BRANTA — Teddy A. Wilkin
Summer habitat preferences of female Corn Buntings
Institution: University of Aberdeen, UK
Supervisors: I Patterson
Details: MSc 2003 (Completed)
Current Address: Dept of Zoology, South PArks Road, University of Oxford, Oxford (Jan 2006) Email
Subject Keywords: GIS, Compositional analysis
Species Keywords: Corn Bunting Emberiza calandra
Abstract
There is an increasing body of evidence to suggest that, in Great Britain and across much of Europe, many species of farmland bird are suffering dramatic declines in abundance and considerable range contractions. These declines are strongly and consistently correlated with a suite of concurrent changes in agricultural practices, mostly related to increased productivity. In Great Britain, the Corn Bunting (Miliaria calandra) has declined in abundance by 80% between 1973 and 1994, and in range by 32% between 1972 and 1991. This study, in cooperation with the RSPB, investigated the summer habitat preferences of breeding female Corn Buntings in northeast Scotland.
The duration of provisioning foraging trips did not differ between females. Foraging trips made during the middle of the day were longer than at other times of the day. The duration of foraging trips differed between habitats visited; the shortest trips were made to grass margins, followed by winter barley. The habitats surrounding nests sites differed significantly from random. However, it was thought that observing from a car introduced a sampling bias towards the amalgam habitat category other, which included tracks and roads, plus Corn Buntings that bred more than 200m from tracks or roads were not included in the analysis. Grass margins were consistently an important habitat surrounding Corn Bunting nests.
Grass margins were the most preferred provisioning habitat with respect to availability, followed by winter barley and set-aside. Spring barley, oats and pasture were preferred less than was expected from their availability.
Corn Buntings have insectivorous chicks. Therefore, an attempt was made to link invertebrate abundance with foraging habitat preferences. Foraging habitats (grass margins, winter barley and set-aside) had a significantly higher abundance of chick food invertebrates than non-foraging habitats (oats and spring barley).
This study confirms the importance of grass margins to breeding Corn Buntings and recommends that further habitat preference studies employ sufficiently high resolution mapping techniques to further investigate this preference.