This month we’re shining the spotlight on one of our rarest, most secretive birds - the corncrake. In the first blog, we introduced these birds and outlined how they came to be largely confined to north and west Scotland. Chris Bailey, RSPB Scotland's advisory manager, now picks up the story about how science was used to identify the key issues affecting the species leading to the creation of management schemes to help corncrakes, and the role of our policy team lobbying government for sufficient funding to support these schemes.

Bringing corncrakes back from the brink

The national survey in 1993 showed that corncrakes, once widespread across the UK, had increasingly become confined to the islands of Scotland. Numbers had declined by a third from the first survey in 1978. As a result, in the late 1980s, the RSPB had started intensive studies into corncrakes with the aim of identifying measures that would reverse the declines in their numbers.  These studies, which involved ringing and retrapping, radio tracking birds and field observations (no easy given how elusive these birds are!), helped us gain a better understanding of these secretive birds and identify some of the critical drivers for their decline.

Our research showed mowing to be one of the key factors. Corncrakes like to make their nests in the dense vegetation of fields. However, as the mowing season overlapped substantially with corncrakes’ breeding season many nests were being destroyed and chicks killed.  Another factor was a lack of tall ungrazed areas in early spring. Corncrakes rely on these areas when they first return from Africa for protection and food until the grass in the hay and silage fields has grown tall enough for them.  

Understanding this meant that the RSPB to could develop the following conservation measures to help corncrakes:

1)      Increasing the amount of tall vegetation in early spring and late summer. These cover plots were increased by fencing off certain areas to protect existing tall vegetation or by creating new areas.

2)      Reducing the overlap between corncrake breeding and mowing seasons by paying crofters to delay mowing until 1st August or later.

3)      Reducing the number of chick deaths by changing the pattern of mowing to a more corncrake friendly way. Mowing from the outside of the field inwards killed up to 60% of chicks present whereas mowing in a corncrake friendly way prevented at least two-thirds of these deaths 

These measures were incorporated into a recovery programme in 1992, supported by funding from Scottish Natural Heritage (SNH) and RSPB Scotland. The programme worked to build partnerships between agricultural communities, conservationists, government and agencies to promote these simple ways help corncrakes to crofters. The long-term aim was to increase the size of area under corncrake friendly management in Scotland’s islands and north west coast, as well as halting the long-term decline in corncrake numbers.

By 1998, the programme had demonstrated that the corncrake conservation measures, if implemented at sufficient scale, could reverse declines both at a local and a national level, which was great news. This success prompted SNH and Scottish Government to work with our policy teams to secure longer-term funding through a series of EU-sourced agri-environment schemes. These schemes provide crofters with funding for creating and managing early cover plots, keeping livestock away from corncrake habitats during the breeding season, delay mowing until at least 1st August and mowing in a corncrake friendly way.  

Whilst there has been a reversal in the UK corncrake population with numbers more than doubling since the early 1990s our policy and research work has not finished.  Further studies have been undertaken to identify whether there are potential benefits of corncrake management on other plants and animals, and we found that bumblebees, beetles and plant communities do all benefit from our work helping corncrakes. We also looked into the migratory route of Scottish corncrakes and discovered that Scottish birds undertook a different migratory route to corncrakes breeding in central Europe. Given the benefits of the corncrake conservation measure not just on these rare birds but also other wildlife we’re continue to press government to ensure its sufficient support into the future for the wildlife friendly farmers and crofters that are integral to this work in the Scottish Highlands and Islands.

You can find out more about our work helping corncrakes in this month's RSPB podcast. Keep an eye out for two more blogs still to come this month on these rare birds.