Guest Blog by Chris Goding, Hodbarrow Field Officer
Following Dave Blackledge’s introduction to the recent LOTE funded habitat works at RSPB Hodbarrow, life at the reserve continues apace. I am one of two Field Officers here over the breeding season, with shared responsibility for surveying adult numbers and productivity of our key species (notably Sandwich, common, and little terns). We also monitor predation events and engage with members of the public about the RSPB’s work at the reserve, its history, and the wildlife found here.
Work was finished on the new island in January this year, complemented by an extension to the eastern side of the main island. The new island has seen modest but encouraging interest from breeding birds, and is currently home to a ringed plover pair (with two chicks) and a single oystercatcher nest as well as 2 common tern nests.
We are hopeful of increased use of the island in future years once the substrate matures. At the time of writing this blog, there are at least 20 common tern pairs on the new extension to the main island, making use of the increased space provided where a small island has been joined to the ‘mainland’, forming a miniature peninsula.
Current trends point to a successful season all round!
The peak count of little tern adults so far this season is 87, with at least 40 pairs, more than triple the number of pairs last year! Twenty six little tern chicks were spotted during a ringing session on the 11th June, the highest count since at least 2017, so we are hopeful of an excellent year for the species here. They appear to be responding particularly well to the application of slag to the concrete surface at their favoured spot, which helps to prevent the accumulation of rainwater around the nests.
Fifty common tern pairs (with a minimum of 40 chicks so far) points to a good year for this species too. Alongside this, at least 300 black headed gull chicks and 200 Sandwich tern chicks means the colony is a busy place.
With time yet for these numbers to increase we are expecting a productive season at Hodbarrow this year.
By Dave Blackledge, RSPB Site Manager - Cumbria Coastal Reserves
RSPB Hodbarrow sits on the edge of the Duddon Estuary in south-west Cumbria. Part of the Morecambe Bay and Duddon Estuary SPA, it was the site of one of Europe’s most productive iron mines in the 19th Century.
As mining operations ceased in 1968, a mixed colony of Sandwich, common and little terns began to nest on the limestone slag by the lagoon formed on the flooded workings. This colony is now of international importance and its position behind the sea wall, protecting the site from storms, high tides and future sea level rise mean it is an integral part of western Europe’s tern network.
Introduction of anti-predator fencing in 2016 immediately reversed the fortunes of the colony after a few years of fox predation, with tern numbers increasing rapidly. In 2018, predator disturbance of the Sandwich tern colony at Cemlyn on Anglesey led to a large influx at Hodbarrow with 1950 pairs, around 15% of the UK population breeding here that year. The fox free breeding islands have also benefitted other shorebirds, with black-headed gulls, eider, tufted duck, ringed plover and oystercatcher all benefitting and increasing in number.
With all this activity concentrated on a single 1.5ha island it became apparent that nesting space was becoming an issue. Little terns in particular, arriving and settling later than many of the other species were being squeezed to the edges of the island, picking sub-optimal nesting sites wherever they were able to find their preferred semi-isolated spot.
Life On The Edge is addressing this problem by creating further protected breeding habitat at Hodbarrow. Around 12500 tonnes of limestone slag from the adjacent slag bank will be dug and transported to increase the size of the current breeding island from 1.5 ha to 2 ha, alongside the creation of a second 0.25ha island.
A further 130m of fencing to protect the new island will also mean that breaching of defences to one island will not give foxes access to the entire breeding area, giving a further level of protection.
Other works include scraping of vegetation and scrub from an artificial flood bank left over from the mining operations. The aim is to provide further nesting opportunities for the SPA designated lesser black-backed gulls along with herring gulls and great black-backed gulls.
The main habitat works on site have progressed well this winter (while complying with the covid-19 guidance) and we now eagerly await the 2021 breeding season to see how the birds respond to the improved and new islands.