2022 Winter Meetings
28 January 2022 Bats by John Drewett
John is a member of the YNHS and has been studying bats for over 30 years. He explained that bats use echolocation to move about and to locate their prey. This was only discovered by Donald Griffith, an American zoologist, in 1938-1944, through a series of experiments. Humans cannot hear the ultrasonic sounds that bats emit when they are hunting at night for insects and so we need to use hand-held bat detectors to identify them. The bat detector makes the sounds audible to our ears.
Different species of bats emit a different pattern of sound, so an expert is able to distinguish between bat species. John showed us photos of many of the different species found in Britain. Some roost in barns or the lofts of houses, in small cracks in brickwork, stonework or behind fascia boards. Others roost in caves. They are sometimes found in tree holes or behind bark.
Examples of bat species in Britain: Common Pipistrelles, Soprano Pipistrelles, Long-eared, Brandt’s, Alcathoe’s, Natterer’s, Noctules, Daubenton’s, horseshoes and Barbastelles. Bats feed on insects such as midges, but a few of the larger bats prey on moths too. The bats themselves are predated on by cats and also by owls, particularly Tawny Owls.
Bats and their roosts were first protected in Britain by the Wildlife and Countryside Act of 1981, when it was realised that bats were declining, often due to loss of suitable habitats and human interference. The use of pesticides caused a massive drop in insects that the bats depended on for sustenance. Exterior lighting on houses could cause bats to desert their traditional roost sites.
Voluntary bat groups were set up to provide general education to the public and also to help with monitoring and research. This has helped to build up a picture of where different species can thrive and ways in which habitats can be managed to slow and hopefully stop the decline of these mammals. Bats can also sometimes be recognised by sight in the hand, but a special licence is necessary in order to handle them.
There are still many challenges to safeguard the bats of Britain. Climate change may enable a greater diversity of bats to come to Britain, but rising temperatures could also disrupt the hibernation of the bats. Loss and fragmentation of habitats such as removal of hedges, remains a challenge to those who wish to protect our bats. Many thanks to John for this most informative presentation.
Report by Chris Meek
25 February 2022 “Recording Flowers of the Northern Dales” by Linda Robinson
The members of the Society were treated to a wonderful PowerPoint presentation by Linda Robinson, the botanical recorder for North West Yorkshire. She took us on a delightful floral journey from the tops of the Pennine Fells, through the hay meadows and river banks of the Tees, Swale and Ure. She described how plants and trees had recolonized the barren area after the last Ice Age and then brought us up to the present day with the discovery of new species and introductions from other countries. These include Alpine Cotula; an Australian plant found colonising an area near a cattle grid and Danish Scurvy Grass, which forms a white carpet on heavily salted roads. Her photographs then showed us remnants of the wild woodland, now sadly depleted and under threat from disease like the Junipers of Teesdale. Man’s influence has also had its effect on the flora of this region. Old Hazel and Alder trees gnarled and knotted from coppicing for charcoal, to mined areas, where minerals in the ground have produced distinctive flora such as Spring Sandwort, Moonwort and Thrift. She went on to talk about the famous hay meadows of this area, many now lost, and showed us why Yellow Rattle is important. Its parasitic nature inhibits grass growth and allows wild flowers to thrive. Limestone screes, crags, bogs, woods and riverbank flora were also covered in her photos along with rarities such as Teesdale’s Spring Gentian and Leyburn Glebe Field’s Burnt Tip and Green-winged Orchids. Linda Robinson ended with an invitation to join her on her botanical forays (website BSBI.org).
Report by Paul Hardhill
25 March 2022 “Flies Undone”
A talk about Hoverflies, Soldierflies and other goodies in the Fly Group
Who knew flies could be so interesting? YNHS member Derek Whiteley gave such an enthusiastic presentation on Friday 25th March. Armed with his stage props, a sweep net and pooter, he declared hoverflies to be his favourite group. As a student volunteer with Sheffield Museum he was instructed in 1975 to go out and collect flies and by the early 1980s he had initiated a recording scheme feeding into the National Database. This now has more than a million records, documenting over 7000 species of Fly. Of 300 British hoverfly species, 172 have been recorded in the Yorkshire Dales. His choice of recommended guidebook is British Hoverflies, by Stuart Ball and Roger Morris.
Wafting a sweep net over various types of vegetation, in woodland, rural and urban settings and then placing the net over one’s head, selected specimens can be sucked up with a pooter, examined and identified either by naked eye or with the help of a microscope. A beautiful collection of photographs illustrated Derek’s engaging talk. These demonstrated how hoverflies mimic bees and wasps but do not bite or sting. Defined by their wing venation and by having fine hairs rather than bristles, they are often brightly coloured and very common in gardens. The adults drink nectar for energy, so they visit flowers and are superb pollinators. Their larvae have a voracious appetite for aphids. A few specific hoverfly larvae can be a pest to some plants. Other habitats include ancient and rotten trees with holes, pooling water and oozing sap, also animal dung. Nationwide most are in decline, but some are expanding their northward distribution, perhaps a result of climate change. Derek is setting up a Hoverfly recording scheme for the Yorkshire Dales and is keen for us to report finds. He made particular reference to the Giant Bellflower Picture Wing, our local fly, found to date, only in the Yorkshire and Derbyshire Dales. Mention of different soldierflies was also made, they can be found in a wide variety of habitats.
Some of the superb slides were captioned by musical lyrics from various bands. The audience were encouraged to identify the songs, at which we were somewhat useless, but it all added to such an entertaining evening.
Report by Deborah Millward
30 September 2022 Swifts by Jonathan Pomroy
Members were enthralled by the lecture given by Jonathan Pomroy, an artist, author and a Swift fanatic. Fascinated since childhood by Swifts, Jonathan has studied and painted them ever since. His home is shared with multiple Swift and House Martin nest boxes which give ample opportunity for serious research on this strangest of birds. A bird which feeds, sleeps and mates in the air. A bird which only ever touches down onto earth to brood eggs and for six weeks feed nestlings. A bird which flies thousands of miles every year to grace our skies and thrill us with their screaming gangs of juvenile “fly pasts”.
Nest box cameras reveal what, to our minds, is a loving caring little family spending their nights preening one another and communicating in soft twitters. And yet, at just six weeks old, as dusk approaches, the young leave this shelter, spread their long wings for the first time and launch themselves into the night sky. They head straight for Africa, never touching ground again for two years until they are mature enough to breed themselves.
Jonathan’s understandable passion for these birds was contagious. His paintings of Swifts and the skies and landscapes they inhabit were inspirational. Long may Leyburn look after its Market Square colony of these endangered (RED listed) birds which bless our summer shopping.
Report by Deborah Millward
28 October 2022 “Nature Miscellany” by Joyce Scott
Joyce Scott gave us a stunning presentation entitled “Nature Miscellany”. With artistic and informative images she talked us through her fascination with the beauty of nature. Fly Agarics and Fluted Bird’s Nest Fungi featured, alongside lichens such as Xanthoria parietina and Platismatia glauca. Slime moulds also featured in this section of Joyce’s talk.
Cross sections of the stems of the wild flowers of Field Scabious, Red Campion and Yellow Toadflax revealed the intricate microscopic world and beautiful patterns found in flower stems. Oak leaf spangle galls and fungal-induced galls such as Alder Tongue were explained to us, again illustrated with superb macro photos. Tardigrades, also known as Woolly Bears, were collected from her garden pond and photographed. Their translucent bodies allowed us to see the red algae that they had been consuming, inside their stomachs. Some of the images were magnified by hundreds or even a thousand times.
Birds such as Blue Tits and Long-tailed Tits gathered on lichen clad branches and Red and Grey Squirrels were featured too. Joyce then moved on to some landscape shots of the NE coastline and proceeded to give us a fascinating insight into the life of the rock pools in this region. Starfish, sea squirts, sea slugs, sea anemones, sea mats, shells and seaweeds all featured in her amazing photographs.
We were amazed by her tenacity and the patience needed to photograph all these unusual specimens and her extensive knowledge of the natural history of the UK. A table full of shells and pressed seaweeds, brittle stars and minute crabs was inspected before and after the talk and reference books were on display for us to peruse. After a cup of tea and biscuits at the end of the evening, we all travelled home, inspired yet again by the beauty of nature.
Report by Chris Meek
25 November 2022 by Dr Anne Readshaw
Covid 19 disruption once again caused changes to the Society’s calendar and thankfully a member, Dr Anne Readshaw, stepped in with an excellent talk on biodiversity and roadside verges in particular. After a brief autobiography Anne discussed her voluntary work for Plantlife and Friends of the Dales. It was the latter organisation that had initiated her research into roadside verges.
With the ever increasing intensification of agriculture giving fields of mono-culture, biodiversity in many areas was restricted to roadside verges which acted as wildlife refuges. Anne explained that to maintain a rich and diverse growth of wildflowers in verges is essential to support an equally rich fauna of insects. In turn insects were important food for farmland birds and essential for humans too as pollinators of food crops.
Managing verges is not easy. To protect verges from reverting to rank grass and scrub they need cutting, preferably once a year in September, so that flowering herbs are not crowded out. Ideally the cut material should be removed so flowering plants are not buried in rotting vegetation. However this is fraught with difficulties, not least the labour involved, but also the material itself poses disposal problems as it is often contaminated with bottles, cans and plastic debris which prevent successful composting. A compromise solution is to cut twice a year so that the quantity of cut material is small enough to rot in situ without harming the plants beneath.
Earlier research initiated by the National Park had identified stretches of species rich verges in the Dales and these were the ones to target for special treatment.
Report by Deborah Millward
16 December 2022 “The Natural History of Christmas”
Derek Whiteley presented a slide show based on the book “The Magic of Christmas” by the late Patrick Harding. It looked at the plants, animals and fungi associated with Christmas. Starting with the animals thought to be present at the birth of Christ, and the natural history of gold, frankincense and myrrh, then moving on to the evolution of St. Nicholas from a fourth century Christian bishop to the current Santa Claus and the parallel evolution of the British “Father Christmas”. We explored the connection between Professor Clement Moore’s 1822 poem “A Visit from St. Nicholas” and northern Eurasian culture involving the hallucinogenic Fly Agaric mushroom, leading to the concept of flying (female) Reindeer and a secret visit down the chimney by an elf-like St. Nicholas. Many plants associated with Christmas were discussed. Holly, Ivy, Mistletoe, Norwegian Spruce, Nordmann Fir, Christmas Rose, Christmas Cactus, Poinsettia, Cranberry (and North American species), Brussel Sprout, Glastonbury Thorn, Fig, Blackthorn (Sloe), oranges, apples, pears, pomegranates and the latest tree ornaments from Europe – gherkins!
Christmas birds, fish and mammals included Mute Swan, Grey Heron, Pheasant, Turkey, Peacock, Wild Boar, Sturgeon and Conger Eel as traditional food; White Storks, goats (as Dark Helpers) and Brown Bear in Eastern Europe; and the unique place held in Britain by the Robin as a harbinger of Christmas greetings, as Father Christmas’s year round watcher of children’s behaviour, as the bird that fanned the embers of the Nativity fire, and its melodic song and close presence in our gardens during the winter.
Sales of the latest revision of Patrick’s book were donated to his legacy fund to provide educational and conservation activities relating to trees and fungi at Longshaw. The talk stimulated much discussion and anecdotes, and was followed by a delicious Christmas buffet provided by members, with optional sloe gin.
A merry way to end the YNHS year.