RSPB Mersehead Blog: 19th - 25th March 2022
What a glorious week! High pressure, low winds and cloudless skies have led to woolly hats and gloves being discarded, and replaced by sun hats and sun glasses. The energising power of our favourite ball of hydrogen gas has sparked a flurry of activity across the reserve.
One thing I have noticed this week is that our favourite hedgerow birds, who have been such good friends over the tough winter months as they forage in flocks and keep an eye out for predators, have now become sworn enemies. Wrens chasing each other through the hawthorn hedge and Chaffinches in tumbling aerial battles have been providing entertainment akin to being an innocent bystander during a bar brawl. Wrens are often described as being secretive, but that is definitely not the case when they are establishing and defending territories. It’s therefore a great time of year to see them darting low amongst the scrub.
"If you're not sure where you can go, read the sign". Photo credit: P. Radford
Many of the birds seem oblivious to the presence of binocular wielding onlookers, with one Dunnock in particular treating us to a chorus of uplifting song whilst perched high on the hedge by the woodland. It is not only song that can be used to keep others off your turf and impress the females, as a Great-spotted Woodpecker has been demonstrating at regular intervals. The purpose of rapidly drumming on the trunk of trees is to declare their territory and advertises their presence to others. This individual is doing a particularly good job, as you can hear him as soon as you leave the car park.
Dunnock. Photo credit: Ben Andrew (rspb-images.com)
Whilst the Lapwing continue to display (both aerially and on the ground), the game of cat and mouse between the warden team and the pee-wits is now underway. Our aim is to identify and monitor nests from a safe distance using scopes, but apart from the difficulties posed by undulating ground and vegetation, if the lapwing sense what they perceive to be a danger to their nest they will nonchalantly walk away to lead your attention elsewhere. This diversionary behaviour (which can sometimes be as extreme as faking a broken wing), is one explanation for how a flock of lapwing came to be known as a ‘deceit’.
A photo from 2021 showing the position we hope to catch the lapwing in. Photo credit: P. Radford
Butterflies and bumblebees are especially grateful for the glare of the sun, as it warms flight muscles and enables them to fly, feed and mate. A swirling dance of three Small Tortoiseshell was a particularly welcome sight this week, and queen Buff-tailed and Tree bumblebees have been out gorging on pussy willow and other early nectar providing plants, as they build up reserves at newly acquired nest sites ahead of producing the first crop of worker bees. Bumblebees cope better than butterflies in cooler temperatures, as they can employ another tactic to raise the temperature of their flight muscles to the 30 degrees Celsius level which is require for flight. They are able to detach these muscles from the wings, and shiver to raise the temperature of the thorax – which shows the benefit of performing warm up exercises!
Small Tortoiseshell butterfly. Photo credit: P. Radford
The Bumblebee Conservation Trust provide lots of information about bumblebees, including tips on identifying the different species and castes, and ideas for creating bumblebee friendly habitats, and which are the best foraging plants. At Mersehead, we take part in a monthly BeeWalk to record abundance and species that are present across the range of habitats on the site. The fine weather was ideal for completing our first BeeWalk of the season this week, with queen Buff-tailed and Tree bumblebees being recorded. The bees are especially fond of some flowering shrubs in the Sulwath Garden, including a Japanese Skimmia (Skimmia japonica), which has been alive with bees and hoverflies recently.
A (hard to spot) bumblebee enjoying Skimmia Japonica. Photo credit: P. Radford
The hedgerows are also starting to transform in the Spring sunshine, with Blackthorn bursting into white flower. If, like most of us, you sometimes struggle to tell the difference between Blackthorn and Hawthorn, now is the perfect time to distinguish between the two. Blackthorn flowers appear before the leaves emerge, whilst hawthorn doesn’t blossom until the leaves have appeared. So, at the moment, if it’s white it’s probably Blackthorn and green more likely to be Hawthorn.
Blackthorn and Hawthorn. Photo credit: P. Radford
Regular volunteers often send in photos of things they have seen, and it’s great to be able to feature these in the blog. Last week we featured a stunning male Pintail, and this week a theme has emerged as two photos of Common Toads in amplexus have been shared with me. To avoid any accusations of favouritism, I have included them both. In fact, comparing the two photos demonstrates some of the key similarities and differences between individuals of the same species. Firstly, the variability in size of the adult toads – especially the males. Males are generally smaller than females, and will be on top during amplexus. Amplexus is the name attributed to the type of mating behaviour exhibited by some externally fertilising species – including frogs and toads. The male grasps the female with his front legs (in both photos this is under the armpits), and fertilises the eggs as they are released from the female’s body. As toads lay their spawn strings in pools, I hope our photographers didn’t interrupt the journey of their subjects for too long! You can also clearly see that the colouration and pattern of warts is different for every toad. It was this fact that enabled staff and volunteers at Mersehead to identify and monitor individual Natterjack toads, to established detailed population dynamics following the tidal surges that washed away large sections of the sand dunes in 2013/14.
Common toads in amplexus. Photo credit: Fiona Moir (L) and Dave Jackson (R)
Other sightings of note this week include the first report of a Northern Wheatear, one of our earliest returning migrants. These birds return to the UK from central Africa each year, and stop at Mersehead before continuing to their breeding grounds. They will next pay us a visit at the end of the summer on their way back to Africa. A Weasel was also spotted, as it broke cover from the hedgerow and scurried across a gateway.
Paul Radford, Assistant Warden
Announcements
Flooding
Please note that Mersehead nature reserve is prone to flooding during periods of high rainfall and/or strong winds and tidal surges. To avoid disappointment at these times, please contact the reserve in advance of your visit by email in the first instance at mersehead@rspb.org.uk or check the RSPB Dumfries and Galloway Facebook Page for daily updates.
Holiday Cottages
Planning your 2022 holidays? Discover the breath-taking scenery, wildlife, cultural and history of Dumfries & Galloway whilst staying in one of the Mersehead cosy semi-detached holiday cottages – Barnacle and Shelduck – located in the heart of reserve.
Covid Advice
Please follow our advice on Covid restrictions and updates on our website: https://www.rspb.org.uk/our-work/rspb-news/news/stories/coronavirus/reserve-reboot/