In January 1998, the Ministry of Agriculture, Fisheries and Food (MAFF) launched Arable Stewardship in two pilot areas in England, with considerable success. An aim of Arable Stewardship is to contribute to the achievement of Biodiversity Action Plan (BAP) targets, by offering arable farmers a range of management options that are designed to create suitable habitat or conditions for plant and animal species that have declined or are threatened on arable farmland. Entry to the pilot scheme closed in 2000, but a number of the options have been incorporated into the Countryside Stewardship scheme for 2002.
The aim of the pilot is to test the arable measures under a range of arable farming systems and conditions. The East Anglian pilot area is dominated by cereal farming on heavy soils, but includes lighter chalk soils. The West Midland area has a range of soil types and cropping, and a significant amount of mixed farming. In 1998-2000, MAFF commissioned an ecological evaluation to determine the influence of the options on the creation of wildlife habitats and abundance of threatened or scarce wildlife species. In particular, the Grey Partridge and the Brown Hare, two BAP species, were monitored as part of this evaluation by The Game Conservancy Trust, their nominated lead partner. No significant differences appeared between agreement farms and control farms in the autumn density and productivity of Grey Partridges, or in the winter density of Brown Hares, even though several of the prescriptions had been field-tested for them in the past. The short period of the study was thought to be the most likely reason for the lack in response.
Now, two years later, the options will have matured and the expected benefits should be apparent. Moreover, since 2001 a new Public Service Agreement (PSA) covers the Department for Environment, Food and Rural Affairs (DEFRA), which took over all MAFF responsibilities as well as the environment, rural development, countryside, wildlife and sustainable development responsibilities of the former Department of Environment, Transport and the Regions. One of DEFRA’s PSA targets is to reverse the long-term decline in number of farmland birds, of which the Grey Partridge is one of the most seriously affected. It is therefore important to assess whether Arable Stewardship is capable of delivering more Grey Partridges and Brown Hares, in order for the government to meet both its BAP and its PSA targets.
1. Assess the medium-term impact of Arable Stewardship on the abundance and productivity of the Grey Partridge (BAP/PSA species)
2. Assess the medium-term impact of Arable Stewardship on the abundance of the Brown Hare (BAP species)
3. In light of (1) and (2), provide recommendations to government that will help it meet its BAP and PSA targets
Approach and research plan
Study design and sites
The study design is inherited from the 1998-2000 evaluation of the Arable Stewardship pilot scheme. In East Anglia, Grey Partridges were counted on 21 agreement and 19 control farms, and Brown Hares on 21 and 18 respectively. In the West Midlands, Grey Partridges were counted on 18 agreement and 22 control farms, Brown Hares on 21 and 20 respectively. We will contact each of the farmers formerly involved, with a view to revisiting each farm and repeating the counts carried out in autumn 1998 and 2000 for Grey Partridge, and in winter 1998/1999 and 1999/2000 for Brown Hare. Because of the year-to-year fluctuations in density and productivity that these two species experience (due primarily to weather effects), it is important that agreement and control farms be counted within the same season, so as to measure the true effect of Arable Stewardship and not a composite one biased by annual variation.
Grey Partridge counts
Grey Partridges are best counted directly after harvest, when cover is much reduced and the birds can be seen above the stubble. At this time of year (mid-August to mid-September) the birds are usually in family groups (coveys). Using binoculars, it is possible to distinguish young from old birds, and adult males from adult females, by their plumage. The separation of sexes and ages allows an assessment of both productivity and breeding density from these counts.
Each farm will be counted during either a single morning or evening visit, 2-3 hours after daybreak in the mornings, and 2-3 hours before dark in the evenings. Counting proceeds by driving a 4-wheel-drive vehicle around the edge of each harvested field. Where ground out to the centre of the field is clearly visible, a simple drive round the field is sufficient to count the field. Where visibility is not good the vehicle is driven up and down the field until it is completely covered. Details of all partridges seen are recorded on field maps. For farms of less than 200 ha, every cereal field stubble on each farm will be counted. Where fields contain livestock, these will not be disturbed but scanned with binoculars from the outside. Ploughed fields will also be scanned from the outside. For farms with more than 200 ha, as much as possible will be counted within the time available.
Brown Hare counts
Brown Hares are best counted at night, when they are active, and during the winter, when crops are short and hares can be seen. Hare counts are carried out using a 4 wheel-drive vehicle, handheld spotlight and 7x50 binoculars. Timing is not critical and more than one farm can be visited per night. Counting is done under most weather conditions, but nights with driving rain, fog or which are very cold should be avoided.
Farm maps drawn up during the 1998-2000 evaluation indicate the best viewing points for counting hares on each field. The visible area from each of these viewing points is mapped so that the effective area sampled can be determined. At each viewing point the area is scanned slowly with binoculars and spotlight, sweeping across in one direction and then back again. Hares show up mainly by their eye-shine, but also by their outline and colour. Hare sightings are recorded on field maps along with notes on the state of each crop and other factors that may affect visibility.
Each control farmer will be asked whether he manages any land sympathetically for wildlife, e.g. using beetle banks, conservation headlands, other Countryside Stewardship options or Wild Bird Cover set-aside. Likewise, each agreement farmer will be asked if if he has any non-arable Countryside Stewardship options or Wild Bird Cover set-aside. All farmers (control and agreement) will be asked whether the land is keepered, whether gamebird releasing takes place, and whether Grey Partridges and Brown Hares are shot. These data will provide some capability for investigating the reasons behind unexpected results, should they occur.
The hypothesis to be tested for both species is whether management under AS agreement improves the conservation status of Grey Partridge and Brown Hare. This is equivalent to asking whether, relative to the situation in 1998, when Arable Stewardship was just starting, the conservation status in 2002 is better on agreement than on non-agreement farms.
For Grey Partridge, the variables of interest are the total density of birds recorded on each farm, their young-to-old ratio and the average number of chicks per observed brood ("mean brood size"). For Brown Hare, the variable of interest is the density of animals recorded on each farm. These variables will be analysed using generalised linear modelling. In testing for the effect of Arable Stewardship (agreement v. non-agreement farms) on these variables, the analysis will need to take into account variation between pilot areas (West Midlands vs. East Anglia), variation between years (1998 v. 2002) and variation between individual farms.
The output will be a report that brings together and evaluates the results from this study. The report will include recommendations relating to the operation of the scheme in terms of its ability to deliver the BAP and PSA targets for Grey Partridge and Brown Hare.
An interim report will be submitted for comment by DEFRA by 31 March 2003. Allowing 4 weeks for comments, the report will be finalised by 31 May 2003.