The true impact on individual bird species must be re-evaluated before the government takes any more decisions on set-aside.
That’s one of several action points advocated by a pair of plant breeders responding to DEFRA’s set-aside consultation, which ended on 27 May.
Retired PBI Cambridge wheat breeder John Bingham (pictured), who farms in Norfolk with stewardship since the 1980s, and RAGT Seeds’ Richard Summers acknowledge that the decline in farmland birds is linked with the modern productive farming needed for food security.
However, they stress, the widely reported DEFRA figure of a 13% fall in the population of 19 species of farmland birds from 1994-2007 masks big variations that have barely been mentioned or discussed.
Their examination of the original data from the Breeding Bird Survey 2007 (the British Trust for Ornithology, the Joint Nature Conservation Committee and the RSPB), paints a very different picture for individual species, most significantly yellowhammers and linnets, which diminished greatly throughout the country (see below).
DEFRA avge all species
Source of DEFRA data: The Breeding Bird Survey of 2007 by BTO, JNCC & RSPB
* Biodiversity Action Plan species
BTO has shown that yellowhammers and linnets are particularly dependent on small seeds over the February-March “hungry gap”.
The breeders acknowledge that the birds may have made use of set-aside in summer. “But considering that their steep decline was associated with compulsory set-aside over the whole 1994-2007 period, there’s no evidence that set-aside was of any significant benefit to them”, they say.
“Their occurrence on set-aside or stubble in February and March didn’t necessarily show they were adequately fed. It could simply be that they had nowhere better to forage and were just dying there – as was the case in the 1950s for woodpigeons before oilseed rape was introduced.”
“The evidence from set-aside in this respect is not that mitigation for set-aside loss is needed, rather it proved that modern stubbles are largely ineffective over the ‘hungry gap’.” If carried on to a second year they can be excellent but impracticable due to grass weeds and take-all in the following first wheat.
The two men suggest the “remarkable” increase in the goldfinch population may be explained by its increasing role as a garden species.
The decrease in skylarks in all areas except Yorkshire has occurred despite set-aside’s nesting opportunities, but the woodpigeon’s pest status can make it hard to cater for other species at risk.
They advocate more thorough co-ordination of existing experimental evidence to produce a management manual.
Bridging the “hungry gap” is particularly difficult, other than via very large areas of deliberately weedy stubbles and sown seeds – in effect farmland bird reserves.
They believe more could be made of game cover to provide plenty of small seed until the year’s end, but stress that the choice of seed-holding species to follow is very limited. “Fodder radish is outstanding and triticale good,” says Mr Bingham.
They suggest research at the John Innes Centre to develop shatter-resistant oilseed rape could help, as could breeding new perennials based perhaps on wild cabbage.
Practical advice on establishing and managing arable wild flower/grass mixtures is essential, especially when converting long established but now outmoded stewardship grass margins, which probably need glyphosate treatment, they say.
Long-term management is critical to avoid the influx of undesirable weeds like creeping thistle and docks, explains Dr Summers.
Mr Bingham says it’s worth noting that modern high-yielding crops release land for stewardship and new nature reserves, such as the planned 3700ha Cambridgeshire Great Fen, which benefit non-farmland birds.
“Without highly productive farming we would still have farmland birds of the 1960s but would be looking for the next loaf of bread.”
The breeders’ comments come hard on the heels of first results from the £1m Sustainable Arable LINK Farm4bio project.