Friday 6 November 2015

A tale of two farms, and two approaches to bird conservation

We have combined forces, and data, with RSPB colleagues to examine the changes in bird numbers on our respective farms, our own farm at Loddington, and the RSPB’s ‘Hope farm’ in Cambridgeshire.  The results have just been published online in Bird Study.

As a result of the management on the two farms, since 1992 at Loddington, and since 2000 at Hope Farm, songbird numbers have increased substantially compared to the regional trend.  Farmland birds, including BAP species, have done particularly well at Hope Farm, whereas along with some farmland and generalist species, BAP species associated with woodland such as Spotted Flycatcher, Song Thrush and Bullfinch increased more at Loddington.  The targeted management at both farms delivered annual rates of increase of 10-20% for a wide range of species. 
In contrast to the more open farmland landscape at Hope Farm, the wooded farmland at Loddington has also supported higher predator numbers.  Crows and magpies were controlled at Loddington during the early part of the study period, but as a research exercise to understand the relevance of this to bird conservation, predator control was not carried out during the latter part of the period.  There was an associated decline in numbers of some songbird species towards the end of the period, especially species with open, cup-shaped nests that are vulnerable to predation.  This predation effect may explain the tendency for higher annual rates of increase in bird numbers at Loddington than at Hope Farm.
There were also significant benefits arising from the creation and management of habitat on farmland, especially at Hope Farm. Habitats designed to provide insect food for birds during the breeding season had particularly strong positive effects on a range of species.  Such habitats include conservation headlands, pollen and nectar mixtures, floristic margins, beetle banks, skylark plots and ponds, all of which can contribute to the abundance of potential insect food, and access to them by foraging birds.
Landscape characteristics may influence the response of bird populations to the creation of new habitats
Comparing two farms with different landscapes and different approaches to bird conservation has taken us a step forward in our understanding of how to restore bird numbers.  It is clear that we need to recognise differences across the lowland landscape and accept that a blanket approach to all farms is not appropriate.  Bird conservation on farmland needs to accommodate variation in landscape type, and importantly, the interests of the farmers responsible for managing it.
Underlying this though, is a clear need for a mechanism to support farmers to create habitats that are based on sound science, compatible with farm business objectives, and practical to create and manage.  Applicants to the new Countryside Stewardship scheme will soon discover whether their applications have been successful.  For those that are, we have demonstrated that Stewardship provides an essential tool in the box for restoring bird numbers.

The Bird Study paper is available at http://www.tandfonline.com/doi/full/10.1080/00063657.2015.1090391