Sunday, 21 May 2017

Centenary Walk Richmond Park, Kingston Hill and Wimbledon Common

Elizabeth finds Crassula
Government noise monitor
Led by members of the London Geodiversity Partnership and supported by the Friends of Richmond Park and the London Natural History Society, 35 of us celebrated one hundred years since the original GA excursion 19.5.1917. We started at Gallows pond, a large landslip near Thatched Cottage House, where there are now two ponds on the springline; one was filled in due the appearance of an invasive species Crassula helmsii aka New Zealand pigmyweed. Unfortunately it appears to be back. The new masts appearing around the park are monitoring  noise and pollution from Heathrow.

Claygate beds
 Cynipid wasp, Neuroterus quercusbaccarumtion
While members of the GP demonstrated the plasticity of the  London clay,  terrace gravels, 'bunter' pebbles (transported by tributaries from the north) veined quatz, and lower greensand churt (used as a building stone near Guildford); members of the LNHS demonstrated currant galls seen here on the catkins of Turkey oak (see photo).

Gravel extraction took place in Richmond Park either from quarries or from naturally arrived gravel at Pen Ponds. Clay was also extracted for brick making.

Before crossing to the Coombe Golf Course at Warren Road and the university site at Kingston Hill, we discussed the hand made bricks found within the eight mile wall around Richmond Park. They were made using the local clay  by itinerant brick-making families in the 1650's.

Caesar's well
Mick drinking from the spring

In  the afternoon we crossed the A3 and the Beverley Brook to walk up to Wimbledon Common. Here we are looking at Caesar's well, later visiting the Queens Mere before reaching the windmill.

 En route we had an opportunity to discuss the various granites we had seen (around the well) and their provenance. At the excellent Windmill Museum there is a history of windmills and we noted the materials used for mill stones including the expensive and highly prized French quartz.

Mr Daubenton

Louis-Jean-Marie Daubenton (May 29, 1716 - December 31, 1799) was a French naturalist who gave his name to Daubenton's bat Myotis daubentoni


Friday, 28 April 2017

Swifts are in

Swifts are among the last summer migrants to arrive and around the first to leave our shores. Some birds were recorded over Island Barn and Staines Reservoir last week, and my records show that this is the week when they usually arrive in Kingston and are found feeding over Pen Ponds.

Breeding still takes place in Berrylands (14) with young fledging around the first week of August. Peak numbers are recorded from birds breeding at Bushy Park, Hogsmill Sewage Works, R. Thames, and Sunny Surbiton with the favoured deep eaves that characterise properties in and around Maple Road.

Swifts  spend most of their life on the wing, including sleeping and mating. There are useful facts on swift biology here; although I find this website the more pertinent for the airing of issues surrounding the perilous decline of this bird

Between 1995and 2011 we lost about a third of the birds that nest in Britain. A major reason for this was the large scale refurbishment of social housing as well as historic buildings (similar issues affect  all comensal species such as sparrows and bat species). The former niches used by these birds are never provided within new refurbishments. Replacement UVPC and plastic soffits, will never warp suffiently to provide access to warm dry crevices.

Each year sees a new initiative launched by NGO's to draw awareness to the problem. In London (c2006) there was BOB initiative (Birds on Buildings) run by the GLA. The RSPB are currently engaged in a monitoring programme and I was lucky to meet some of the participants recently on a recent holiday.

Swift and Bat Box  Slovakia
The Slovakian Bat Conservation Group per Martin Celuch were ahead of the game - producing a joint bat and swift box - for two of the species most threatened from our desire to keep our dwellings visitor free. These boxes can be erected on the flank walls of tower blocks, which have proved popular, removing some  conflict with residents regarding noisy bats and unsightly bird droppings.

Migratory birds  en route to thier breeding areas  experience a suite of changing problems - that we can't mitigate - illustrating the continued need for international agreements. This includes the megahotels, located along the coastline of Greece and Turkey. Six birds were found grounded limp and wet - on hotel balconies - after flying into windows after rain at Kusadisi, Turkey.

After a couple of hours in a dark drawer most birds were able to fly to their final destinations. One took slightly longer, requiring rehydration and rest, but was able to pump itself up sufficiently to catch up with the others.

Wednesday, 22 February 2017