The latest research from the British Trust for Ornithology (BTO) sheds new light on the benefits for birds of organic farming. Published today in the Royal Society journal, Biology Letters, the results from the latest research suggest that organic farming might not hold all the answers when it comes to reversing the declines shown by some farmland birds.
There is a lot of evidence that shows that natural biodiversity tends to be higher on organic farms than on those that use conventional farming methods. During the winters of 2000/01 and 2002/03, 48 paired organic and conventional farms were surveyed once a month for farmland bird species, to help determine how these birds use the different farms. The results show that whilst the total abundance of most farmland birds was higher on the organic farms during these winters, for birds that feed largely on cereal grain and are partly reliant on winter stubbles this was not the case. It is these species, birds like the Yellowhammer, Corn Bunting and Skylark, that are experiencing the biggest declines.
Dr Dan Chamberlain of the BTO, and lead author of the scientific paper, commented, "Organic farming has clear benefits for a range of species but some aspects of organic farming may not currently provide significant benefits to bird species that are limited by winter seed availability. Once harvesting is completed, it is general practice for farmers on organic farms to plough in the stubbles to prevent an over-winter weed burden, making this resource unavailable to birds." He added, "However, the recent reduction in stubbles on conventional farms, and the phasing-out of set-aside, could result in organic farms becoming more heavily used by some granivorous species — only future monitoring will tell."
A PDF of the full paper is available here (117kB).
This work was funded by Defra and was a joint project between the BTO, CEH Lancaster and the Wildlife Conservation Research Unit, Oxford.