Reports

Society Of Biology Western Branch Christmas Lunch 15 Dec 2011

The branch Christmas event was held as a lunch this year at the University of Bristol Veterinary School at Langford in North Somerset. A canteen full of lively students welcomed us and the staff had set aside a private table for the society. An excellent meal of three courses was provided which everyone enjoyed.

Jenna Stevens-Smith came down from London to the lunch and members were delighted to have a chance to discuss with her some of the initiatives the society is involved in.

After the meal we were able to listen to a talk by Professor Peter Holt who recently retired from the Veterinary School. His talk was “My life as a vet”.

He surprised his audience by explaining that his career choice was rather unexpected since he was the first in his family to go to university. He had not really thought about being a vet. Supportive parents, a helpful careers teacher and the wisdom to seize an opportunity gave him his start.

Early on as a young vet he was offered the chance to work in Africa and again took the opportunity which led into a period of challenges both with animals and some people. During his time there he had to sort out an elephant with an injured leg, a wounded jackal and later an aggressive Sarus Crane.

With so many vets on the TV these days it might be taken for granted that wild animals can be dealt with as a matter of course. In fact as Peter illustrated many hard and often dangerous lessons have had to be learnt to make it look so easy!

Back in the UK Peter took an interest in reptiles and was among the pioneering vets at a time when the profession was more focussed on domestic, farming and equine species.

Again we now take it for granted that exotic creatures can be treated and cured and are perhaps unaware that much difficult and challenging work was needed in the early days. Peter described how to operate on and then repair a tortoise which is not so easy when you have to open and then reseal the shell.

Peter rounded his talk off with some stories around his years at Langford and we had a chance to look at some horse bladder stones which were small egg size making everyone wince at the thought of a poor animal carrying those.

Overall Peter’s talk was illuminating and inspirational and made an excellent and robust talk for a biology Christmas lunch.

Mark Howard, Branch Chairperson, Western Branch.

Society of Biology Westonbirt Arboretum Field Meeting May 2010.       

Committee member Christopher Bailey arranged with Simon Toomer, Director  of Westonbirt Arboretum for an enlightening promenade on a fine spring day around the Old Arboretum and other parts of the bluebell strewn grounds where many of the trees and shrubs were in full bloom.

Original plantings began with the work of Robert Holford who had an interest in trees and art and design. Plantings were aesthetic and pleasing to the eye rather than simply a living catalogue of types.

The early trees were a plantation of oaks, pines and yews into which exotic species were added. Pre-arboretum landscapes can be detected with old oaks on mounds or hedgegrow lines. The Americas and China were being explored by naturalists and speciments sent back to Great Britain.

Simon pointed out that this first phase of planting has meant that many trees were more or less the same  generation and so as they reach the elder part of their lives replacement is important. If this was not being done many trees would be lost at the same time.

Research at Westonbirt is developing with possibly opportunties for new biologists to study the trees and the information available on them. Apparently Boris Johnson, London's Mayor has called on the arboretum's knowledge to decide on the next planting of trees in the capital.

Geographical Information Systems mean that each plant is precisely located. They can be monitored as they grow and this includes watching out for the types that may be be future pests. Amongst the important and well-known plants are the Rhododendrons. The Holfords liked these and collected many hybrids. Reproduction of these is now being done through air-layering.

As the group walked round Simon pointed out that the ambience of the formal area remains that of a carriage drive where in the imagination one can see the Holfords pointing out their best plants to intrigued visitors.One feature are the plants named after the sponsor of the naturalist who discovered them. For example Rhododendron williamsianum.

Some of the specimens pointed out are mentioned below.

• Eucomia ulmoides. Dull in appearance this plant produces rubber like secretions.
• Aristolochia mandshuriensis. The Birthwort.
• Pinus lambertiana. The uncommon Sugar Pine.
• Acer acuminatum. The Rat Tail maple-with a leaf end like a tail.
• Pseudotsuga menziesii. The Douglas Fire which was discovered by Archibald Menzies but David Douglas introduced it to Britain.( Note that the tree was known to local people before Menzies!)
• Acer carpinifolium. The Hornbeam Maple with leaves like Hornbeam though actually a maple.
• Catalpa bignoides. The Indian Bean Tree which was just flowering when we there.
• Wollemia nobilis. Australian araucarian found by David Noble whose wife studied at Westonbirt School.
• Davidia involucrate. Nicely shown "white 'kerchiefs".

Report on a Dawn Chorus walk by the Western Branch of the Society of Biology

Date of event: Sunday 18th April 2010   Time  0600-0800 hours

Fifteen members of the society watched the sun rise over the Bristol Downs as they enjoyed a field meeting to look at the avifauna of the area. Richard Bland, an expert ornithologist and Mandy Leivers of the  Avon Gorge and  Downs Wildlife Project ( www.avongorge.org.uk)  took the group round key sites on the Downs.

Richard pointed out that a trained ear for birdsong was essential because many birds were very difficult to see. He explained that birdsong was one part of several of the bird’s perception that differed from humans. Birds spoke much faster than humans and only if song is slowed down can many of the important micro-features be identified. Birds can also see in the ultra-violet and locate food and other objects too small for most people to see.

Despite this he described how some birds had found humans useful. A population of Blackcaps had adapted to over-wintering due in part is seems to feeding by people. Christmas pudding was one of the things they appear to have enjoyed. Whether there are separate groups of Tesco and Marks and Spencer pudding loving Blackcaps remains a future research project.

The morning of the field walk was a cold though sunny one with a clear blue sky. Only birds were flying because it was during the period of the Icelandic volcano eruption when aircraft were grounded. The cold had been more pronounced earlier in the year and Richard said that flowering of plants was certainly much later. In fact this had been a very interesting year to compare with a number of years when everyone was commenting on how soon plants were flowering.

Another floral feature noted on the walk was the growth of elm suckers from the stumps of trees lost from the landscape. Huntingdon Elms were a major feature on Ladies Miles, a road across the Downs. These were all lost though on some parts of the Downs new growth does spring up. Human perception of the Elm loss was a small part of a longer term cycle and Richard explained how we could not see the real picture. It appears humans are too slow to appreciate birdsong and too short-lived to appreciate trees!

As the group crossed the Downs the Avon Gorge was reached. Botanically very rich the gorge cliffs are home to Peregrines and Ravens. Peregrines often hunt Woodpigeons and Feral Pigeons and store them in larders in fissures in the rock face. The ravens have learnt to raid the larders and steal the cache.

The Jay has a similar habit to the Peregrine insofar as it hides acorns in the soil around the Downs. This has led to a proliferation of Holm Oak because acorns of native oaks have become less available due to gall wasps. Holm Oak has spread on the gorge slopes.  The Project is working to control the Holm Oak because it is invasive and threatens to shade out the unique flora of the area.

After seeing the Peregrine Watch team set up for the day the party retired to the Zoo for breakfast at the café. 

The following list of birds was seen on the walk. The list was kindly compiled by Richard Bland.

Blackbird
Blackcap           
Blue Tit
Carrion Crow              
Chaffinch
Chiffchaff          
Coal Tit
Cormorant              
Dunnock            
Great Tit 
Great Spotted Woodpecker
Greenfinch
Jackdaw
Jay                      
Kestrel
Long-tailed tit                                  
Magpie
Mallard                                             
Mistle Thrush
Robin                                                
Song Thrush
Swallow                                            
Woodpigeon
Wren

Report on the Society of Biology (Western Branch and Wessex Branch) visit to Blagdon Pumping Station and Lake.

Date of event: Saturday 8th May 2010.

Members of the society visited the important Bristol Water pumping station and surrounding estate to see what is needed to provide safe drinking water to hundreds of thousands of people. Jeremy Williams of Bristol Water introduced the pumping station. An original steam driven pump is conserved and can be run under electric power. A second pump is awaiting restoration funds. Originally these pumps and other pumps now removed plus the creation of Blagdon Lake were part of the provision of fresh safe water to Bristol and the surrounding area. This was and remains a significant piece of mechanical and biological engineering.

The water company has preserved the pumps and much historical material such as wooden pipe lengths of elm, tools used in the management of the estate and company records. The estate has been kept free of artificial chemicals and grazing animals to enhance water quality. This has favoured the site as a nature reserve and although public access is allowed in some parts there is strict control.

Chris Klee who managed conservation aspects of the estate for the company took the group on a walk around the site. Fish are reared in ponds outside the pumping station and go to stock the lake. These ponds lie in front of the face of the 1890’s retaining wall holding the lake.  The company has recently installed new paddle aeration equipment. After looking at the fish ponds the group looked at the grasslands in the pumping station precinct which are full of wild flowers including Green Winged Orchids. Apart from some amenity mowing the meadow is left until a hay cut is taken.

At a nearby woodland site next to the lake itself various nesting boxes were pointed out. These have been successful for Noctule Bats and Owl species although Chris pointed out that more common species such as Mallards were not above “renting” the properties.

The tree species around the lake apparently were chosen originally to try and invoke the feeling of Scotland and so Scots Pine were strongly favoured. The trees are managed with thinning from time to time.  The lake surrounds are a variety of woodland, meadow and wetland plants. Chris pointed out groups of the Adder’s Tongue Fern in the meadow area by the lake. The lake rises and falls with use and to mitigate some of the effects of this on wildlife channels and ponds provide a diverse edge to the lake.

Owl pellets collected by Chris reveal that the current management appears successful in encouraging small mammals. Examination by Roger Symes picked out various skulls and jaw bones of  field voles.  Amongst the small mammals known on the site though not identified in the trawl of the pellets are Harvest Mice.

Another species from a different kingdom was the Morel mushroom. These occur now and then and we had missed the best of the one we saw on this visit. It was interesting though to see the remains of the unusually shaped cap.

At a bird hide by the lake it was possible to have an excellent view of the lake. The area is an SSSI for the water birds although at this time of year numbers are now low. Nearby was an owl nest box in use so we could not approach too close. It seemed to be an ideal location set in the middle of a meadow next to a lake and woodland.

At the end of the visit Dr. Gerald Coles invited members back for tea and further discussions.