Winter game crop plots for gamebirds retain hedgerow breeding songbirds in an improved grassland landscape

The cause of recent population declines in some farmland / hedgerow breeding bird species in the UK is related to a lack of cover and food resources in winter.  In improved grassland areas some of those declines have been particularly acute and some have been shown to be related to the availability of grass and weed seed in winter.  The provision of seed-bearing crops as part of AES options has been shown to benefit some of these birds.  Game crop plots sown on shooting estates for holding and driving gamebirds in autumn and winter have been shown to hold relatively high densities of farmland and wood-edge birds during the winter.
We studied breeding songbirds in hedges in a primarily improved grassland area in the SW of England where there are some large shooting estates that sow relatively large game crop plots (1 - 5 ha) in the landscape.  In this study we found that otherwise similar hedges in terms of size and density near to those winter game crop plots, had between 1.5 and 2 time..., This dataset was collected on Exmoor by two researchers. They undertook bird surveys along hedges at differing distances from wild bird cover plots. The data is the number of birds recorded on each survey and measurements of the hedges such as height, density and width etc. 
The data is a csv file and analysis has been performed in R. , , # Winter game crop plots for gamebirds retain hedgerow breeding songbirds in an improved grassland landscape

Authors:
Rufus Sage (lead author), Maureen Woodburn, Sam McCready, Jenny Coomes (processed the data and did the analysis).

Sage, Rufus; Woodburn, Maureen; McCready, Sam; Coomes, Jenny (2023), Winter game crop plots for gamebirds retain hedgerow breeding songbirds in an improved grassland landscape, Dryad, Dataset,

Files uploaded:

* R code for analysis: Exmoor data - for upload.R
* CSV of data: exmoordatafull.csv

The dataset contains information about the hedges and game cover, as well as the number of birds seen per survey.

Column headings in dataset:

ID: unique to all rows

site: 1, 2 or 3

site.new: categorical version of site (a, b or c)

transect.orig: the original transect number

transect.code: unique transect number for each different cover plot, with five hedges within it.

distance: five bands: 1 to 5. (changed to categorical in the code). 0-50m, 75-150m, 200...