A blog post by Irena Tomankova, Conservation Scientist, RSPB Centre for Conservation Science, introducing the Curlew Trail Management Project, which aims to find a solution to stabilising the declining breeding population in the UK.
The Eurasian curlew is one of our most loved birds, with their haunting bubbling calls and long down-curved beaks.
Curlews spend their winters around the coasts of Europe and northern Africa, migrating inland to their breeding grounds in the spring. They can live for up to 30 years and are remarkably site-faithful, so you will often see the same pairs returning to your fields and moors each year.
What's the problem?
Sadly, curlew numbers are declining dramatically across their breeding range due to a reduction in suitable breeding habitat and high predation rates.
Some of the largest declines have occurred in the UK – since 1995, the breeding population declined by 48%, with some of the largest declines occurring in Wales and Northern Ireland.
Despite this, the UK is one of the most important countries in the world for the curlew, with around a quarter of the global population living here in summer, and almost as many in the winter. The UK’s role in saving this species is therefore critical.
What are we doing to help?
In response, the RSPB has initiated a Curlew Trial Management Project. This is a five-year research project which aims to test whether a combined package of targeted habitat management and predator control can successfully recover curlew populations on their breeding grounds.
It involves monitoring curlew numbers and productivity, predator abundance and vegetation across six study areas in the UK – two in Scotland, two in England, one in Wales and one in Northern Ireland. This research is a massive undertaking, entirely dependent on the fantastic support from farmers and landowners at each of the sites.
At each area, we are monitoring two sites of around 8-10km2 each, one of which is the ‘trial’ site (where predator control and targeted habitat management is taking place), and the other is the ‘control’ (which continues on a business as usual basis, to act as a vital comparison with the trial management site).
Every year, one research assistant is present at each area from late March to early September. They monitor the birds, predators and vegetation across each site, so that we can pick up changes from year to year, and assess how birds are responding to the management put in place.
Plans for 2018
As I write this, the fourth field season is in full swing, and research assistants are busy estimating fox abundance across the sites by walking around 20km of designated routes at each site, and recording the number of fox scats (poo) found (believe it or not, a standard method of monitoring fox numbers!).
This enables us to monitor how fox densities change over the course of the project and how they respond to the predator control put in place. Next, they will be conducting bird surveys, recording every bird seen or heard while paying particular attention to curlews and their behaviour.
Then, from mid-July until early September, it’s the vegetation surveys, which involve walking transects spread 100m apart, stopping every 25m and recording dominant species, vegetation height and density.
Using the vegetation and bird data collected during previous years, we found that curlews prefer areas of less dense vegetation, and with moderate rush cover. Therefore the habitat management that takes place before curlew arrive on their breeding grounds is targeting areas with denser vegetation and those with high rush cover.
We hope this approach will be effective and by the end of the project we will know what habitat management and predator control interventions are needed to stabilise the breeding population of curlew.
How can I help?
Donate to our Curlew Just Giving page. All the money will go directly to fund habitat management work, specifically designed to meet the needs of curlew.
The Curlew Trial Management Project is part of Action for Birds in England, a conservation partnership between Natural England and the RSPB.
What has always concerned me about the formulation of this project is how you are going to distinguish scientifically between the relative impacts on productivity of the habitat management and predator control undertaken on the various trial sites. It is highly likely that in some areas one management tool within the combined package will be more effective than the other; in turn, inevitably limited resources would surely need to be focused on the former. But I don't see how the findings of this trial are going to help you determine that definitively, either for the purposes of your own reserves or as advice to other land managers. Furthermore, in those areas where you are satisfied that predator control is indeed necessary, I am not clear how you are going to establish how intensive it must be in order to be effective in significantly boosting breeding and fledging success.
I assume (with tongue in cheek) that the "Strathbraan Community Collaboration for Waders" is not participating in the project. Perhaps SNH would be wise to read this blog "to see what happens" when a proper study is undertaken.