Saturday, 6 October 2018

Bath Nats Primrose Hill 16th September 2018


Report of visit to Primrose Hill 16th September 2018
A group of four revisited Primrose Hill to repeat the biodiversity measurements begun in 2012.  It was an autumn day after a dry summer which will have not helped the growth of our target organisms.  There were many visitors to the site (plus dogs).  We found that there had been much clearing of the undergrowth and dead wood with the brush wood burnt and the larger pieces stacked as in good practice so passage though the wood was easy.  We recorded the presence or absence of so-called lower plants (bryophytes, lichens and fungi) in 20 x 4 m radius circles.  The position of the circles was determined by our random generator (Alan R).  One unexpected complication was that despite notices at the gateway asking people to take their dog faeces home with them it was almost impossible not have them in our circles so pollution we thought might be high!  This is not the only place in Bath where this happens (try the Linear Pathway!) but it was I thought the worst.
The site was established in 2000 on an arable field so we would expect that there would not be any bryophytes lichens and fungi on site (or at least not woodland ones) so starting from zero we have data from 12 and 18 years after establishment.  We did not expect to find any real rarities but you never know.  In fact we did find some less common bryophytes such as Cololejeunea minutissima (Minute Pouncewort) a tiny epiphytic liverwort growing on Field Maple and Fissidens incurvus  (Short-leaved Pocket-moss) on soil.  Surprisingly a small piece of stone lying on the surface yielded two species not encountered anywhere else in our sampling: Tortula muralis (Wall Screw-moss) and Eucladium verticillatum (Whorled Tufa-moss) the latter of which is very small. For comparison we have data from an 18 year old coppice at Lower Woods, an ancient woodland site In Gloucestershire.
Below are the different scores from these three samples:

    Primrose Hill 2012                     Primrose Hill 2018                         Stanley 2000
Species Richness             4                                                        16                                      17
Simpson’s Index of
Evenness                           2.99                                                  9.69                                   17.62
Species Conservation
Value Index (rarity)         2 (=/-0)                                             2.75 (+/-0.75)                   4.04 (+/-1.53)
Frequency (colonies)      40                                                     115                                    244
Nitrogen Index
(pollution)                         6.2                                                    4.94                                   4.68
The picture emerging from this is that after a time sites are colonized by common species and that the distribution of these colonies increases in time. Rarer species are part of this colonization. There is some amelioration of the nitrogen pollution from the arable field but the dogs are doing their best to slow this down. Stanley is similarly dogged by dogs.
We will be repeating this in the future when this will become an increasingly fascinating experiment.  We have several other sites under observation that we hope to visit in the future.
May thanks to Alan and Marion Rayner for their unflagging enthusiasm with identifying  “lower plants” and Kate for her care recording of the field data

Monday, 1 October 2018

Fabulous Fungi at East Woodlands, Bath Nats meeting on Wednesday 5th September 2018


Beefsteak

A group of nine of us gathered under the magnificent veteran oak trees outside East Woodlands Church on a morning that began coolly but became increasingly warm and sunny towards lunchtime. As in 2017, and despite the hot, dry early-mid-Summer weather, we had a real fungal treat awaiting us, easily making a list of over 60 species.

We began by finding a variety of fungi growing underneath and upon the oak trees. These included several ectomycorrhizal fungi - Scaly Earthballs (Scleroderma verrucosum), some Xerocomus cisalpinus boletes and Sepia Brittlegill (Russula sororia), and two bracket fungi - Beefsteak Fungus (Fistulina hepatica) and a magnificent Oak Bracket (Inonotus dryadeus).  Then we made a quick diversion into the churchyard to examine some fine growths of Squirrel-tail Moss (Leucodon sciuroides) on a tombstone.
Squirrel-tail Moss


As we made our way along the byway towards the beech-wooded Roddenbury Hill, we stopped briefly to examine some beautiful freshly emerging specimens of Beefsteak Fungus, as well as some colourful Purple and Scarlet Brittlegills (Russula atropurpurea and Russula pseudointegra). On and around the hill we encountered numerous Ceps (Boletus edulis and B. reticulatus) and Blushers (Amanita rubescens), Scarletina Bolete (Boletus luridiformis), a variety of Brittlegills, Small Stagshorn (Calocera cornea) and  Grey-spotted Amanita (Amanita excelsa). 
Small Stagshorn


We then took the path downwards into the very different wet woodland habitat of Lower Woods. Here, as in 2017 we came across two outcrops of perhaps our most exciting find of the day, the deep pink jelly fungus called Salmon Salad (Guepinia helvelloides).
Purple Brittlegill
Salmon Salad



Tuberous Polypore


Alan Rayner

Photographs (By Marion Rayner and  John Garrett)






Thursday, 28 June 2018

Bath Nats trip to Caen Hill Locks/Kennet & Avon Canal Side Pounds, Devizes: 23 June 2018:


Leader: Lucy Delve
Eleven members gathered in the Caen Hill Locks car park in glorious sunshine; the leader had high hopes of finding Scarce Chaser dragonflies, and lots more besides.
Emperor
Scarce Chaser
The first dragonfly species seen was a male Emperor hawking over and the side pound close to the top of the locks. Searching through the dense foliage around the side pound, we found a froglet, a Scarlet Tiger moth (there seem plenty around at the moment) a nymph of a Dark Bush cricket, and many Blue tailed damselflies, with a few Azure and Common Blue damselflies.  A Stock Dove coo-ed unseen in the tall trees adjacent to the towpath as we walked down to the next side pound.
Swifts swooped low, occasionally taking a drink, and I noted only one Swallow. Other birds using this habitat included Tufted Duck, Mallard, Mute Swan, Moorhen, Grey Heron. We had a blue-flash of a Kingfisher as it darted passed us at speed, disappearing in the vegetation in the next side pound as we wandered down the grassy path adjacent to the Diamond Jubilee Woodland.  In the hedgerow, Alan R drew our attention to a Great Mullein plant which was, not unsurprisingly, hosting a number of Mullein moth caterpillars. I was lucky to be looking up whilst we gathered for a short break around midday to see a Red Kite drift over the trees and most members saw the bird if only very briefly. Butterflies seen in the area included Meadow Brown, Small Tortoiseshell and a very obliging freshly emerged Ringlet.  Rob R identified a striking looking Soldier Fly (Oxycera rara).
Soldier Fly (Oxycera rara)
I spotted smaller dragonfly being harassed by the Emperor and recognised it as a male Scarce Chaser, with its pale blue abdomen.  We found several more as we explored more side pounds, some insects traversing the grassy paths between the pounds and landing on nettles. We could see that the male had mated with females, showing the distinctive grey copulation marks down each side of their abdomen.  Rob R and some other members had a good view of an orange-brown female. I had mistakenly identified a brown dragonfly among the male Scarce Chasers as a Four spotted Chaser. However, studying my field guide after the meeting, I read that the females will darken to a dull brown colour; I did see briefly a male chaser joined to, presumably a female, darting over the water. A lone Four spotted Chaser in this habitat was unlikely!  The Brown Hawker flying around us as we continue walking down the grass slope was unmistakable! Keeping around the side pounds, we located two singing Sedge Warblers and spent some time listening and watching one of them at close quarters. Within its varied song, I could pick out mimicry of the songs and calls of Blue Tit, Goldfinch, Swallow and Yellow Wagtail.
We returned to the car park via paths through the Diamond Jubilee Wood, noting Ragged Robin, Rough Chervil, Fleabane and Grass Vetchling.  I located a male Yellowhammer at the top of a tall tree by song and we could approach the bird, so intent on making its presence known. Other birds heard here included Common Whitethroat and Blackcap and it was good to see a male Kestrel among the soaring Buzzards.
Yellowhammer 
Mullein moth caterpillar

LD






Saturday, 9 June 2018

Bath Nats trip to Pewsey Down on 26th May 2018.


Expectations were high in the weeks leading up to this trip to the chalk hillside of Pewsey, as the trip last spring was awesome....but as 15 of us assembled in the Wiltshire Wildlife Trust car park at the base of the Downs, we were not too confident of a good day!

The skies were grey, the wind was on the cool side, to put it mildly, and a few spots of rain were in the air. Unperturbed, we set off through the kissing-gate, and up the hill, where we’d had such great views of Orchids and Butterflies last year. Alas, though we searched, and spread out across the hill-top, we didn’t even see a single Butterfly, and only 1 Early Purple Orchid! Spring was running about two weeks later than usual, and boy, did it show!
I did however manage to find a spider that was new to all of us...a female Larinioides cornulus, the Funnel Spider!
Whilst we took an early lunch, a single Marsh Fritillary landed on a bare patch of earth behind Lucy, so everyone rushed to see it...but some members were not fortunate and thought they their chance had gone, due to the weather!

But, good things come to those that wait....and as the sun broke through and the cool wind dropped, we aborted our decision to leave early, and made our way down the hill and around to the warmer, chalky, south-facing side. On the way Alan showed us a small patch of Clustered Bellflower and we saw the caterpillar of the 5-spot Burnett prior to it changing into its chrysalis stage.

The sun was now out, and it became very warm indeed, and as we followed the narrow chalky paths along the hillside, we were rewarded for our patience in spectacular style!

Over 100 (maybe many more) Marsh Fritillaries we’re out, including mating pairs amongst the males and females, and thousands of Garden Chafers were flying around and courting in the grass. The Butterfly sightings began in earnest, with Green-Hairstreak, both Dingy & Grizzled Skippers, Brown Argus, Small and Common Blue, Small Copper, three Whites, including Green-veined, and a Wall-Brown...all in all a total of 13 species seen by all of us!

We were also fortunate to find a few moths, though not the profusion of Forester Moths that we had last year.
This time, sharp-eyed Steve found a Small Elephant Hawk, and a freshly emerged Fox Moth also gave good views. 5 moth species were counted, including a Common Heath and Five-spotted Burnett, also freshly emerged. Also Alan pointed out, among the Birds-foot Trefoil and Rock Roses, patches of beautiful blue Chalk Milkwort.

So, after initially thinking we would have to abort our field-trip early, it was so good, that we all ended up staying another hour!

Thursday, 7 June 2018

Bath Natural History Society web site


Bath Natural History Society web site is under reconstruction and therefore not up to date, sorry for any inconvenience. You can contact the Society at info@bathnats.org.uk

Sunday, 20 May 2018

10 May 2018 Bath Natural History Society Field trip, Ham Wall and Shapwick Heath


 Leader Lucy Delve
Nine members gathered in the Ham Wall car park for a 9.30am start on a fairly breezy morning, after a very short delay for a passing rain shower.  From then on there was ever-decreasing cloud and we enjoyed viewing and listening to birds, among other wildlife, under sunshine and a brilliant blue sky. We spent some four hours in the Ham Wall reserve and about two hours on the Shapwick NNR reserve later in the afternoon.
Most members attended the meeting with the express desire to learn how to identify birds by their songs and calls, so I concentrated on that.  We studied several warbler species including Willow, Garden Warbler and Blackcap. It was useful to have a Sedge Warbler singing in close proximity to a Reed Warbler so as to hear the differences in pitch, speed of delivery and variation in the complexity and variety of notes and phrases. The Sedge is a great mimic. You can stand and listen to its song for several minutes and detect other bird calls including Blue Tit, Swallow, Skylark and Yellow Wagtail. Indeed, we watched Marsh Harriers, Great White Egrets and wildfowl including a Great Crested Grebe with a stripped “humbug” youngster on its back, against an almost continuous cacophony of Garden, Willow and Reed Warblers. It was great to see good numbers of Swifts, at last, and as the morning progressed and the temperature rose, greater numbers of Hobby appeared. Probably an estimate of around 30 at the end of the day would not be unreasonable.  Bitterns boomed occasionally and some members were lucky to have a reasonable flight view of a bird low over the reeds opposite Viewing Platform 1.  Two male Cuckoos seemed to be competing with each other, calling from either side of the old railway track for much of the morning, but quite distant.  However, one called briefly from trees close to the path, not far from the railway bridge, and I was lucky to see the bird fly across the track not far in front of me.
Other notable birds seen were a Little Ringed Plover and a small flock of Black-Tailed Godwit on the scrape on the Shapwick reserve. Glen M located a male Garganey (summer visitor) and we had great views of this most attractive duck from the grassy track leading to the Avalon Hide, from where we saw several male Marsh Harriers at close quarters. Unfortunately, a young Tawny Owl did not feel inquisitive during our visit  - there is an owl nest box on the edge of the woods and during my visit    on 8th May, one of the youngsters was looking out of the hole!  We saw three distant Cattle Egret from Viewing Platform 2, and around 1.45pm during our picnic back at the car park pools, one Cattle Egret flew low across towards Shapwick.
As we watched and listened to birds, we also delighted in many butterflies including Orange Tips and Peacocks and damsel and dragonflies including Azure Damsel and Hairy Hawker. Such insects were still low in numbers.
Glen totalled up 68 bird species seen and/or heard for both sites.
Lucy Delve

Thursday, 12 April 2018

Saturday 7 April WARTH AND RIVER SEVERN WALK

Bath Natural History Society

 Aust (Leaders : Tom Pinckheard and Lucy Delve)
Only 4 members plus the leaders braved the grey morning day with the forecast of initial heavy rain. However, we were immediately rewarded with a pair of Kestrels hovering above us, Meadow Pipits and Skylarks were singing and a couple of Swallows dashed past.  At 10am, we departed for the New Passage at Pilning, avoiding a sudden down pour, at a rising high tide which usually brings in waders and ducks. The rain conveniently stopped. In the distance on the grass, many Shelduck and Curlews could be seen with a few Canada Geese. We then walked around the coastal path towards Severn Beach where species seen and /or heard included Linnet, Dunnock, Starling, House Sparrow, and Chiffchaff in the coastal scrub and many Oystercatchers and Shelduck above the tide line. We returned to the New Passage to the walk along the Northwick Warth grassy path, past an inland pool which yielded many water birds, in particular, a flock of about 50 Redshank, a Little Egret, many Gadwall, Shoveler, Tufted Duck and Teal. On our return walk, Lucy heard a brief snatch of Willow Warbler song and the bird was soon picked up visually; a newly arrived bird from Africa.  She also identified a small group of Redpoll flying overhead. We then drove to Shirley’s Cafe in Severn Beach for a welcome drink and home-made cake and to use their very smart Scandinavian style toilet shed. After this break, we returned to our original starting point at Aust Warth for lunch as the clouds 
cleared and at last the sun appeared. After lunch, spent listening to Skylark and Meadow Pipit songs, we walked towards the M48 suspension bridge past Aust cliff again hearing and seeing Willow Warblers and Chiffchaffs in the trees. Tom P went all the way past the fossil hunters to the bridge and saw a very bedraggled and injured bird of prey crouched unmoving at the bottom of the cliff. Tom’s photograph showed it to be a Peregrine. On the way back, by amazing coincidence, we met a group of fossil hunters lead by Ed Drewitt, the well-known Bristol Peregrine expert, who said he would collect the bird and see if it could be saved. We spent the rest of the afternoon at Aust Warth waiting for a sighting of the short eared owls which had been reported several times this week by the Severnsidebirds blog; the birds roosted in the long grass during the day, emerging to hunt in late afternoon, around 5pm. As we waited and scanned the grassy area, we found a couple of male Wheatear, battling for ownership for a nearby log. Unfortunately, no owls were seen by the time our last car left at 17.00, not helped by dog walkers and a man flying his drone. The total bird species count was 54.
(TP and LD )

Saturday, 24 March 2018

21st March 2018 Bath Nats meeting at East Harptree Woods.



P.brumalis
T.ochracea 




Twelve of us gathered on a cool but quite sunny morning, with snow still lingering in drifts and patches from the heavy fall the previous weekend. As we set out for our morning exploration of the woodland in the vicinity of Smitham’s Chimney, we were quickly rewarded by the sights and sounds of a gathering of Siskins, Goldfinches and Bramblings amidst the branches and tops of the larches and spruces near the car park. Then, a few hundred metres down the main track, we turned right, down into the wet willow woodland where a profusion of bryophytes decorated the banks, wet hollows and tree trunks and branches. Amongst these were the tiny fuzzy growths of an unusual liverwort, Fingered Cowlwort (Colura calyptrifolia). On the other side of the track was an old moss-covered wall on which a good variety of some of the larger common species could be seen, including some beautiful cushions of Swan’s-neck Thyme-moss (Mnium hornum) covered in sporophytes. Here we also stopped to examine some coppiced hazel branches bonded together by the Glue Crust fungus (Hymenochaete corrugata) and the first of several large groups of Scarlet Elfcup (Sarcoscypha austriaca) which add such extraordinary colour to the woodland floor at this time of year. After lingering reflectively by the pool in front of Smitham’s chimney, our next port of call was a    moss, lichen and fern-covered old wall, on the way to which we found large amounts of frogspawn lining the partly frozen puddles along the muddy track. We enjoyed lunch sitting on a bank overlooking Chew Valley Lake in the distance and, in the foreground the lead-rich ‘gruffy ground’ in which the rare and tiny Lead-moss (Ditrichum plumbicola) has one of its very few sites in the UK. Sadly, we couldn’t find it on this occasion. After lunch, we bravely ventured down the steep hill – knowing that we would have to climb back up it – to the magical hidden world of Harptree Combe. On our way, we encountered a troop of Winter Polypores (Polyporus brumalis) growing on decaying wood, then a flock of sheep and lambs, some of whom found us of great interest. Once there, on a decaying tree trunk, we found a large gathering of Ochraceous Turkeytail (Trametes ochracea). A solitary Windflower (Anemone nemorosa) foretold of Spring to come, and amongst the luxuriant carpets and tufts of bryophytes were Big Shaggy-moss (Rhytdiadelphus triquetrus), Dwarf Neckera (Neckera pumila) and Greater Featherwort (Plagiochila asplenioides). All that now remained for us was to climb steadily back uphill past the now disinterested flock of sheep and lambs that had distracted us with their attention on the way down. By the time we reached the car park, deep in conversation, our naturalists’ appetites had been well and truly satiated.

Alan and Marion Rayner

Photographs by Marion Rayner


Saturday, 17 February 2018

11-2-2018 Trip report Bath Nats field outing to Ham Wall RSPB .


Inline image

Bath Nats field outing to Ham Wall RSPB on 11th Feb 2018. 
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Hi all,

Please accept this as the trip report for last Sunday's field outing to Ham Wall. 

"Four of us decided to make 'a day of it' and leave for Ham Wall at 9.30am on Sunday morning. 
We arrived around 10.15 in freezing conditions, and braced ourselves against frequent squally showers of sleet and hail as we made our way down towards the 1st viewing mound on the reserve. 

We saw our first Great White Egret, hunkered down in the reeds, and watched the many Teal, Pochard, Shoveler and Tufted Ducks feeding in the lagoon and along the reed margins. Coot with their attendant Gadwall showed well, and many Water Rail gave away their positions in the Phragmites by squealing like stuck-pigs as we passed! 

We crossed the path, and made our way towards the Loxton Marsh trail, looking for the reported Ring-necked and Ferruginous Ducks, but though we scanned for quite some time, we were without luck, but contented ourselves with cracking views of a Kingfisher and around 15 well-camouflaged Snipe. 

The Tor View hide didn't offer much else, so we made our way along the track and down the very muddy path to the Avalon Hide. Here a sharp-eyed Terry spotted a fly-by Bittern, and another Great White Egret, before we spotted a pair of displaying Peregrine and three {1 male & 2 female} splendid Marsh Harriers over the reed beds. A Sparrowhawk added to our Raptor total as it weaved speedily along the tops of the Gorse out on the levels. 

As the clouds parted and the sun came out, we decided it was time for some lunch, and to meet the other members who were due to turn up around 2.00pm in the car park. 

Once we'd all eaten, it was time to welcome the other eleven hardy souls who'd come out to brave the blustery, cold, though dry and sunny conditions, and return to the marsh on the Ham Wall side. A couple more Marsh Harriers were seen, but soon it was time to leave Ham Wall and make out way into position over the road at Shapwick Heath, where we had been told that the Starlings had moved to over the last week or so. 

While the cold wind whistled around our ears, and while we waited for dusk to arrive in clearing skies, we took refuge in the Noah's Hide for about an hour, where Terry picked out a distant Whooper Swan, which we all got brief, though satisfying views of. 

Then at approximately 5.00pm, the Starlings started to arrive.....in their thousands, and for the next hour we watched, with many other people, a fantastic murmuration, that wove patterns across the sky in failing light, until they all funnelled down into the Reed bed at 70 Acres. 

A perfect end to a very cold, though top day out!" 

Hope this will do. 

Regards,

Glen. 



Field Trip on Wednesday 21st February: SHIRE VALLEY, nr Marshfield

Extra parking for Field Trip on Wednesday 21st February: SHIRE VALLEY, nr Marshfield. Should anyone arrive on Wednesday to find the limited car parking already taken, continue driving up the hill (assuming you came from the A420 Marshfield direction) and take the first right. Please park carefully on this road, north of the valley and don't block access ST.785.770.