The commitment of last summer’s seabird team persisted this winter, as they've transitioned into a dedicated species recovery force.  Now in March, puffins, Manx shearwaters and storm petrels will soon return from their far-flung oceanic wintering grounds and their prospects for raising chicks on two uninhabited islands might be brighter. We may have cleared the last rats from these islands… in the nick of time.

Following the successful removal of rats from St Agnes and Gugh in 2013 to protect both Manx shearwaters and storm petrels from predation by rats. This winter we shifted efforts to clearing rats from the uninhabited islands of St Helens’ and Round Island as both islands are important for burrow-nesting seabirds, including puffins on St Helen’s.

Put simply when rats are present, puffin, storm petrel and Manx shearwater chicks are highly unlikely to survive. At the time of writing this report we are incredibly close to successful rat clearance. Only a handful of rats remain, but to clear the last remaining rats requires skill and patience.

The window for rat removal falls between October and March, coinciding with the period of least availability of alternative food sources for rats. This timing increases the likelihood that rats will be attracted to and consume rodenticide bait. Bait stations must be strategically placed at intervals of every 50 meters, corresponding to the territory size of a rat. Continuous fresh bait replenishment is essential to ensure that rats feed on the bait, this demanding task requires a team navigating the challenging terrain, often braving adverse weather conditions.

The field team carrying out this work consist of dedicated staff, residential volunteers and local volunteers. We thank Tresco Estate and Tregarthen’s Hotel for providing residential volunteer accommodation this winter to make this project possible. Special thanks to the boat skippers from St Agnes Boating and Tresco Boating, ensuring the team get on island as much as possible in what has been a particularly stormy winter. We also thank the seabird partnership, with funding from Natural England and support from RSPB.  As wildlife conservationists, removing rats may not come easy, so the goal of seabird recovery has remained the focus; over 200 chicks across three seabird species may survive this year if rats are cleared!

The techniques employed in this winter’s rat clearance will also contribute to our understanding of how to plan and deliver similar large-scale projects. There is a growing aspiration to remove rats from the inhabited islands, St Martins, Bryher and Tresco, but because rats simply swim between islands this can only be done during the same winter period and the work must include the nearby uninhabited islands too. The knowledge gained from every boat landing and bait station placement on St Helen’s and Round Island this winter is instrumental in future planning.

So now, in early March, spring migration brings Manx shearwaters, storm petrels and puffins ever closer to Scilly for the breeding season. When they return to their burrows, rats will predate them, their eggs and also chicks instead of eating the rodenticide bait, so this is when we must stop all rat clearance work and remove all bait stations. As we enter the final race to clear the last rats from St Helen’s and Round Island, we remain focused to succeed in protecting our seabirds…in the nick of time.

Wish us luck.