By Derek Gruar, Senior Researcher, Hope Farm
One of the core tasks here at Hope Farm is monitoring the numbers of birds that are actually using the farm. In summer this requires walking the farm boundaries and recording birds that are seen and heard onto maps. Compared to winter this is straight-forward as from spring-time onwards, birds are starting to hold territory and males readily sing to announce that this part of the field or hedgerow is theirs. Repeated visits over the summer allow maps to be plotted for each species and it soon becomes apparent that that individual birds are found in the same place on subsequent visits, the birds territory.
However in winter, most birds have no territorial hold on a discrete area and are free to roam where they like, the main driver of all this is of course food. Put food out in your garden and birds will soon take advantage of your generosity.
On the farm to determine bird numbers over the winter we conduct monthly whole farm counts where the farm is divided into small sections and is surveyed simultaneously by a small number of hardy volunteers that brave the weather and the mud! All birds seen using the farm are recorded on maps and after a thorough review to make sure that we don’t count the same flock of yellowhammers, or covey of grey partridges, twice; we calculate a figure for the numbers of birds seen on that particular day.
For example, in 2001 on the first ever January count 534 birds of 30 different species were recorded as using the farm. Woodpigeon was the commonest, contributing 216 of these birds. Of the farmland birds of conservation concern this count included 15 skylarks, only a single each of yellowhammer and reed bunting and no linnets or grey partridges. Common birds found included 50 blackbirds, 27 blue tits, 18 dunnocks and 16 robins.
In 2011 during one of the harshest winters in recent times, the farm attracted 1338 birds of 39 different species. Woodpigeon was again the commonest contributing 307 of these birds. Of the farmland birds of conservation concern this count included 113 skylarks, 157 yellowhammer and 49 reed bunting, 12 linnets and 31 grey partridges. Common birds found included 58 blackbirds, 57 blue tits, 14 dunnocks and 25 robins. These have shown some small increases but nothing in the scale of the increases of the birds that are dependent on farmland. We attribute these increases to the presence of winter bird food on the farm as in winter 2010/11 we had several small (0.5ha) areas of wild bird cover, unharvested crop strips (both winter wheat and oilseed rape) and 1ha enhanced fallow (EF22 Plot) all of these producing seed resources for farmland bird species.
After the harsh winter came the drought, and the associated problems with crop growth and establishment particularly of bird cover crops. For winter 2011/12 this has meant that we have a massive reduction in the area of winter bird food available with just one small wild bird cover plot and 0.5ha of unharvested winter wheat. With this lack of food the January 2012 count was lower than previous years with 1016 birds of 39 species, Woodpigeons the commonest bird with 178 recorded. 118 skylarks and 35 grey partridges were exceptional counts and only 16 yellowhammer and 3 linnets illustrated the lack of food available for these species currently on the farm. It’s interesting to see diversity has increased over time, but it is compelling evidence that winter food availability is a considerable factor in attracting birds onto farmland in winter.
Photos: Andy Hay (rspb-images.com)