Welcome to the latest news and updates from the Orkney Native Wildlife Project.
New to our blog and want to find out more about the project, how to volunteer with us or have a question? Visit our Facebook page, our website or email stoatsightings@rspb.org.uk
Final push to complete the trap network
Thank you to the many hundreds of landowners who have chosen to help safeguard the future of Orkney’s native wildlife by granting permission for stoat traps on their land.
As an invasive non-native species in Orkney, stoats pose a very serious threat to our wildlife such as the Orkney vole, hen harrier, short-eared owl and other ground-nesting birds as well as to free-range poultry such as chickens and ducks. Protecting our native species is also important for our economy as nearly half of visitors to Orkney spend time watching wildlife, helping contribute to Orkney’s £70 million tourism industry. A decline in our native wildlife (for example caused by stoats) may also impact agri-environment funding available for Orkney farmers who currently get more points for being in a priority area for wildlife. Orkney’s nature has never been more important in supporting the health and wellbeing of those who live on the islands during this pandemic and is vital to protect now and for future generations. For more information about how the project it is benefitting wildlife, communities, tourism and the economy, follow this link.
Hen harrier (female/juvenile) by Christine Hall
With 757 landowners now supporting the project, our trap network currently covers just over 70% of the land in Orkney Mainland and the linked isles – 78% coverage in East Mainland, 73% coverage in South Ronaldsay and the linked isles and 67.6% coverage in West Mainland. We still have some very important gaps to fill in the network and we hope the final 30 or so landowners will get in touch to grant us permission for traps to be placed on their land to enable our team to complete a robust eradication network. We are also trying to identify areas of land where owners remain unknown or where they are under common grazing. The Project is aiming to have secured land access and deployed all trap boxes by the end of this year so if you think you can help, please get in touch by emailing us at stoatsightings@rspb.org.uk.
Stoat by Steve Sankey
Radio Orkney postbag
A Radio Orkney listener asked a great postbag question recently about why we are not using GoodNature A24 traps from New Zealand for stoat eradication. We are!
For over a year we have been trialling 267 GoodNature traps on Special Protected Areas (SPAs) in Birsay and Orphir which are protected areas for rare and vulnerable bird species such as red-throated divers, hen harriers and short-eared owls. GoodNature traps are incredibly useful here as they only need checking every six months, meaning we can minimise visits and not disturb these sensitive species during the breeding season between March and September.
GoodNature trap by Sam Ranscombe
GoodNature A24 traps were designed in 2005 as a humane rat trap, but they are also able to catch mice and stoats. The traps are small, light, and easy to move and use, giving an instant and humane kill. They self-reset up to 20 times and use a long-life bait, so require less frequent checking. The bait we are currently using is a chocolate lure which is designed to be particularly attractive for stoats!
So why are we not using GoodNature traps instead of the DOC 200 traps that are housed in wooden boxes? GoodNature traps are quite a new product, originally designed for rats not stoats, so we want to trial them first to measure how successful they are. To do this we have set cameras opposite some of the traps to record what is being caught and we will be checking this footage over the winter. The cameras have also been picking up some surprise appearances by native wildlife species including a short-eared owl, a merlin and a snowy owl in Evie!
Snowy owl caught on camera trap
Trap stats
We realised that we have become a bit irregular in sharing stats about what the traps are catching, so each month or two we will be bringing you some trap stats to update you on the project progress so far. Here are the first ones:
September 2020
October 2020
Project total so far
Trap boxes active
1874
1894
2047
Trap box checks done*
2908
2572
22407
Stoats caught**
82
109
750
*many trap boxes contain two traps
**the stoats are killed using a type of lethal, humane trap – the DOC 200 – which is approved by the Spring Trap Approval Order for Scotland and the UK and meets the welfare standards defined by the Agreement on International Humane Trapping Standards (AIHTS).
For more details about the trapping network and why some of our traps, particularly in West mainland are currently closed see our previous Stoat Snippet 92.
Stoat carrying a vole at The Loons by Martin Lever
Despite extensive efforts to try to prevent it, all eradications will kill some animals that are not the target species – this is called bycatch. We are taking all possible measures to ensure as few other animals are killed as possible: the trap safety boxes that house the DOC200 traps have been designed with small entrance holes (60x60mm) which should exclude larger animals. The traps are calibrated to trigger on the weight of the lightest free-ranging young stoat (approximately 100g) so lighter animals shouldn’t spring the traps. We also use baits and lures selected to attract stoats. The only non-target animals that we cannot minimise catching are brown rats as they are a similar size and weight to stoats and are attracted to similar baits.
You’ll maybe remember from early snippets that we caught quite a few rats during the development phase of the Project and since eradication trapping began in 2019, the traps have killed 2068 rats over 20,424 trap box checks (or more than 35,000 trap checks as most boxes have two traps in).
Unfortunately, our efforts to minimise catching animals that are not stoats are not always successful. Over the same 20,424 trap box checks where the 2068 rats were caught, the traps also killed 242 rabbits, 111 starlings, 2 blackbirds, 2 water rails, 4 small cats, 10 voles, 48 mice, 18 hedgehogs, 9 frogs/toads and 12 unidentifiable small birds and rodents.
We realise that this will be deeply upsetting for many people. It is for us too. But we are committed to learning from these incidents and taking prompt action to make any adjustments that could further reduce the chances of catching other animals.
We are particularly sad that four small cats were killed this summer because we thought we had taken adequate steps to prevent this happening. In 2017, despite the safety measures in place, a pet cat got its paw caught in a trap during the Project’s development phase trapping trial. The cat went on to make a full recovery, but we immediately changed from using standard to extended trap boxes to prevent an inquisitive cat being able to reach the trap mechanism from outside the trap box in the future.
An extended trap box without the wire tie
There had been no further incidents until this summer. We want to reassure people that these incidents are incredibly rare (four out of more than 35,000 trap checks) and that we acted immediately to try to reduce the risk further. Following catching the first small cats, we started making further adjustments to the trap boxes, first by adding additional wire mesh and then by adding wire ties to reduce the size of the external entrance holes from 60x60 mm (2.4 inches tall and wide) to approximately 60x40 mm (1.6 inches wide). This should further reduce the chances of catching other animals while still allowing large stoats to enter the trap boxes. We are rolling this out as an additional safety measure prioritising boxes near houses.
Extended tunnel with wire tie added (20 pence piece for size comparison)
While we cannot promise that we will never catch anything that isn’t a stoat, we can promise that we will do everything we can to minimise the chances.
We can also promise that we will continue to learn from each incident. Orkney has quite a lot of feral cats and we’ve been unable to confirm if any of the cats killed were pets despite searching lost pet pages on social media. So, we’ve purchased a microchip scanner and will knock on doors or contact folk living nearby to help us discover if there is a missing cat. These measures will be used by staff, if needed, as part of a strict protocol to ensure the Project is being open and transparent.
We are also planning to continue to share figures about what else has been caught by the traps as part of these regular updates.
While it may not provide much comfort, the Project would not have been able to happen if it was predicted that the eradication would cause more harm than good to our native wildlife. During the Project’s development phase, the potential impact of catching other animals was investigated as part of an independent feasibility review. This concluded that, for species of conservation concern, the numbers caught in the traps would be too small to affect their populations in Orkney and also that the impact of stoats would far exceed the impact of efforts to remove them.
Stoats are very skilled hunters and have high metabolic rates meaning they need to eat up to a quarter of their bodyweight a day to survive. This amount increases for females during the breeding season to up to two times their bodyweight. And stoats often kill more than they immediately need if opportunities arise.
Not eradicating stoats will cause irreparable change to Orkney’s natural environment and have devastating impacts on Orkney’s native wildlife with internationally and nationally important populations of ground-nesting birds (from curlews to Arctic terns to hen harriers) and the unique Orkney vole all threatened. Given the importance of wildlife for our individual wellbeing, our culture and our economy, the cost of not eradicating stoats would be too great.
Curlews at Brodgar by Alan Leitch
Conservation dogs delayed due to England lockdown
Covid-19 lockdown restrictions announced in England this week have sadly delayed the arrival of the first three of our conservation dogs coming up from Kryus Limited in Merseyside. In Stoat Snippet 91 we told you more about the six dogs that are being trained and our three dog handlers and how they will detect stoat signs and smells to indicate presence. As there are currently no stoat detection dogs in Europe, their arrival in Orkney is very exciting and we can’t wait for Thorn, Riggs and Spud to join the team! Thank you Kryus for sending photos to keep us going until then.
Spud the stoat detection dog by Kryus Ltd