The importance of cover at Whitburgh

Good cover crops are important as around a third of grey partridge hens are taken by raptors. © Dave Parish/GWCT

BACKGROUND The GWCT have been working with the team at Whitburgh Farms now for eight years The focus is on increasing grey partridge numbers through habitat management and good predation control. Whitburgh has also provided an excellent means of demonstrating key issues to Scottish environmental policy influencers and makers. 2018 represents our eighth year of collaboration with Mr Salvesen and the Whitburgh Farms team on their grey partridge project. We have been monitoring the progress of efforts to increase grey partridge numbers with the aim of starting a small sustainable shoot of wild birds. Historically, reared grey partridges were released on the farm to sustain the shooting, but this stopped in 2008 when Alastair Salvesen, the owner, decided to focus on wild production. With advice from our senior Scotland advisor, Hugo Straker, three-metre grass margins were installed around most fields alongside the 26 miles of hedges, with around four-metres of cover crop adjacent to it – providing excellent nesting sites alongside year-round escape cover and food supplies. The cover crops are typically in place for one to three years before being replaced, which is done on rotation so that there is always plenty of cover in most fields and likewise, one side of each hedge is cut in alternate years to minimise disturbance.

In addition to the new habitats, Graham Rankine, Whitburgh’s gamekeeper of many years, runs an extensive programme of predator control and stocks hundreds of feeders from October to May. He also manages a relatively small shoot of released pheasants, which provide around half a dozen shoot days annually.

Our monitoring, along with Graham’s detailed spring and autumn counts (see Table 1), shows that grey partridges have done well over recent years but with significant knock-backs. Most notable was the poor survival and productivity during 2012 and to a lesser degree 2013, when extreme cold wet weather during the summer reduced grey partridge numbers – from which they are still recovering. The effect of the poor weather was exacerbated by increased predation rates on the hens during this period; our radio-tracking showed that all our tagged hens that year were killed by raptors. Whitburgh has a high density of raptors, especially buzzards, whose densities peak at around 1.3 territories per square kilometre. On average a third of hens are taken by raptors – making good cover crops particularly important.

Whitburgh is now one of the 10 demonstration sites for the Interreg North Sea Region PARTRIDGE project, an EU-funded venture showing how grey partridge

TABLE 1

Grey partridge densities (per100ha) at Whitburgh Farms

2010 2011 2012 2013 2014 2015 2016 2017 2018

Mr Salvesen (centre right) discussing management at Whitburgh with other PARTRIDGE partners during a site visit in May. © Dave Parish/GWCT

management can improve farmed landscapes for a range of wildlife (see pages 54-55). A key part of this is the introduction of new long-term cover crops that should provide all the resources grey partridge need, all year round. As well as providing additional cover from raptors, this cover may be particularly pertinent at Whitburgh because these crops can provide quality nesting habitat, of importance because badger numbers have increased to the point where they are now probably the most significant nest predators and are preventing the snaring of foxes because of the risk of by-catch. The new PARTRIDGE cover crops offer good nesting cover in large blocks or wide strips making it harder for badgers and other predators to find nests located within them. These were introduced at Whitburgh in 2017 and 2018 and we are watching with interest how partridge numbers respond.

Encouragingly, the number of grey partridges at Whitburgh is now able to sustain a small shoot. In 2017/18, small numbers were shot for the first time, with this continuing in 2018/19. A fair reward for the years of hard work that the farm team have put into managing the site.

KEY FINDINGS Monitoring has highlighted some of the challenges that grey partridges face at Whitburgh, like poor weather and predation. Whitburgh is now one of 10

PARTRIDGE demonstration sites and has introduced new long-term cover crops. Grey partridge numbers can now sustain a modest shoot, one of few in Scotland.

Dave Parish