RSPB Mersehead Blog 23rd – 29th July 2022
Many visitors to Mersehead walk the main coastal trail in a loop around the reserve. The Southwick Water cuts its way west through the merse (saltmarsh) and winds out across the sandflats into the estuary towards Sandyhills. This is a beautiful quiet corner of the reserve and worth the extra walk. As you head out along the merse footpath, you will see the Aberdeen Angus herd grazing the saltmarsh to the right of the footpath. This is the first time in over 20-years that this section of the saltmarsh has been grazed as we aim to address improving the condition of the sward for breeding waders, particularly Redshank, Curlew and Lapwing.
Enjoying the merse.
As you arrive on the beach, head right instead of left. Many botanical coastal specialists can be found in this sheltered corner of the reserve including the regionally scarce Sea Holly and Sea Bindweed. The endemic Isle of Man Cabbage is a bright yellow crucifer easily identified by its distinctive lobed leaves. This plant only grows on the west coast in Cheshire, Cumbria, Lancashire, on the Gower in Wales and in Southern Scotland.
Regionally scarce Sea Holly.
Further out on the merse shades of purple dominant with Common Sea Lavender, Sea Aster and the nationally scarce Lax-flowered Sea Lavender all in flower. Another nationally scarce plant which we have struggled to locate recently has been rediscovered this summer, Seaside Centaury.
Nationally scarce Seaside Centaury.
Sitting in the hides at Mersehead you may wonder where all the water has gone. To provide good breeding and wintering conditions for a variety of wildlife, the wet grassland habitats at Mersehead are actively managed. If left alone, succession will occur; grassland becomes dominated by taller, courser species such as rush, which then succeeds to scrub and eventually you would be looking out onto woodland. To halt this succession, we lower our water levels every summer. This allows cattle to graze the fields to reduce the vegetation length creating ideal feeding conditions for wintering wildfowl such as wigeon. Breaking up areas of dense rush by mechanically cutting will attract breeding waders such as Lapwing in the spring. There are other benefits to drying out wetlands too; if water remains throughout the summer, higher temperatures allow bacteria to flourish which can cause the soil to become anaerobic (no oxygen) and toxic. Plants and invertebrates are unable to survive in these conditions, which is bad news for the ducks and waders that feed on them.
Sunbathing in front of Bruiach Hide.
With temperatures having reached 22oC there have been plenty of insects on the wing. Amongst our usual species list of butterflies, this week saw the addition of two slightly more exciting species. Purple Hairstreak was spotted in the canopy of the oak trees; first discovered on the reserve last summer, this butterfly could have been present much longer but gone unnoticed due to its habit of remaining high up in the canopy. The second species, Small Skipper is a relatively recent coloniser of Scotland. Several dragonflies have been spotted by visitors this week with Golden-ringed Dragonfly, Four-spotted Chaser and Common Darter reported.
Small Skipper.
The moth trap was put on last night as part of the Garden Moth Scheme. Four new species for the year were recorded Scarce Bordered Straw, Cloaked Carpet, Mouse Moth and Straw Underwing. Scarce Bordered Straw is a brand-new record for the Mersehead species list! An immigrant to the UK, this moth is widely recorded in southern England but is scarce further north and throughout Scotland. Cloaked Carpet has been recorded only once previously on the reserve in 2020. Aside from a good population on the Isle of Man, this moth has not been recorded north of Wales.
Cloaked Carpet.
Post breeding flocks are noticeable as birds reappear from their moult during which time adult birds shed their worn-out feathers and grow new, strong warm feathers to see them through the winter. It takes energy to grow new feathers and is a drain on a birds resources. This is the reason why many birds become inconspicuous for a time as they may be more vulnerable to predation. Large flocks of Linnet and Goldfinch can now be seen feeding across the fields and hedgerows. Gathering in large groups means they can work together to identify and share food sources and increase the likelihood of spotting and confusing predators.
Swallows, Sand Martins and House martins can be seen hawking over the grasslands. The majority of the swallows have reared their young now and can be seen lined up along the telegraph wires readying for their departure. British swallows spend their winter in South Africa travelling at speeds of up to 200 miles a day across western France, across the Pyrenees and down eastern Spain into Morocco and then across the Sahara.
Telegraph wires.
With the Mersehead holiday cottages fully booked for summer don’t miss out on the opportunity to stay at Mersehead during the winter months of November and December when the reserve is home to thousands of Barnacle geese and internationally important numbers wintering wildfowl. Check out availability for Shelduck and Barnacle through the hyperlinks.
I had a slight surprise this morning as I was greeted by the Luing herd enjoying exploring the beach. Not a usual occurrence at Mersehead!
Rowena Flavelle, Warden