Tuesday, 10 October 2017

Earthwatch Water Blitz

Nitrates 10 and Phosphates 0.5
Low water at Middle Mill
The second Water Blitz of the year - coordinated by EarthWatch - was undertaken during 2.10.17, at locations along the Hogsmill river similar  to those of the May Blitz. Starting with Knights Park TQ18536872, the nitrate level was high - scoring 10 in the sample tubes from the kits that are issued to us. All sites went on to score 10 for nitrates unless otherwise stated.

Hogsmill SW outfall
Just below the outfall at the Hogsmill Sewage Works TQ19156857, phosphate levels were the lowest of the survey at 0.1. Is this the result of phosphate stripping? The highest phosphate level was achieved at the Channel of Cess (CoC), the small stream entering the Hogsmill at TQ19866831.


Sewage fungus
In addition to the highest (therefore the worst of the chemical readings) there was a strong odour, milky colouration, sewage fungus and fresh rag lined the channel. This type of chronic pollution can be  reported to the Environment Agency on 0800807060 and is given a reference number in this case NIRS 01559048.

Tomato plant in a culvert
As we walked upstream towards another pollution hotspot at Green Lane Recreation Ground TQ20056788, a tomato plant was seen growing out of a culvert. Tomatoes and figs often indicate the presence of sewage as tomatoe seeds pass intact through the gut. Phosphates scored 0.2-0.5

new habitat creation
sewage at the outfall
Despite all the instream habitat improvements at the A240 Tolworth -see previous posts- the is still an unhealthy outfall and an amount of sewage fungus around its environs. True to form the scores equalled the CoC.

Currently, there are over 1800 data points collected across the Thames Catchment undertaken with volunteer effort. A new mapping application allows you to visualise, analyse and download all the data collected during the different WaterBlitz .

The map can be access through the Freshwater Links here:


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.