Sunday, 3 September 2017

Harp Trapping Wimbledon Park

Photos Dr. D. Dawson.
Note the 'harp' strings
London Bat Group was invited to take part in the National Nathusius Project in early 2016. Four 3-bank harp traps and lures were purchased in May 2016 and licences and training events were organised.

Trapping surveys occur between May and end of October with a pause in surveys between mid-June and mid-Late July to avoid trapping heavily pregnant females or bats with suckling young. Surveys commence in late May 2016 through to early October. 

Sites near water bodies are chosen as prime foraging habitat, where bats will travel to from offsite locations to spend a substantial part of the early evening. Several sites in Kingston, Richmond and Merton have been covered accruing some interesting data.

Weighing the animal + bag

Last night, five participants attended a harp trapping session at Wimbledon Park. Two traps were positioned at the lake at locations 150m apart, as part of the National Nathusius' pipistrelle project. 

We caught four soprano pipistrelle bats, one common pipistrelle and a juvenile Daubentons's bat. The Nathusius' pipistrelle eluded us, arriving later in the evening and remaining >10m from the bank side. A lure playing a loop of the  call of this species was insufficient to tempt it's investigation.

Animals fly into the 'harp' strings and fall into the white bag where they are collected at regular intervals.

Soprano wing pattern
Soprano pipistrelle bat
 They are placed into smaller bags and identified to species.

Information on the sex, breeding condition, weight, forearm and 5th finger measurements are taken during the processing of any Nathusius’ pipistrelle captured.

As a identification validation the cell structure of the wing patterns - or veination - is checked. Hair samples can be taken for isotope analysis which should reveal more insight into where the bat has travelled from. As the project has advanced the animals are more likely to be ringed.

So far >141 Nathusius' pipistrelle bats have been caught  and 100 ringed. This August 25 Nathusius' pipistrelle were caught of which one was a recap from Surrey Bat Group (Molesey Reservoir to Kempton Park Nature Reserve - 1.7km) and another a London recap (Walthamstow to Woodberry Wetlands - 2.8km).

In addition, three bats have been controlled wearing rings that are registered in Latvia giving us valuable information about the movements of this animal.Last week a bat that was ringed in Latvia was controlled at Kempton Park.

Table: To show the number of passes per bat species  at Wimbledon Park 2.9.17 (M. Wagstaffe).

Noctule bat 16 2.5%
Leisler's bat 2 0.3%
Serotine bat 1 0.2%
Common pipistrelle bat 145 22.7%
Soprano pipistelle bat 425 66.5%
Nathusius's pipistrelle 21 3.3%
Daubenton's bat 29 4.5%
Total 639 100.0%                 

Monday, 28 August 2017

New bat species recorded for Kingston!

What bat is that (photo, M. Wagstaffe).
Five bat species were caught at a Chessington location, during a harp-trapping session, convened by members of local Bat Groups as part of the National Nathusius' pipistrelle project. 

This included several common and soprano pipistrelle bats; two Daubenton's bats; a brown long-eared bat and another that took observers a little time to identify.


By looking at the dentition under a magnifier it was possible to see which of the small Myotis bats matched  the cusps and protocones present or absent on the teeth. It turned out to be a whiskered bat; there are no recent records for this species in the borough.

This is because the genus is difficult to record on bat detection equipment, emerging slightly later than pipistrelle bats and as a woodland specialist has specific habitat requirements.

At a similar trapping session at Kempton Park, a whiskered bat was caught in the harp-trap which was a first for Hounslow. A Nathusius' pipistrelle was controlled that had originally been ringed in Latvia, indicating the value of the project in illuminating the long migration routes taken by these small mammals.

Whiskered bat

Friday, 25 August 2017

Mammals of Kingston: Mink along the Thames and Hogsmill rivers.

Mink are seen dispersing at this time of year.  The River Mole is unfortunately a reservoir for this species from where they move up the Thames and onto the Hogsmill.

Mink are known to be breeding in the borough, possibly at more than one location. It is regularly seen swimming around Raven’s Ait, usually at dusk. They have been  seen under the bridge at Charter Quay since its construction.

Rivers must be mink-free for two years before translocation of water voles is permitted; as this species is considered a voracious predator of the water vole.

Nick with a mink skin

This is a mink skin which gives a good indication of size of the animal. Mink footprint traps have been installed along local waterways. They have a clay base in order to look for footprints which are indicative of their presence.

There have been a number of sightings recently some of along the Hogsmill and Thames:

  • The path at Hogsmill O.S. is being improved by the Lower Moles and two of the volunteers saw a mink in the Hogsmill close to the A3.
  • I saw Martin B. this afternoon who mentioned seeing a mink  along the Portsmouth Road  (close to a breeding site) this morning at 11a.m. The animal moved without paying any regard to  pedestrians along the river.
  • Last week a mink was recorded as a 'small otter' at the Clattern Bridge by a member of the public.
Although there are no verified sightings of otters  along the River Thames (recent anecdotal records usually pertain to harbour seals or mink) there have been sightings at the margins along the ‘out of borough’ tributaries. For this reason, sightings are dependent on survey effort and an Otter Bridge Blitz resurvey of the National Otter Survey 2009-10 took place along the river Mole and Wey (5.4.14). 

There is a system by which records are validated when reporting animals. In birds this is especially rigorous as a description is required. With mammals it is useful to use the mammal society recording form recording form or the Kent Mammal Group have a sophisticated mammal records scheme see here record forms

If you want to read more about the Mammals of Kingston see a write up here: Mammals-of-Kingston-upon-Thames-A. FURE 2017.pdf If you want to read more about the local mink population -:search 'Mink' in the box at the top left hand side.

Wednesday, 2 August 2017

Beaky Bat

This is a young male common pipistrelle bat, which was found on the end of someone's shoe in Surbiton. He is called 'Beaky'. In naming a bat, some of us follow a convention of using the road name where they were found - in this case Beaconsfield Road - to  remember the return location. Over years of bat care, naming assists in reminding us of those  difficult injuries, strange locations, and any sympathetic vets we may have found along the way.

Beaky at the top of the flight cage
Beaky only weighed 3g on arrival and was  fed small amounts of mini-mealworms four times daily. He was soon self-feeding, and within ten days had doubled his body weight spending his time sitting in his food dish. 

Unfortunately his wings were stiff and he has never flown. He will do press-ups and wing stretches but not fly. He crawls to the top of his practice flight tent and goes to sleep. He has gone on holiday to Demian's house so that he can have some flight therapy.

Sunday, 16 July 2017

Oil drilling and fracking in the Surrey Hills

'Having been harrassd by too much thinking and too many trivial engagements, and an employment that I shall never like, I determined that I would respire one mouthfull of real country air if possible and I know at the same time that pollution of smoke reaches ten miles round the Metropolis. I had heard much of Leithe Hills and of Box Hill in the neighbourhood of Dorking. . . . Remember that I am no Welshman, therefore to me these Hills are Cader Idris's and Snowdens.— (The Letters of Robert Bloomfield: to George Bloomfield, 17 April 1803)'.

John Clare's Swaddywell  Landyke Trust

So I wonder what his friend and defender of the environment, John Clare, would have made of the current plans for oil drilling at Leith Hill; that threaten archeological and wildlife features alike. Some of the ancient droves and sunken lanes will be destroyed by vehicular movements and current wisdom suggests that oil drilling carries the same risk of water contamination as does fracking. It is a paradym shift in the way we now view the environment and its dwindling resources.

John Clare had absolute clarity on the roots and impacts of privatisation on our natural heritage, as common land disappeared under the Enclosure Acts, leaving rural folk alienated and forced into penury. Two lost springs in Helpston village were described thus:

vile enclosure rifld thine
mine in manhoods trouble fell
I sympathise thy  fate wi mine
I love thee passing well

He also incredulously recorded: ..."avarice is never conquored, such is the cunning of avarice [that] like the tricks of a conjuror [it] defies detection."

Friends and colleagues are so incredulous that this could even happen - far too much to compute- the import is passing them by. For them the links are here:

The Surrey Hills sits on the fifth largest oil field in the UK and prospective drilling tests are set to begin this year. There may be an oil rig on top of  Leith Hill in the near future.

Specifically, the area or and around Leith Hill is where Europa Oil & Gas (in conjunction with the UK government) are interested in extracting an estimated five million barrels’ of oil under the hills.

Europa Oil & Gas will apparently be attempting to horizontally drill using a rig that passes under Coldharbour Village. This on its own will entail cutting down a hectare of trees and constructing a lofty and highly visible drilling rig.
The Surrey Hills has a degree of protection because it is an Area of Outstanding Natural Beauty but the slide down the slippery slope has started. Local campaigners have set up a protest group on Facebook

Tuesday, 11 July 2017

King Athelstan Recreation Ground: 11 cubic metres

There are a number of routes by which council decisions are made. Officers make decisions, hopefully based on the greater good. Councillors are lobbied by residents, which can lead to powerful but not necessarily good results. In past years, several London boroughs have requested  that I undertake bat surveys at the council's expense; perhaps because one member of the public has commented that an area is too dark at night and additional lighting should be installed.

The council then look at the survey results and recommendations,  weigh them against their current policies as well as legislation pertaining to biodiversity and priority species; and make a decision that the case has or has not been proven. 

I am not sure what processes have lead to the decision regarding the new vehicular and pedestrian route around the perimeter of  King Athelstan recreation ground along Villiers Road; but they do not seem to be matched against any of the policies.

Neither do they recognise the councils documents on Strategic Flood Risk Assessment; exacerbated flood risk as demonstrated by the Environment Agencies Flood Map (which shows that this is in the highest risk area for flooding, see below), British Standard: Trees in Relation to Design, Demolition and Construction BS5837: 2012 pertaining to heavy vehicles on the root plates of trees and the root protection zone, the desirability of permeable surfaces, the needs of biodiversity, the urban heat island effect etc. etc.

What is more confusing is that there are ten operatives working for Cappagh; on this project for  two  weeks so far, complete with two caravans and heavy plant (but no tree protection). This is a massive investment, requiring ongoing maintenance.

uncapped syringes
By contrast take a look at the nearby public footpath along Hogsmill Lane, where the riverbank is completely overgrown, strewn with litter encouraging drug use and consequent syringes.


see also posts: -urbanisation-and-loss-of verges in the borough and rainscapes-in-lb-enfield

Ironically, a development proposal for a site almost opposite the recreation ground, at 40 Villiers Road, was subject to a planning appeal APP/Z5630/W/16/3165508 (May 2017). The planning inspector did not like the loss of 11 cubic metres from the storage capacity of the floodplain. He said,

'Detailed information has not been provided in terms of how the development would compensate for the 11 cubic metres loss in floodplain storage. Consequently, I do not have adequate information to demonstrate that the proposal would not increase flood risk off site through a loss of flood storage. Finally, I do not consider that in flood risk terms the application has been the subject of a robust sequential test.

Hence, I cannot be certain that it would not be possible for the development to be located in an area with a lower probability of flooding. For the above reasons, I conclude that I do not have enough information to demonstrate that the proposal would not give rise to unacceptable flood risks. Therefore, the development would not accord with the flood risk aims of the National Planning Policy Framework, the National Planning Practice Guidance, Policy DM4 of the CS and Policy 5.12 of the London Plan 2016.