 7(6), pp. 958-960. (doi: 10.1098/rsbl.2011.0264)

Abstract

Livestock grazing, which has a large influence on habitat structure, is associated with the widespread decline of various bird species across the world, yet there are few experimental studies that investigate how grazing pressure influences avian reproduction. We manipulated grazing pressure using a replicated field experiment, and found that the offspring sex ratio of a common upland passerine, the meadow pipit Anthus pratensis, varied significantly between grazing treatments. The proportion of sons was lowest in the ungrazed and intensively grazed treatments and highest in treatments grazed at low intensity (by sheep, or a mixture of sheep and cattle). This response was not related to maternal body condition. These results demonstrate the sensitivity of avian reproductive biology to variation in local conditions, and support growing evidence that too much grazing, or the complete removal of livestock from upland areas, is detrimental for common breeding birds

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Monaghan, Professor Pat and Prior, Miss Gina
• Authors: Prior, G.L., Evans, D.M., Redpath, S., Thirgood, S.J., and Monaghan, P.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Biology Letters
• ISSN: 1744-9561
• ISSN (Online): 1744-957X