Bats in the borough
Due to the influence of the Thames there are several large soprano pipistrelle roosts in the borough. A maternity roost in a cavity wall in a Twickenham residence numbered 160 bats. Generally these bats will move once their young become independent. Bats and the weather |
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| © John Inglis 2005 |
There are signs that our local bat population had a rough time during the wet June weather. We have had many grounded bats from Kew, Twickenham and Richmond. Titchmarsh from Kew has a broken wing which should repair over time. Some babies appear to have been abandoned or have fallen out of their roosts. Three babies have been collected from a roost near the wall of Richmond Park and are being looked after. The best carer for a baby bat is its mother as they are very difficult to hand feed although at present all three seem to be doing well.
Bats and Lighting
Meetings have taken place to try and replace the lighting along parts of the river in Twickenham. Ideally there should be no light spillage onto the water where bats are feeding. Light monitoring at intervals along this location shows that there are many different sources of light pollution, which are often brighter than some bat species will tolerate. Rivers are designated corridors for wildlife but then this designation is not managed in any way. Rivers should be maintained as dark corridors to be suitable for wildlife movement. User surveys are being undertaken this year to see how many people use the towpath at night and whether lighting could be reduced.
Batty Boat Trips
In 2006, we ran Boat trips monitoring the bats between the Thames Ditton Islands as far as Rainham. There were so many bats along some of the Thames reaches that we ran a pilot boat trip last August to show members of Thames-related organisations the importance of the river as a dark corridor for bats. On board we had members of the Thames Landscape Strategy, Local Authority Planning and Tree Officers, members of English Nature and the Environment Agency.
This year we ran the Thames boat trip in June 2007 and were delighted that our MP and the Deputy Mayor for Kingston could attend. Although it was a late night (as it was approaching midsummer) it is the only time of year we get excellent displays of noctule bats. Last June we had over 150 passes of this species which made visually impressive sorties over our boat as they foraged for beetles.
We are currently monitoring the Regent's Canal as it passes through north London as it is a good method of obtaining data, particularly on Daubenton's bat, which is a species we are concerned about in the London Region. This bat may be affected by the increase in light pollution as we increasingly develop canal and riversides. Get in touch if you want to book a place on a boat trip by telephoning 020 8974 6670 or look for details on the London Bat Group website.
Hampton Court Park Bat Walk
As part of the Hampton Court Open Weekend this May, an evening bat walk was undertaken in the park with twenty members of the public who were treated to a rare peak inside the ice house. We waited patiently for bats to emerge after sunset and, just as were about to give up hope, a stream of noctule bats appeared. Three foraged over the park grassland while the rest flew towards the river Thames.
Richmond Park Winter Bat Surveys 2006
Richmond Park, Isabella Plantation 19 April 2006
Three of us entered the Isabella Plantation at sunset to the usual calls of tawny owls (8pm, temperature averaging 13 degrees). Flowering plants were a spectacular sight and the large yellow arum-like skunk cabbage lining the brook, gave an impression of a far more exotic location. The abundance of these spring flowering shrubs should be an indicator of good insect availability for bats. We spread out and took recordings of bats encountered. The activity was less concentrated than that of our winter visit but we still had passes of 5/6 species. This time brown long eared were not in evidence but we did record a Leisler’s. At the Ham Gate exit at 9.45pm, a Daubenton's bat was seen feeding over the pond. This makes a total of 7 species recorded in the Isabella:
- Pipistrelle pygmaeus
(most commonly encountered species and most likely roosting in the plantation) - Common Pipistrelle
- Brown long-eared
- Daubenton's
- Natterer’s
- Myotis unidentified species
- Leisler's bat
- Serotine
Richmond Park, Isabella Plantation 15 February 2006
Two of us entered the sheltered environment within the Isabella Plantation at sunset (17.16pm). The plantation has a number of winter-flowering trees and plants such as lots of Hamamelis. This is a type of witch hazel probably H. x intermedia ‘Pallida’, which has sulphur yellow blooms that glow in winter light. The 5/8” long flowers are yellow and fragrant, borne in clusters along the stem of these small trees and curl up in cold weather. Heathers are also in flower and the Isabella is generously planted with them. All these are attractive to insects including large night flying moths, which in turn, are important prey items for bats.
We encountered five or six species of bat enjoying a brief respite from the winter weather. Two pipistrelle species were the first to emerge at around 5 minutes past six. Brown long-eared bats were flying low around the bushes, chasing large moths, one of which flew painfully into my eye. Several Natterer’s were encountered and one serotine. We had to leave the park by 8pm as the deer cull was taking place. No further bats were encountered on our exit, neither in the park, nor the pond on Ham Common. It is likely that by now bats had returned to their roosts, as at this time of year emergence does not normally last very long.
