The Wildlife Trust’s islands, Skokholm and Skomer, are home to Wales’ most mysterious sea bird, the European Storm Petrel. The wardens on Skokholm Island have recently built an artificial Storm Petrel wall in order to further support and study the Storm Petrel population on the island.
During the past summer months The Wildlife Trust of South and West Wales, along with a team of researchers from The University of Gloucestershire, conducted the most accurate census to date of the Storm Petrels. The team recorded 1,762 breeding pairs of Storm Petrel on Skokholm which is thought to represent up to 20% of the UK breeding population. A further 205 Storm Petrels reside on the neighbouring island of Skomer, and including non-breeding individuals pushes the total estimated population to nearer 5,000 birds in total in this Special Protection Area (SPA) just off the Welsh coast.
Richard Brown, The Wildlife Trust’s resident warden on Skokholm says “Whether we realise it or not, we all rely on the sea. Seabirds are an excellent indicator of the health of the marine ecosystem, so it is vital that we monitor them closely over time in order to identify issues arising and respond to them promptly and effectively. The Storm Petrel in particular, tells us about a very specific niche in this ecosystem, and these numbers are going to provide a very useful baseline from which we can monitor future trends and react accordingly.”
The majority of Skokholm’s Storm Petrels nest in fragile rock crevices with chambers inaccessible to researchers. This makes these amazing seabirds very difficult to study on the island. With so few accessible sites researchers struggle to answer their simple life history questions, such as what proportion of nesting pairs fledge a chick each year. In the late 1970’s wooden nest boxes were installed in the walls around Skokholm’s Farm, these were later replaced in the 1990’s with plastic nest boxes. Although the plastic did not prove particularly successful at first, we have found that nearly 10% of them have been occupied in more recent years. They do however seem prone to dampness, perhaps due to condensation caused by the materials used.
The Wildlife Trust felt that these nest box designs could be improved further in order to attract a larger number of birds. So, this year has seen Skokholm building a rather special wall near the Quarry. Although it will look like one of Skokholm’s herringbone walls (at least on the one side and the top) it will contain over 100 Storm Petrel nest boxes with access hatches. The wall, adequately named ‘The Petrel Station’, will hopefully encourage breeding pairs of Storm Petrels and replace some of the nesting sites lost from the now crumbling dry stone walls around the island.
Richard Brown continues, “We’re really proud of the new Storm Petrel study wall. It not only provides valuable new nesting sites but will also make studying and counting the Storm Petrels in this area much easier in the future.”