Book those bats! (2nd September 2011)

Book those bats! (2nd September 2011)

Pipistrelles – Creekside to Sutcliffe Park

Night Sight
Illusive creatures, bats. As night specialists, they’re difficult or downright impossible to see. But using electronic detectors we can now identify individual species – and get an idea of their numbers.

No excuse then for not recording these extraordinary mammals along the Quaggy and below its confluence with the Ravensbourne. By doing so, we can press for measures to protect them and promote their welfare.

The common pipistrelle (Pipistrellus pipistrellus)

The common pipistrelle (Pipistrellus pipistrellus)

Though a tiny bat, its wingspan can extend to 25 cm (10 inches).

It’s not easy counting bats even with a detector. In urban areas you have private properties which can screen the river, and most park gates are routinely locked at night. But a general picture can be gained. And this year our record of bats along the Quaggy is in line with what we found in 2010.

Common pipistrelles (CPs) and occasional soprano pipistrelles (SPs) have been found all along the river from Deptford Creek to Sutcliffe Park – often in the most unlikely places.

Geek alert!
If you’re a Chris Packham ‘Springwatch’ type geek or just interested in what we have found on your stretch of the river, see below:

Ha’penny Hatch Bridge, Creekside, Deptford
2nd April 2011, 20.50. Tide out. CPs detected on both sides of the channel. An occasional bat seen.

Broadway Fields, Deptford, through Brookmill Park to Elverston Road
2nd April 2011, 21.10 to 21. 40.CPs detected throughout this stretch of river. Surprisingly, they are particularly active in the concrete channel just south of Deptford Broadway DLR station. The first bridge encountered makes a fine detecting and viewing platform as the bats flit below. Continuous chatter from detector and 3 common pipistrelles seen at one time. The next bridge going south, (it leads to the Stephen Lawrence centre) also proves a good spot though viewing is restricted downstream. CP activity apparent all the way along the river through Brookmill Park.

River Ravensbourne (with Quaggy) at Broadway Fields, Deptford. An unlikely spot for bats, but common pipistrelles regularly visit. Nearby willows and lime trees would certainly help boost the insect population in the channel

River Ravensbourne (with Quaggy) at Broadway Fields, Deptford. An unlikely spot for bats, but common pipistrelles regularly visit. Nearby willows and lime trees would certainly help boost the insect population in the channel

Concrete Channel by Tesco’s, Lewisham town centre
2nd April c. 21.55 – 22.05. SPs detected on both sides of downstream bridge across concrete channel. Occasional CPs along the channel walking towards the upstream bridge. More SP’s detected here at least 2 seen at one time to south of the bridge where the river approaches Lewisham Station.

The river by Tesco's, Lewisham. Nature is doing its best to reclaim a sterile man-made structure. Common and soprano pipistrelles have been detected (and seen) in the immediate vicinity

The river by Tesco’s, Lewisham. Nature is doing its best to reclaim a sterile man-made structure. Common and soprano pipistrelles have been detected (and seen) in the immediate vicinity

Quaggy Gardens, Lewisham High Street
2nd April 22.15 and 12th April 22.40. No bats detected but on 24th March 21.55 at least one CP present and 17th April 21.00, 3 CPs

Clarendon Rise bridge
Not usually detected here but on 17th April around 21.00 making passes on both sides of the bridge.

Clarendon Rise to Eastdown Park
No public access for monitoring which is a shame because suveys from QWAG members’ gardens shows this stretch to be a rich hunting ground for bats, with common pipistrelles invariably patrolling.

Eastdown Park bridge
With patience, a CP usually to be detected on the downstream side but on 23rd April, c.21.35 found both sides perhaps, the same bat passing underneath.

Weardale Road
An open stretch of natural river where CPs are usually to be found. Several present on 12th April around 22.30 and again on 23rd April 21.45.

Manor Park
Occasionally the gate doesn’t get locked. It wasn’t on 23rd April c. 21 50, and CP activity was detected especially at the more open upstream end where the river enters the park.

Staplehurst Road bridge
This is the next public access point upriver from Manor Park and invariably CPs are to be found here. On 12th April c.22.15, downstream side, at least two were hawking along the three lime trees adjacent to the bridge. Bats have hardly ever been detected where the river crosses Manor Park road or on downstream side of Manor Lane bridge. So could the CP’s regular presence here be due to the small scale river restoration schemes in the immediate vicinity? As shown in the photo, waterside plants are flourishing as embankments established within the concrete channel. Plants means insects means bats!

Staplehurst Road bridge crossing the Quaggy. These small-scale restoration projects within the concrete channel doubtless produce insects for local foraging bats

Staplehurst Road bridge crossing the Quaggy. These small-scale restoration projects within the concrete channel doubtless produce insects for local foraging bats

Manor House Gardens
Entry possible via an unlocked gate on 12th April c. 21.50. CPs over the lake in the park kept the detector continuously chattering. An occasional SP, too. From the bridge in Manor Lane, it’s usual to pick up a hunting CP upriver here or along the hedge just inside the park parallel to the river.

Brightfield Road bridge
Usually a CP presence here particularly on the downstream side where the river approaches Manor House Gardens. On the 12th April c.21.30 active both sides.

Lee High Road bridge
CPs nearly always to be detected on the downstream side of the bridge by the Duke of Edinburgh pub or from its garden. At least one bat detected and seen on the 12th April c. 21.20. Rarely on the upstream side by Penfold’s salesroom.

Osborn Terrace
Invariably, a good bat detecting spot. Several CPs usually present along this natural stretch of river and the white wall of an opposite side garage means they can be seen. On the 12th April c. 21.05 at least three together. Same on 21st April, 21.00.

Osborn Terrace, Lee Green - a regular haunt for common pipistrelles. The passing bats show up against the white riverside wall

Osborn Terrace, Lee Green – a regular haunt for common pipistrelles. The passing bats show up against the white riverside wall

Weigall Road Recreation Ground
Always some CPs present along this unlit stretch of river. The case on, 21st April c.22.30. Interestingly, an ancient hedgerow running parallel to the river some 50 meters away, equally unaffected by artificial lighting, showed no bat presence on this occasion. River corridor preferred it seems. At least one CP can usually be detected downstream from the Weigall Road bridge. Rarely, the upstream side, but on the 21st April, a bat presence detected both sides.

David Lloyd Sports Centre
Surveyed 21st April 21.35 to 22.20
Permission to survey has always been granted. The grounds occupy the north bank of the Quaggy and also border the Lower Kidbrooke and its confluence with the Quaggy. Tennis courts back on to the river and are strongly illuminated at night, seemingly even when nobody is playing. The powerful lights show just how dense populations of midges can be. At least one CP tolerated the conditions here and in 2009 a tennis coach said bats would home in on the ball as it was tossed up for serving. At least two more CPs some 50 metres downstream where the intensity of the light was diminishing. Only one other CP otherwise recorded, at the furthest point downstream where a leylandii hedge marks the limits of the property. The dense tree cover on both sides of the river probably limits biodiversity.

John Roan School playing fields
Permission given to survey grounds. Footbridge here parallel with the Kidbrooke Park Road bridge had CP activity on both sides (18th April, 21.30). Since river restoration in 2004, trees and shrubs have burgeoned and a CP presence was detected walking downstream to the confluence with the Lower Kidbrooke. (Floodlights from nearby all-weather football pitch off). No bat activity along the Lower Kidbrooke stretch.

Sutcliffe Park
18th April 20.45 – 21.20. Floodlights off. As usual, several CPs active by the inlet and along the avenue of trees leading northward. CP presence also in avenue of trees on northern boundary but not the western one. They’ve yet to be recorded here which is surprising as these are mature trees and a short distance from the hedge surrounding the running track where they are to be found. As usual too, mix of CPs and SPs over the lake.

Common pipistrelle at rest. The common usually has a black face mask, unlike the soprano pipistrelle. Photo: Hugh Clark

Common pipistrelle at rest. The common usually has a black face mask, unlike the soprano pipistrelle. Photo: Hugh Clark

Skills

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8th April 2015

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