Chough are iconic birds, with striking red bills and red legs. They were once common around the coast of the UK.  Despite conservation efforts, there are mixed fortunes for chough across the UK: chough numbers remain in decline in Scotland. In today’s blog, Nicola Scott, Senior Project Manager at the RSPB tells us about the LIFE 100% for Nature project. One aspect of this ambitious project is to support efforts to enhance conditions for breeding chough across a suite of Special Protection Areas (SPAs) on four RSPB reserves on Islay and Oronsay in Scotland’s Inner Hebrides. 

Chough in Scotland
Chough live in coastal areas with short grassland, now restricted to the west of the British Isles. In Scotland, they are currently only found on Islay, Colonsay and Oronsay. Chough numbers in Scotland are low, with the population having almost halved from over 100 pairs in the 1980s down to 53 pairs in 2014, with numbers continuing to decline. This is due to numerous factors including competition for available nesting sites from other bird species, changes to livestock farming and poor survival of chicks in their first year.

We don’t know exactly why first-year survival rates are low for chough, but congenital illness and a long-term decline in invertebrate numbers (such as dung beetles and their larvae, and ants and their grubs), a key food source for younger birds, are factors.

The striking red bill and legs of the chough in flight. © Tony Blunden (

Conservation grazing
Sheep and other livestock are important on RSPB reserves on Islay and Oronsay, as they graze the grass to keep it at an optimum height for chough to forage. Livestock dung is also an important resource for many of the invertebrates that chough feed on.

To ensure the health and welfare of the sheep, medication is used to prevent and treat for worms, fluke (a parasite affecting livers of livestock) and blowfly. However, some of these medications are passed out in the dung, and can prevent it from being colonised by invertebrates – this means less food for chough

The adverse effect of livestock veterinary medicines on dung invertebrate abundance is well documented through scientific evidence, and so we aim to minimise the unnecessary use of such treatment at reserves where chough are present, such as Ramsey and South Stack in Wales.

Oronsay nature reserve in summer. © Clive Walton.

How are we helping?
Thanks to funding from the LIFE programme of the European Union, we’ve purchased two smart sheep weighing and identification systems. These allow us to keep more accurate livestock records over extended periods of time, with a ‘personalised’ record for each sheep’s weight and medical history. This means we can move away from routine worming and each sheep is given a precise dose of medication, when needed, to keep it healthy and ensure no ‘wasted’ treatment.

The RSPB already uses best practice management approaches for livestock, and these new systems enable us to bolster our knowledge about the flock and further enhance sheep welfare. At the same time, it is reducing our reliance on expensive medications.
We have also constructed three artificial ‘chough houses’ to increase the availability of nest sites.

Through sharing knowledge and experience, it is hoped that others will realise the benefits of using a weighing system in their own operations, and in turn more accurate use of medication can benefit the wider area of habitat for rare birds and other wildlife.

A lamb in the sheep clamp on Oronsay, where we can administer medication. There are weigh bars below the clamp allowing us to weigh each sheep and adjust the dose each time. © Hannah Sharratt.

Early results
On Oronsay, the new equipment is already having many positive impacts, although the long-term effect on dung invertebrate densities isn’t yet known. So far, we’ve been able to reduce the amount of medication used on the flock; from 5,501 ml of wormer used in sheep on Oronsay in 2019 to 741 ml in 2021.

On Islay, we’ve been carrying out specific sheep health testing, such as faecal egg counts (counting the number of worm eggs to monitor the worm burden in the sheep) and blood tests. These tests have helped us to provide more targeted treatment.

As standard, sheep are usually treated at least once or twice for fluke from August onwards. Using the project equipment at RSPB The Oa reserve, sheep were tested on a monthly basis for fluke during autumn and winter 2021. This testing found that treatment for fluke was not required until December, meaning that unnecessary treatments were avoided earlier in the year.

The LIFE 100% for Nature project is ongoing and understanding the longer-term impact of these measures will take time. The project is helping to address some of the pressures on chough in Scotland; part of a bigger picture of management and research into the species, as we aim to stabilise the population on Islay and Oronsay in the short to medium term and avoid any further declines.

LIFE 100% for Nature
LIFE 100% for Nature aims to boost the condition of designated features, like chough, at 11 project locations across Scotland, trialling innovative and up-to-date conservation techniques, to show how Scotland can meet its most ambitious biodiversity targets.

We want to demonstrate how best practice land management solutions can be replicated on areas with important habitats and species throughout Scotland. Projects such as this are vital to show what is possible through transformative land management and conservation techniques to protect and enhance species across Scotland’s protected areas to contribute to vital nature and climate targets at a national scale.

We are able to deliver this project thanks to a generous grant from the LIFE programme of the European Union, NatureScot and many other funders and supporters.

Take a look at our 'Farming for Nature' video, explaining more about how sheep help birds on Oronsay.

Learn more
• Gilbert et al (2019) "Livestock Management in Red-Billed Chough Feeding Habitat in Great Britain and the Isle of Man". Rangeland Ecology & Management, 73(2), pp.216-223.
• Beynon et al (2012) "Species-rich dung beetle communities buffer ecosystems services in perturbed agro-ecosystems". Journal of Applied Ecology. 49(6), pp.1365-1372.
• McCracken and Foster (1993) "The effect of ivermectin on the invertebrate fauna associated with cow dung". Environmental Toxicology and Chemistry, 12(1), pp.73-84.

Continue reading
Making the most of our woodlands – introducing the Woodland Wildlife Toolkit
Slowing the flow - re-wetting woodlands to boost biodiversity
Action for Nature – sharing our stories

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