Mersehead Recent Sightings 12th September - 18th September 2020

A calm and settled start to the week brought pleasant relief from the relentless winds that swept across the reserve over the weekend.  With the temperature rising and the sun making a welcome return, conditions were just right to conduct a survey of the butterflies and bees that have made Mersehead their home over the summer.  Walking the fixed transect, which takes in the full array of habitats, was a very quiet and peaceful experience on this occasion.  Most of the cattle and sheep have now returned to their winter homes, but have left the grasslands in good condition for the Barnacle Geese, whose imminent return we eagerly await.

Dry Grassland at Mersehead ready for the Barnacle Geese. Photo credit: P. Radford

The number of pollinating insects seen naturally declines as we move into autumn and winter, as the plants and flowers on which they forage die back.  The bumblebee nest will follow suit, with the queen bee being the only survivor as the colony reaches the end of its cycle.  She will subsequently leave the nest to seek out a suitable winter hibernation site.  Butterflies have more than one strategy for surviving the cold winter months, depending on the species.  However, like the bees, the majority enter at state of dormancy.  Small Tortoiseshell – of which good numbers can still be seen around the reserve – spend the winter as adults, and may be spotted routing around in buildings for hibernation sites.  In contrast, the adult Large White do not survive much beyond September, but the caterpillars that have been feeding up on brassica over the summer (and making themselves unpopular with vegetable growers), will enter the pupal phase of their life cycle, with the aim of spending the winter as a chrysalis before emerging as an butterfly in the spring.

Small Tortoiseshell on Sea Radish. Photo credit: P. Radford

Four species of goose are commonly seen at Mersehead – Canada, Greylag, Pink-footed and Barnacle.  There are populations of Canada and Greylag who are resident in the UK, which would explain why they are amongst the earliest to be seen, as they move the relatively short distance from breeding to wintering grounds.  Pink-footed geese have travelled significantly further, having made an arduous migration from Iceland and Greenland to reach these shores.  With large numbers being seen and heard flying over the reserve this week, the indication is that many are on the verge of completing this journey. 

Pink-foot Goose. Photo credit: Andy Hay (rspb-images.com)

It is relatively easy to identify these four species on the ground, but it isn’t so straightforward to pick out distinguishing features when a large flock (known as a skein) appears as a silhouette high in the sky.  Fortunately, the different species offer some helpful clues in their call, flight formation and wingbeats.

Greylag and Pink-footed are species of grey goose, which are associated with the classic V-formation and fly with slow, purposeful and elastic wingbeats.  Pink-footed geese are smaller than Greylag, and have a proportionately smaller head and shorter neck.  They are also more likely to be observed migrating in large, tidy v-shaped skeins that the Red Arrows display team would be proud to emulate.  The Pink-footed has a high pitched, jovial and musical call, whereas the Greylag call is deep, and a mix of cackles and honks.

Pink-footed goose in V-formation. Photo credit: P. Radford

Canada and Barnacle are both black geese, but the Canada goose is almost twice the size and has a long, swan-like neck and black forehead.  Apart from being considerably smaller, Barnacle Goose has a completely white face and a small, delicate bill.  Both species have a black neck, but for Barnacle this colouration extends to the upper chest, whereas it stops abruptly at the base of the neck for Canada.  In flight, the size and powerful wingbeat of the Canada Goose is more reminiscent of swan, with Barnacle Goose having more similarities with the slow beat of a small grey goose.  Although these two black geese also form V- and U-formations, smaller flocks of Canada Goose will often fly one behind the other.  Barnacle Goose are seen in large skeins, but they tend to appear untidy, with flocks splitting into long bands each flying at different levels.  The high-pitched ‘bark’ of the Barnacle Goose is far-reaching, whilst the deep, resonant Canada Goose call rises in the second syllable and is more reminiscent of a trumpet.

A visit to Mersehead over the coming weeks will provide plentiful opportunities to view and listen to these majestic birds as they feed on the dry grassland fields and roost on the mudflats, and surely there is no better way to experience the sight and sound of thousands of Barnacle Geese than by booking a winter Mersehead break at BARNACLE or SHELDUCK cottage.

Making the most of the relative peace and quiet, the melodious song of the Robin can be heard in surround sound along the length of the hedgerows and around the farm buildings.  At least 8 could be seen and heard early one evening on the short stretch between the byre and Sulwath Centre.  The Robin is one of the few passerines in the UK that can be heard singing in autumn and winter.  One popular theory for this is that, unlike other farmland birds that flock to locate and share food sources, the Robin is establishing its own feeding territory which it is willing to aggressively defend.  Interestingly, it has also been shown that female Robin also sing at this time, and although visually inseparable an expert ear can pick up subtle differences in the male and female song.

Robin. Photo credit: Ben Andrew (rspb-images.com)

Habitat work this week has focused on the wetlands, with reed, rush and low lying vegetation being cut so that, when the sluice boards are put in and water levels rise the ideal feeding conditions will be achieved for the array of dabbling and diving wildfowl – including Teal, Wigeon, Mallard, Shoveler and Pintail – who are currently waiting patiently at the large pool in the field adjacent to Rainbow Lane

Wildfowl waiting for the wetland water to arrive. Photo credit: P. Radford

Although the hides remain closed at this time, creating expansive views across the wetland has been another key focus of the work.  Raking and removing cut reed, loading willow into a trailer and removing the temporary wetland grazing fence are all back breaking tasks which our volunteers helped considerable to complete on a hot and humid Tuesday this week.

Preparing the wetlands. Photo credit: P. Radford

The tractors then moved in to finish the job, with the work being overseen by a Peregrine Falcon, four Common Buzzard and a Red Kite.

Tractor topping in wetland. Photo credit: P. Radford

If you are keen to help out and volunteer with us, we are looking for more help for our visitor experience work. As we move towards a return to opening facilities and/or ways to engage visitors, could you get involved? If so, please contact Calum Murray by email (mersehead@rspb.org.uk) or message us on Facebook @RSPBMersehead.

Our visitor centre and viewing hides remain closed to visitors, as is the Sulwath Garden and children’s play area. However, we are currently trialling the re-opening of a toilet at the visitor centre, for visitor use.  This is open every day between 10am and 4pm.

In the mean time, we hope you can continue to visit and stay safe at this time, while following Scottish government Covid19 guidelines. Please keep updated about the re-opening of RSPB reserves and facilities at: Reserve Reboot

Paul Radford, Assistant Warden