Monday, 17 October 2011

Seething Wells: Bats


Kingston benefits from being encapsulated by RB Richmond and the river Thames. Kingston is 12% open space, whilst Richmond is 55% open space. The nature reserves in Kingston tend to be small linear parks along the rivers Hogsmill, Bonesgate and Tolworth brook. Woodland canopy cover is rare habitat in Kingston and tends to be restricted to Chessington and Kingston Vale. It is woodland that forms the primary habitat for many bat species all of which will usually spend some of their nights foraging near water. Bats require large areas of quality habitat, with strong linear features used for navigation and that are unaffected by light pollution. There are 17 bat species in the UK. Of these 10 are regularly recorded in the London Region, all of which are recorded in Richmond Borough (although two of these are only rarely found). Of the eight species recorded in Kingston: four are recorded regularly (emboldened in the table below) one occasionally; and 3 rarely. All have been recorded at Seething Wells Filter Beds and the adjacent river (Batty Boat Trips 2006-11). No other site in the borough can claim such bat interest although Canbury Gardens is close second for the numbers and abundance of bat species.
Table 1: Species and Status of bats recorded in Kingston upon Thames. Adapted from Mitchell-Jones (2007)  
Species 
Frequency and most probable roost site

Common pipistrelle
Common: Mainly uses buildings as roost sites. Winter roosting at Seething Wells. The commonest pipistrelle species recorded foraging at Seething Wells. Roosts at Kingston Hill (several small roosts known).
Soprano pipistrelle
Common: Can use trees and buildings for roosting. A very large roost known in Surbiton. Smaller roosts are also recorded in Surbiton and on Kingston Hill near Richmond Park.
Nathusius’s pipistrelle
Has been a speciality of Kingston in former years. Recorded along the river especially the entrance to Canbury Gardens, Railway bridge and at Seething Wells since 2001 and usually during the June Batty Boat trip, but not recorded this year for the first time.
Long–eared bat
Common in wooded counties but there are a few strongholds in some larger parks where there are historic building. Very rarely recorded in Kingston.  Not recently   recorded at Seething Wells.
Serotine
Local and very rarely recorded in Kingston in recent years, roosts in buildings, not recorded at Seething Wells since 2006. 
Noctule bat

Uncommon (TMJ) (Briggs et al, 2008) .Roosting nearby but no roosts known in the borough. Forage over the Filter Beds, amazing displays over the Filter Beds during this years Batty Boat Trip
Leisler’s bat
Rare nationally. Roosting nearby and forage over the Filter Beds
Natterer’s bat
Common in wooded counties rare in Kingston. Recorded at the Fishponds, Chessington and Seething Wells but not for several years
Daubenton’s bat
May be declining in the London region (Briggs et al, 2007)Roost on site at several locations. This bat uses trees in Bushey Park, buildings or structures over waterLike most bats can use structures (or trees) as transient, mating, hibernation or summer roosts.



PIPISTRELLE SPECIES:

 Three pipistrelle species (common, soprano and Nathusius) have been recorded during surveys in and around Seething Wells. The “common” pipistrelle has been split into two separate species Pipistrellus pipistrellus that echolocates around 45 kHz and P. pygmaeus that calls around 55 kHz. The 45 kHz pipistrelle can use a wide range of habitats, but frequents the more open situations, such as woodland edges, parkland, recent plantations, watersides and gardens. Colonies, usually of 30-60 bats; they frequently use buildings for roost sites and have roosted in the small pumping station. The 55 kHz pipistrelle may prefer waterside locations such as rivers, lakes and wet woodland. Colonies are usually larger than the 45 kHz pipistrelle with numbers often in the region of 100-150. Roosts in houses are frequent but tree roosts are also found. Nathusius pipistrelle was first recorded along Barge Walk during 2001 (whilst watching Daubenton’s bats emerge from the Filter Beds site). Since then, this species has been regularly recorded during annual Batty Boat Trips and the ‘Daubenton’s Waterway surveys’ until this year, when it failed to make its regular appearance. As a specialist of open water habitats it does not remain as close to vegetation as the other pipistrelle species and is often found at reservoir sites around London. For this reason we have been recording Nathusius around Seething Wells during the last ten years.
  
NYCTALUS BATS: Leisler’s and Noctules
Noctule bats are one of Britain’s largest species, they are adapted to fast flying above the treetops and can cover large distances from roost to feeding areas, 10km or more being frequent. Noctules normally feed on larger beetles and moths but will take much smaller prey such as chironomids when these occur in large swarms. Noctule roosts are almost invariably in hollow trees, woodpecker holes being a favourite site and the last 5 years they have roosted very close to Seething Wells. They are becoming increasingly rare and there are pockets in London which remain a stronghold for them. A car survey undertaken by the Hertfordshire & Middlesex Bat Group found only 9 noctules after driving 600 miles (2005).  The status of Leisler’s bats is under re-evaluation due to recording analysis highlighting their regular confusion with noctule bats. Observations at London sites suggest replacement by the closely related Leisler’s bat at some former strongholds. The appearance of Leisler’s over the Filter Beds varies from year to year and sometimes it is only recorded briefly.

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