RSPB Mersehead Blog 24th - 30th July 2021

The Mersehead team has grown with the recent arrival of Luke and Amy, who have joined us as residential volunteers.  We are very pleased to welcome them,  and they will be playing a vital role in assisting with both habitat management and visitor engagement over the coming 7 months.

We saved some ragwort for a new residential volunteers. Photo credit: P. Radford

Over the past week, they have experienced first-hand how interesting, varied and challenging the work we do at Mersehead can be.  With the hay now made and safely stored away before some rain finally fell for the first time in over two weeks, the focus moved to preparing more fields for grazing, and moving livestock to ensure we gain the maximum benefit from our hungry four hooved friends.

Another satisfied customer. Photo credit: P. Radford

Like many habitats, wetlands benefit from grazing with cattle as a means of controlling rank vegetation, encouraging wild flowers and creating the ideal conditions for a number of key species.  Mowing removes vegetation unselectively, and results in an even sward, whereas cattle will preferentially eat certain grasses, leaving many flowers and creating an uneven sward height (and bare muddy areas) which will support nesting waders and invertebrates. 

Before we can graze the Mersehead wetlands, we need to erect a temporary fence to keep the cattle to a safe area, and also install a water trough.  These two tasks were completed on Tuesday by our dedicated team of local volunteers, with a barrier also being installed to protect valves and pipe work from the heavy beneficiaries. 

Erecting a temporary fence in the wetlands. Photo credit: P. Radford.

Protecting the water supply. Photo credit: P. Radford

Those enjoying the stroll down Rainbow Lane to the beach will also soon see cows grazing out on the merse.  In addition to the benefits cattle provide on a wetland, livestock are much better suited to traversing the creeks and gullies that would make mechanical control hazardous and time consuming.  A section of the merse has now been prepared, which also means turning on the electric fence; another good reason to keep to the path and ensure dogs are under control.

Mind the fence. Photo credit: P. Radford

The fine weather has been ideal for monitoring butterflies, and for the third week in a row over 150 individuals were recorded on the fixed transect that we walk as part of the UK Butterfly Monitoring Scheme.  Ringlet (3) numbers have dropped, but Meadow Brown (52) and Green-veined White (93)  are still dominating the count.  Three other species – Small Copper (6), Common Blue (2), Small Tortoiseshell (3) ­– where also recorded on the route, which covers an array of habitats across the reserve.  

Common Blue and Small Copper butterflies. Photo credit: L. Jones

Whilst not encountered on the survey route this week, Peacock and Speckled Wood have also been spotted, along with three Painted Lady Butterflies.  A very faded specimen has been welcoming visitors to the Wetland Trail by the Sulwath Garden, and two much fresher individuals have been spotted at opposite ends of the reserve.  This really is an extraordinary insect, being one of a handful of butterfly species that migrate to the UK from North Africa, central Asia and the Middle East.  As a result of the many factors that can affect the number that reach the UK, it is no surprise that numbers vary considerably, with a once in a decade phenomenon when unusually high numbers of butterflies are seen in the UK being described as a ‘Painted Lady Year’.

Peacock and camera shy Painted Lady butterfly. Photo credit: P. Radford

You don’t need to commit to walking a weekly transect to help monitor the abundance and distribution of butterflies in the UK.  The Big Butterfly Count, organised by Butterfly Conservation, is running from 16 July to 8 August, and involves counting butterflies from a single location for just 15 minutes. 

Getting a closer look. Photo credit: P. Radford

Despite the pools and ditches now being almost completely dry,  a walk along the Natterjack ditch still resulted in 26 toadlets – of variable size – being recorded.  Dragonflies also thrive in this area, with Common Darter and Four-spotted Chaser being abundant.  We also inadvertently surprised a female Shoveler with 3 young, who quickly dashed for the cover of the sea club rush.

Natterjack ditch looking a bit dry. Photo credit: P. Radford

Moth numbers – both seen during the day and in the trap – continue to benefit from the warm days and nights.  At the time of writing, a number of moths still need to be identified from the weekly moth trapping session, but it was another bumper week with the final species count expected to be  between 40 and 50, with at least 160 individuals recorded.  The array of sizes, shapes, patterns and colours is always awe-inspiring, but this week the moths have offered further fascinating moments.  Including witnessing a female Drinker Moth laying her hard, white eggs, a gang of Antler Moths feasting on ragwort, and the curious a sight of a male Small Phoenix with its abdomen pointing up high above its wings.

Spot egg beneath the wing of the Drinker Moth. Small Phoenix. Antler Moths on ragwort. Photo credit: P. Radford

Whilst this is a time of year when the smaller inhabitants take centre stage, there are still opportunities to spot and photograph birds on the reserve.  Common Buzzard have bred in the woodland, and the cry of their young is now regularly heard here.  If you are not too distracted by this you may be lucky enough to spot the Tawny Owl that is often roosting along to same path.  Not only did Steven Weatherley see both these species, but he got some fantastic photos which he has kindly shared.

Common Buzzard. Photo credit: S. Weatherley

Tawny Owl. Photo credit: S. Weatherley

The Lapwing which bred at Mersehead moved on a number of weeks ago, but a few sightings of juvenile birds this week was followed by the discovery of a large mixed flock of around 55 adult and young birds in a recently ploughed and reseeded field beyond the woodland.   This is likely to be a moulting flock, which may have arrived from the continent, and are just making one of what could be several stop-offs on route to their over-wintering grounds. Presently they are having to share this arable field with 5 Canada Geese, a Roe Deer and a large number of Starlings and Rooks.  Who knows what else will arrive over the coming weeks?

Lapwing, Canada Geese and Rooks. Photo credit: P. Radford

Paul Radford, Assistant Warden