David Hunt, RSPB Scotland's Seabird Recovery Officer, tells us about a trip to Fidra in the Firth of Forth working alongside incredible volunteers to ensure the island remains a happy summer home for our puffin visitors.

Keeping invasive non-native species at bay on Fidra

The origin of the name Fidra, like many other Scottish islands, reveals a strong connection to its natural heritage; Fiðrey or ‘feather island’ in Old Norse. A reminder that this is a place that seabirds have called home for many centuries. The Forth islands, of which Inchmickery, along with Fidra are managed by RSPB Scotland are home to seabirds by the thousands, in internationally important numbers.

Fidra is only a small island, less than a mile off the East Lothian coast but it provides prime accommodation for some of Scotland’s most famous summer residents. Around 1000 pairs of puffins occupy the island between April and August, their breeding burrows dotted across the steeper, grassier areas of the island.

Collectively, the islands of the Forth hold close to 50,000 pairs of puffins but not all is well. Inconceivably puffins are classed as globally vulnerable to extinction by the IUCN. A reduction in food availability brought about by the climate change-induced impacts on the marine ecosystem is thought to be the main driver, whilst invasive non-native species pose serious threats to their breeding success. It was this latter threat that saw me boarding a boat in North Berwick harbour last week destined for Fidra.

In more recent times, Fidra has become home to a far less welcome resident and one that if left unchecked can cause real problems for puffins. Tree mallow, a plant not native to Scotland was first introduced to the Forth over 300 years ago. Believed to have medicinal qualities and of apparent use to lighthouse keepers as…toilet paper, the plant, which can grow up to 3 metres in height, quickly took hold and made its way to Fidra.

close up image of tree mallow
Tree Mallow on Fidra. Photo: David Hunt

So, every September, once the seabirds have departed to their winter quarters and all is quiet again, groups of dedicated RSPB volunteers make the twice-monthly boat journey to ‘feather island’ to stem the tide of tree mallow, which as history tells us can greatly affect puffins by drowning out access to their burrows. During the nineties, the tree mallow situation had gotten so bad that puffin numbers dropped down to 400 occupied burrows.

The solution? Tree loppers, secateurs and lots of tea and biscuits!

As we hopped off the boat at Fidra’s small jetty, a few eyebrows were raised at how high the mallow had grown since the last visit before the seabird breeding season kicked off in March. Again, linked to climate change, increasingly mild winters are thought to be potentially playing a part in the plant’s rapid annual growth. Still, no time to spare, four hours of steady chopping lay ahead.

By the time lunch came around and a chance to assess the morning’s work over a cup of tea, the progress made was visible to all (see below) but as was how much effort would be needed over the winter months to open up as much space as possible for incoming puffins after their winter Atlantic exertions. A quick glance out to sea, sandwich in one hand, binoculars in the other – Manx shearwater one way, red-throated diver the other. The North Sea in autumn a wild and wonderful place.

image shows lots of removed tree mallow
Making progress... Photo: David Hunt

Tools grabbed, it was back to work for one last mallow push but not before our attention had turned to another threat. Invasive non-native mammalian predators, such as rats, mink and stoats, introduced either deliberately or accidentally by humans pose great threats to the success of seabirds, many of whom are found only on islands that are safe from the presence of these predators. Thankfully Fidra has remained invasive mammalian predator free but it is of critical importance that this is continually monitored. Allison Leonard, RSPB Forth Islands Warden and I walked up to the lighthouse on the highest point of the island and batting away some of the densest stands of tree mallow, located a number of small black boxes. These boxes contain flavoured wax blocks, highly attractive to a passing mouse or rat. Passing through the entrance hole, their distinctive teeth marks on the wax blocks provide vitally important  detection clues.  No rodent teeth marks found, only some wax blocks in need of replacement due to an army of earwigs at work!

open black box with wax and mud inside
Biosecurity on Fidra. Photo: David Hunt

The implementation of basic preventative biosecurity measures such as this are considerably more cost effective than dealing with the consequences of an island invasion by non-native predators and ensure seabirds have safe places to breed. The Biosecurity for LIFE partnership project with RSPB, National Trust for Scotland and National Trust is aiming to better equip the 42 UK internationally important island seabird Special Protection Areas (including the Forth Islands) with innovative biosecurity measures than ever before to deal with this threat and build real resilience into our seabird populations.

By the time we made our way down from the lighthouse, our boat was in sight skimming across the waves from North Berwick ready to take us back to mainland. Tools downed, the first session of the autumn had delivered small pockets of ground now free from tree mallow, ready to be expanded upon on another day. The bottlenose dolphins just offshore were a just reward for a hard day’s graft.

The work of volunteers is absolutely essential to the RSPB. Without their time and hard work on Fidra to control the tree mallow every year, puffin numbers would certainly be lower. With every plant that is cut, who knows, we may see more breeding puffins on feather island in the not too distant future. And at this critical time for the species, safe places to breed are exactly what they need.

For another way in which you can help us develop our understanding on how puffin diets have changed over time across the UK, become a member of the Puffarazzi by sending us your photographs of puffins carrying fish.