Showing posts from June, 2012

Daubenton's Bat Maternity Colony

Over the past 8 years, the London Bat Group Batty Boat Trip has provided time series data, of the bat activity along stretches of the river at Hampton Wick, Kingston, Surbiton and Thames Ditton (see Bat Pages for a species list, right hand tabs). It is one of the annual monitoring visits studying the bats at the Seething Wells Filter Beds. This year there has been concern at the change in activity at the site. We failed to see any Daubenton's bats during their emergence period. A subsequent visit in perfect weather conditions ( 8/8 cloud cover, 16 degrees, no wind,17.6.12) noted that animal numbers and the pattern of activity has changed significantly. Animal numbers are reduced and the bats had no urgency to emerge as per adults with young to feed. The light sampling behaviour normally observed, was not apparent to the same degree as in previous years.
When bats have young, the adults need to forage close-by, as they must return to feed their pups (milk). When the weather is b…

Plants of Seething Wells

3 species of scabious are known to grow here. Field scabious was a common perennial of (usually calcareous) waysides, meadows and downland. It is widely distributed over the whole of the F.B's and can be seen from the south western part of the wharf , to the boundary fence at Hart's Boatyard. It is the only site in the borough where this plant is found and this group is rare in London.
Common knapweed is found at several sites in the borough such as Tolworth Court Farm, Chessington, New Malden along with a small patch at Kingston Cemetery (where its spread  has been encouraged by a relaxed mowing regime). It is a plant prevalent in neighbouring Richmond, which has preserved its unimproved grassland sites.

This month the F.B's exploded into colour and the mass of yellow is a mixture of bird's-foot trefoil and hop trefoil. These are essential for butterflies and other insects. They also grow along the  grass bank at Thames Ditton Marina and take a quick look at the rais…

Seething Wells: Current Water Levels

Yesterday Thames Water lifted the hosepipe ban after unprecedented rainfall in our region. Despite the notice on the fence, it doesn't appear to have rained at Seething Wells since last October, when the Filter Beds were pumped out (the second  time in a year) to  'inspect  the structures'. Despite the rain, water levels have not increased an inch.

These inspections, led to large piles of substrate being piled at the foot of each slope (many now vegetated)  and have served to keep the F.B.'s permanently drained, preventing the breeding of any little grebes this year. This will surely invalidate the 2012 bat surveys as the habitat will be sub-optimal and not support foraging Daubenton's bats who need uncluttered open water over which to trawl for insect prey.

Seething Wells: Spanish Broom

The Spanish broom Spartium junceum is a common Mediterranean shrub widely planted on roadside banks and naturalised in the south of England. This bank of broom was planted by Thames Water over 50 years ago and since then has provided this stunning show every June. Last week the tops were starting to flower and this week it is in full, brilliant glory.  In its native Spain it is uses as a source of fibre for making paper and cloth. In France it is the constituent of an essential oil known as Genet Absolute where it has been grown in the south France (and Spain) since the 16th Century as a perfume ingredient. The Plantagenets named themselves after this plant (planta genet).
The leaves are of little importance to the plant, with much of the photosynthesis occurring in the green shoots (a water-conserving strategy in a dry climate). The leaves fall away in late spring and summer shoots are covered in profuse fragrant yellow flowers 1 to 2 centimetres across. In late summer, the seed pod…

Flowering now: Hoary Cress

The white flowered umbels of this pepperwort at the entrance to the wharf at Seething Wells are that of hoary cress, Lepidium draba (aka Cardaria draba) and also known as Thanet cress, which is a deep-rooted, perennial mustard. This plant is becoming increasingly common on waste ground, roadsides and field borders in England and Wales. It arrived in this country from Europe at Thanet in Kent and was first recorded after the Napoleonic Wars. Sick soldiers were bought to Ramsgate on mattresses stuffed with hay, later given to a Thanet Farmer, who ploughed them into his fields as manure. The cress appeared in great quantity spreading over the south coast and via wharf sites. It is prevalent in East London wherever ‘sailors shook out their mattresses’. Plants are a frequent link to our trading past and this is a fine example. In our borough the plant is recorded at Elmbridge Meadows, Holy Cross School, Hogsmill Sewage Works and along the wall of Kingston Cemetery. I used to feel  sad whe…