Thames Landscape Strategy - Hampton to Kew -

Intelligent Lighting

It is so good to see spring at last. The warm sunny weather is just what we need after what has proved to be quite a long and cool winter. The blue bells have suddenly burst into flower, the cherry blossom is out and all week I have spotted bats flying along the river chasing the millions of insects that thrive along the Thames.
It is also the time of year that we can start to enjoy the longer evenings now that it’s warm enough to sit outside or walk near the river watching the sun go down. If you do pop down to the Thames for a summertime evening stroll don’t be surprised if you are stopped by one of our members of staff who are currently carrying out surveys to identify the ways that people use the riverside at dusk and into the early evening. This year-long study is to inform a new project to improve the street lighting along certain lengths of the towpath.
Good lighting is so important – it can decrease crime, make us all feel safer, aid accessibility, reduce accidents and can be beautiful. The key is to get just the right amount of light, where needed and when it is needed –referred to in the business as ‘intelligent lighting’. Along the waterways this is even more important if we are to help conserve nocturnal wildlife such as birds, bats and insects. What we need is lighting that is good for people, good for the environment and good for nature. To achieve this we have to try and reduce light pollution wherever possible.
There are three types of light pollution. The first is termed ‘sky glow’ which is caused by lights being angled in the wrong way throwing light horizontally up into the sky. This is the ambient orange glow that can be seen in the night sky above towns and cities. It is such a waste of energy and has been estimated to cost the taxpayer £50m per annum in wasted electricity in the UK alone.
The second type of pollution is ‘glare’. This is light that strays from where it is needed adversely affecting our ability to undertake any given task. We are most aware of this when driving but it is also a constant problem for walkers and cyclists. The last and by far the most common type of light pollution however, is known as ‘nuisance light’, often caused by inappropriate security lighting or poorly designed flood lights to sports pitches.
Bad lighting that causes light pollution has many different affects on wildlife. Trees for example (growing in brightly lit areas) will keep their leaves much longer into the winter than is natural. It is quite common in town centres for Christmas trees to be erected next to deciduous trees that are still in full leaf. Birds are also affected by poor light. Research on robin behaviour has shown that the birds will sing at least three hours earlier in light areas compared to dark places.
It is the influence that bad lighting has on bats along the Thames that we are most interested in. Bat behaviour is influenced by poor lighting more than any other animal, having a negative impact on both their roosting sites and their feeding habits. As the river between Hampton and Barnes is one of the most important feeding areas for these nocturnal creatures in South East England the need for intelligent lighting is extremely important. To work out what lighting to have where however, is no easy task – there are simply so many different factors to be accounted for. Different types of lights affect bats in different ways and different species of bats are affected by different lights. For this reason, running alongside the current riverside user surveys we are also carrying out a number of bat studies to find out what species live and feed where. These are in partnership with local wildlife groups such as the Bat Conservation Trust. We hope that by the autumn we should be armed with all the information needed to make an informed decision as to what is the best way forward in lighting the river corridor. The first location that we are looking at is the Warren Footpath that runs between Richmond Bridge and Orleans Gardens. If you would like more information on the project or maybe fancy volunteering to help carry out a bat survey or practical volunteer day visit our website on www.thames-landscape-strategy.org.uk

> Read other Arcadian Diary entries
> Back to the homepage