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Biosecurity for LIFE: protecting seabirds from invasive predators

Tom Churchyard, Senior Project Manager at Biosecurity for LIFE, explains how invasive non-native species threaten UK island seabird colonies, and how Biosecurity for LIFE has been working to tackle this threat.

At the height of the breeding season the UK is home to an incredible diversity and abundance of nesting seabirds. Over 5 million seabirds breed around the UK at some of the biggest and best seabird colonies found anywhere on earth. Boasting 90% of the world Manx shearwater, 68% of Northern gannets and 60% of the world’s great skua the UK is globally important for seabirds, however you want to measure it.

Unfortunately, seabirds as a group are one of the most threatened of all birds and face a whole range of pressures including climate change, overfishing, and, the focus of this blog, invasive non-native species.

Invasive Non-native species are organisms that establish in new environments, outside their natural range, and have a negative (and often devastating) impact on the native species present. Species that are only found on remote islands, and this includes many seabirds, are disproportionately affected by this threat, with an estimated 73% of island species facing extinction in the near future if no action is taken.

In the case of seabirds, it is invasive non-native mammalian predators that pose the most imminent threat. Species such as rats, mice, cats and mink have been transported around the world by people either deliberately or as accidental stowaways. These highly efficient predators can devastate seabird colonies by eating eggs, chicks and even adult birds who have not evolved to evade capture or defend their nests from these mammals. It is no surprise that the UK’s best seabird islands are largely mammalian predator free.

Whilst the UK has had some notable successes in recent years to remove invasive non-native mammalian predators from some of our islands, such as rats from Lundy, St Agnes & Gugh (Isles of Scilly) and the Shiant Islands, we have been much slower in protecting predator free islands from the accidental arrival of predators.

We call the actions taken to prevent the accidental spread of a species ‘biosecurity’ and since August 2018 Biosecurity for LIFE has been working hard to implement biosecurity action across all the most important UK seabird islands (42 Special Protection Areas, or SPAs).

We break biosecurity down into three steps. The first of these is ‘prevention’ along pathways, i.e. reducing the ways and means in which a mammalian predator can reach an island. Pathways include the very few natural routes (a brown rat can swim up to 2km) and the various human created routes; shipwrecks, in cargo, yachts, ferries, kayaks, air transport and deliberate introduction. Working with all types of marine user we have helped put barriers to stowaways along these pathways. Training on how to store baggage, goods and cargo and make vessels less attractive to stowaways, the undertaking of pre-loading checks, looking at waste and rodent management around harbour sides and signage so passengers can be responsible by simply checking their own bags before boarding. It may sound unlikely that you could pick a stowaway up, but we have many stories of this happening and if you think about the large number of marine trips around the UK the risk is very real. If you do happen to find a stowaway we have all the information on what to do on our website , but the key message is not to land on a seabird island until you are stowaway free.

The second biosecurity step is ‘early detection’. In the event that biosecurity along the pathway is breached it is important to detect this as early as possible so we can move to step three if needed. Early detection includes the use of continual surveillance tools and devices both on vessels and seabird islands that can pick up signs of a potential mammalian predator. Methods include wax chew blocks that are attractive to rodents that are checked regularly for teeth marks, trail cameras which will detect any animal walking in front of them but can be placed to target any mammal species depending on habitat, and tracking tunnels for footprints. We are working to establish surveillance networks on all the UKs seabird island SPAs to create that early warning in the event of an incursion at any of our most important seabird sites.

The third and final biosecurity step is ‘rapid incursion response’. If barriers on pathways have been breached and an invasive mammalian predator is detected on an important seabird island, then it is important to do something about it quickly before the animal has dispersed widely and started breeding (if pregnant on arrival), and to reduce the impact it could have on a seabird colony. To achieve this, we have set up rapid incursion response hubs around the UK fully equipped to deal with any incursion, volunteers are being recruited to operate these hubs in a similar model to mountain rescue teams with the target of being able to get to an island with a fully-trained team and equipment within 48hours of a confirmed incursion.

Over the course of the project there have been three confirmed incursions (one mink incursion and two rat incursions). Thankfully we were already working in the areas these occurred at and were able to work with local communities to mount successful incursion responses, giving us confidence that this approach can work. Feedback from volunteers engaged in biosecurity action has been overwhelmingly positive.

With the Biosecurity for LIFE project ending in July 2023 we are increasingly switching our attention to how biosecurity will continue to be supported across our seabird islands. The message coming through from the project partnership and our key stakeholders is clear – biosecurity is a shared responsibility, and everyone can have a part to play. We look forward to working with biosecurity stakeholders, including statutory nature conservation bodies, to develop and implement robust legacy plans for the project by next year. Maintaining and improving in the long-term the biosecurity measures our dedicated team and hard-working conservation volunteers and professionals have put in place on islands is vitally important for safeguarding the UK’s internationally important seabird populations. Without biosecurity, we risk losing some of the spectacular seabird colonies on our islands – one of nature’s wonders right here on our shores.


Tom Churchyard is Senior Project Manager at Biosecurity for LIFE.

Follow: @biosecurityLIFE

The opinions expressed in this blog are the author's and not necessarily those of the wider Link membership.