RSPB Mersehead Recent Sightings 24th –30th April 2021
Talking about the weather is a favourite British pastime, but more than being a convenient topic of conversation, at Mersehead a constant eye on the forecast is needed to both plan our work and offer some explanation for what we are seeing and hearing around the reserve.
An area of low pressure has seen daytime and night-time temperatures plummet, partly due to the associated cold northerly winds. The strength and direction of the wind may explain why, as of Wednesday’s count, still over 1,000 Barnacle Geese are huddling in dense flocks at Mersehead. Whilst this is down significantly on the 6,000 counted the previous week, it was still expected that they would have all left by now, to start their 2,000 mile journey to the Svalbard breeding grounds.
With over 20 Lapwing nests now established it is getting a little crowded and, despite being significantly smaller, devoted parents can regularly be seen chasing off any goose that stumbles too close to the nest. We now know of three nests that have successfully hatched, and with the help of a scope and lots of patience have spotted a total of 8 chicks.
Assuming the geese vacate in the next month, there will then be plenty of room for the herd of Belted Galloway cattle who are joining us in June. Local contractors completed the work on the required cattle fence this week, which has been a joint effort with staff and volunteers.
Surely this new fence isn't too high to keep the geese from heading to Svalbard? Photo credit: P. Radford
The warbler section of the Mersehead choir has been bolstered by some new additions this week, with the first Common Whitethroat arriving. Their scratchy song can be heard at various scrubby points around the Wetland Trail, especially at the start of the hedgerow just past the Sulwath Garden, and before dropping down onto the beach after exiting the woodland. This is also a good spot to listen out for distinctive song of the aptly named Grasshopper Warbler, whose numbers have increased over recent weeks. Monday’s reedbed survey also revealed that Sedge Warblers have also now arrived to breed in the reedbed. However, their off beat eccentric blasts of song can also be heard at a few spots around the trails. This song contrasts with the more rhythmic, less harsh song of the Reed Warbler, who have also started to arrive from their African wintering grounds.
Sedge Warbler. Photo credit: P. Radford
The discovery of Natterjack Toad spawn strings last week prompted the first full adult toad survey of the year on Saturday night. With the wind making it feel bitterly cold, we were not hopeful of finding much. However, our spirits were lifted by hearing the unmistakeable ‘fishing reel’ call of the male toads, which gives this iconic Mersehead resident its name. In fact, the noise emanating from the breeding pools was almost deafening at times. Mersehead were early pioneers of this type of survey, which aims to understand population dynamics by locating, identifying (male or female) and measuring the toads. This approach was originally introduced to help understand the impact of a tidal surge in 2014, which washed out the dunes where the natterjack toads were thought to be hibernating. In addition to the measurements now taken, a more accurate picture of the population was determined by identifying individual toads by their unique dorsal wart patterns. This study, over three years, revealed that rather than being wiped out, the population was thriving. After recording 104 toads on a cold, windy night, we hope that the signs are good for similar conclusions to be drawn this year.
We're going on a toad hunt. Photo credit: P. Radford
Natterjack toads can only be handled in the presence of a licence holder. Photo credit: P. Radford
Discovering evidence of breeding activity naturally leads to looking for spawn strings, with searches now being conducted twice a week. The aim is to identify new strings and monitor the existing strings, so we can track their progression from spawn, to tadpoles and then to toadlets. Toadlet emergence is the key factor in determining the future health of the population, as 2021’s toadlets will be the breeding adults of 2024.
Spawn string hunting: much like toad hunting but without torches. Photo credit: P. Radford
Left - a new natterjack spawn string, with appearance of double rows. Right - after a day or two the spawn form a single row. Photo credit: P. Radford
Rainfall has been severely lacking so far in April, and is vital to the survival of natterjack spawn strings, which tend to be found in the shallow water at the edge of the breeding pools. If these dry out, the strings become stranded and will fail. It has therefore been a welcome change to experience the sweet smell of petrichor. Yes, it turns out there is a name for the earthy smell released when rain hits dry soil and plants, which is partly due to the plants producing a compound that accumulates between rocks and soil during dry weather.
The low-pressure system not only affected the winds, but also the tides, which were caused to rise much higher than expected on Tuesday and Wednesday. Seeing the salt marsh at Mersehead inundated led to concerns for the Curlew, Redshank and Oystercatcher who would be attempting to nest on similar habitat at Kirkconnell Merse. A dawn survey at Kirkconnell on Thursday finished off the first round of breeding wader and wildfowl surveys, and full pools across the merse provided evidence of the flooding we had feared. However, witnessing the mesmerising and vocal parachuting display flights of curlew and redshank gave hope that all may not be lost.
Evidence of flooding at Kirkconnell Merse. Photo credit: P. Radford
One plant that flourishes in the muddy salt marsh creeks both at Kirkconnell and Mersehead is Scurvy Grass. Both English and Danish scurvy grass are native to the UK, and get their name from being rich in vitamin C, which along with a preference for coastal habitats resulted in this particular genus of plant being eaten to counteract scurvy, which afflicted sailors due to a lack of vitamin C during long journeys.
Scurvy grass at Kirkconnell Merse. Photo credit: P. Radford
It hasn’t been the ideal weather for insects this week, and whilst bumblebees and butterflies are slowly growing in numbers, it is nice to be able to feature a solitary bee thanks to a volunteer and his niece, who between them photographed and identified a stunning female Andrena haemorrhoa (orange-tailed mining bee). As their name suggests, solitary bees differ from social bumblebees by not forming colonies to forage for food to feed the offspring. Instead, the female lays a single egg in a number of cells, which are then filled by her with pollen and nectar before being sealed. The larva then eat, pupate and emerge as an adult the following year. In the case of mining bees, these cells are created in underground tunnels, with the orange-tailed favouring south facing grassy slopes. Homes for solitary bees can be easily created in your garden by just drilling holes in pieces of wood, tying together bamboo canes or, if you are feeling more adventurous, have a go at making a bee hotel.
Female Andrena haemorrhoa (orange-tailed or early mining bee). Photo credit: D. Jackson
The weather may be causing headaches for the wildlife, but has not been putting off our visitors, and it has been great to see familiar and new faces this week. Just a reminder that more of our facilities are now accessible: hides are now open for limited numbers in keeping with social distancing rules, and the festival hut will be open with a staff member/volunteer on hand to welcome you to the reserve, point you in the right direction and answer all those questions! Please note that the car park charge of £3/car for non-RSPB members has returned to help the RSPB to continue to protect the wonderful wildlife at Mersehead. Come and chat to us at the festival hut if you are interested in becoming an RSPB member.
Although the Visitor Centre will remain closed, the toilet will be available from 10am-4pm.
Our two Holiday cottages Barnacle and Shelduck are have reopened – we have limited availability left for 2021, so click on the links now to secure a booking.
Paul Radford, Assistant Warden